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Produced by the NASA Center for Aerospace Information (CASI) https://ntrs.nasa.gov/search.jsp?R=19740018215 2020-03-23T09:10:32+00:00Z NASA TECHN ICAL MEMORANDUM ASA TM X-64812 I April 1974 George C. Mar. half Space Flight Center Marshall pac Flight Center) Alabama (NASA-T!I-X-64812) IISFe S nAB IIULTIPLE N74-26328 DOCKING ADAPtE , VOLUIIE 1 Final Re crt (NASA) 4 61 P He $26.25 eseL 22B FC· Form 3190 (Rev JUM 1971) Unclas G3/31 40531 TECHNICAL REPORT STANDARD TITLE PAGE 1. Rt;:flORT HO. 12. GOVERNMENT ACCESSION NO. 3. RECIPIENT'S CATA!.OG NO. 1\! II~II '1'MX fi4811 ; 4. T1T!.E MID SUBTlT!.E 5. R~PORT DATE MSFC Skylab Multiple Docking Adapter lIoril 1974 6. PERFORMING ORGANIZATION Ct>DE Vol. I 7. AUTHOR!S) B. PERFORMING ORGANIZATION REP!)R r # 9. PERFORMING ORGANIZATION NAME AND ADDRESS In. WORK UNIT NO. George C. Marshall Space Flight Center Marshall Space Flight Center, AL 35812 11. CONTRACT OR GRANT NO. 13. TYPE OF REPOR ... IX PERIOD COVERED 1~. SPONSORING AGENCY NAME AND ADDRESS Technical Memorandum National Aeronautics and Space Adminisb:ation Final Washington, D. C. 20546 14. SPONSORING AGENCY CODE 15. SUPPLt:MENTARY NOTES Airlock/Multiple Docking Adapter Project Office 16. ABSTRACT This report presents the history of the development of the Skylab Multiple Docking Adapter (MDA) , NASA Contract No. NAS8-24000, from initial concept through its final deSign, related test programs, mission performance, and lessons learned. The MDA performed with no Significant problems throughout the three manned Skylab missions. .~- -----"-- NOTE: Vol. I presents section 1 and 2 Vol. n presents sections 3 through 13 17. KE:' WOROS lB. DISTRI.UTION STATEMENT Unclassified - Unlimited I k GJ.. , I..{ H ~ CD (~ ,,,,Q "_ ., I~~cool ianao81 lIirl",,\-l. 8~ 19. SECURITY CLASSIF. (Or thb repcrt\ 20. SECURITY CL.ASSIF. (or t~ lite) 21. NO. OF PAGES 22. pRICE Unclassified Unclassified 461 NTIS MSF'C ... f onn 3292 (ttcv December 1172) For snte by Nationi'll Technical IMorrrtntton ServIce, SpringfIeld. Virginia 2~ 151 , ...... TABLE OF CONTENrS Volume I TABLE OF CONTENTS • • • • • • • LIST OF ILLUSTRATIONS • • • • • · LIST LIST 1. 2. OF TABLES • • • • • • • • OF ACRONYMS. • • • • INTRODUCTION. • • • • · 1.1 Purpose. • · • · • • • • 1.2 Scope · • • • • · • • 1.3 Summary. • • • • • • • • DISCUSSION • • · · • · · • · • 2.1 Module Description • · • • • • 2.1.1 History/Design Evolution 2.1.2 Test Evaluation. · · · · • • • 2.1.3 MDA Systems Description/Functions. 2.2 MDA Systems. • • • • 2.2.1 Structures • • • • • • • • 2.2.1.1 Structures System. • · • 2.2.1.2 MDA Shell. · • • • • • • • 2.2.1.3 External Components. • 2.2.1.4 Internal Components. • • 2.2.1.5 Materials. • · · • 2.2.1.6 Mockups & Trainers 2.2.1.7 Mass Properties. · • • • · • 2.2.2 Environmental Control System · • 2.2.2.1 MDA Ventilation System • · • 2.2.2.2 ATM COD Pane1/EREP Coolant System. 2.2.2.3 MDA Vent System. · · · • · · • · . 2.2.2.4 M512/M479 Experiment Vent Systems. 2.2.2.5 MDA Pressure Equalization System 2.2.3 Thermal Control System 2.2.3.1 Passive System • 2.2.3.2 Active System •• • · . • • • 2.2.4 Electrical System.. •••• • 2.2.4.1 Utility Outlets. • ••••• 2.2.4.2 Power Distribution Assembly ••• 2.2.4.3 Cable Assemblies • 2.2.4.4 Interior Lighting. 2.2.4.5 Exterior Lighting. it • • • • • • • • • • • • • • • • • • • · · • • • • · • • • • · • • • • • • • • · • · • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • · • • • • • • • • • • • • • • • • · • • • Page it vi xi xii 1-1 1-1 1-1 1-1 2-1 2-1 2-1 2-10 2-17 2-23 2-23 2-23 2-30 2-34 2-41 2-7.'; 2-101 2-108 2-115 2-115 2-121 2-141 2-146 2-155 2-163 2-163 2-190 2-215 2-216 2-219 2-222- 2-231 2-237 , 3. 2.2.4.6 Rate Gyro Six-Pack Cabling • · · · · · · 2.2.4.7 Rate Gyro Six-Pack Meter Checkout Cables 2.2.4.8 TV Mini-Moniter Power/Signal Cable · • · • 2.2.4.9 Adapter Power Cable/Modified Lunar Drill (Electric Nibbler) • • · • • • • • • • • • • 2.2.4,,10 MDA Engineering Mockup Unit (EMU) Article • 2.2.4.11 MDA One-G Training Article. • • • • 2.2.5 Instrumentation System • • • • • · • • 2.2.5.1 Signal Conditioner • · • • • • • • 2.2.5.2 Temperature Transducer • • • • • • • 2 wJ:.5.3 Pressure Transducer. • • · • • • • 2.2.6 Communications System. • • • • • • • • • • 2.2.7 Caution and Warning (C&W) System • • • • • 2.2.8 Television (TV) System • • • • • • • • · 2.2.8.1 Video Switch • • • • · • • • • • • • 2.2.8.2 TVIS • • • • • • • · • • • • • • • • • 2.2.8.3 Video Tape Recorder. • • • • • • • • • 2.2.9 Crew Systems • • • • • • • • • • • • 2.2.9.1 Crew Stations. · • · • · • · • · • • · • 2.2.9.2 Stowage • • • • • • · • • • • • • · • · • • • 2.2.9.3 Habitability (Comfort Evaluation). • • • • • 2.2.10 Experiments/ATM C&D to MDA Interfaces. • • 2.2.10.1 Earth Resources Experiment Package. •• • 2.2.10.2 Materials Processing in Space Facility (MPF) •• 2.2.10.3 SOO9 Nuclear Emulsion. • • • • • • • •• •• 2.2.10.4 Proton Spectrometer. ,. "',, ............ .. 2.2.10.5 Solar Radio Noise Burst Monitor (RNBM) •••• 2.2.10.6 ATM Coptrol & Display Subsystem • • •• 2.2,,11 Ground Support EqUipment (GSE). • • • 2.2.11.1 Struc tura 1. '. • • · • • • • 2.2.11.2 Mechanical. • · • • • · · • • • • • 2.2.11.3 Electrical. • • • • · · '- · • • • VOLUME II RELIABILITY PROGRAM • · • · · • • • • • 3.1 Objectives & Methodology · • • • · 3.2 Design Evaluation. • • • • • 3.2.1 FMl'.A . . • • • · • • · • • • • • • • • • 3.2.2 Critical Item List · • • • • • • 3.2.3 Trade & Special Studies. • · • • · • 3.2.4 Design Review. • • · · · • • • • · • • • • iii • • · • • 2-238 2-2.39 2-240 2-240 2-241 2-243 2-247 2-247 2-253 2-260 2-265 2-279 2-287 2-287 2-291 2-301 2-307 2-307 2-328 2-335 2-347 2-347 2-372 2-379 2-384 2-390 2-393 2-403 2-403 2-423 2-437 3-1 3-1 3-4 3-4 3-4 3-4 3-7 \ ' 4. 5. 6. 7. 3.3 3.4 Alert Investigations • • • • • Conclusions & Recommendations. QUALITY ASSURANCE PROGRAM • • • • • • • • 4.1 Design Review " '" " " ,. ,. , .. .. • " " - .. II " .. " " .. " . . • • 4.2 Implementation of Critical and Limi,ted Life Component Drawing.. ••• Supplier EvaluRtion. • · . 4.3 4.4 4.5 4.6 4.7 4.8 4.9 4,10 4.11 4.12 4.13 4.14 Material Evaluations ,. ,. " .. " " " .. • • Procuremer.t Control. "".." " " " " Test Pro~edure Approval/First Usage Validation • Nonconf-.>rmance/FA Evaluation • • • • • • • • • Configuration Verification and Change Activity • • Qualification Testing. • • • • • • • •• • Manufacturing In-Line Surveillance. •• Subsystem/System/Integration Test Hardware Review ,. " " " " Acceptance Manager. Mission Support • • • • • • • • • • • • • " . • • • • • • LOGISTICS " " " • " ,. " " " " ",... " ,. .. 5.1 Logistics Planning. • • •• •••• 5.2 Maintenance Analysis" " " " " """ " "" " 5.3 Spares Provisioning!Management • ••• ••• 5.4 Operation, Maintenance and Handling Procedures •• 5,,5 Transportation Planning. " " " , " " " " " .. .. " .. " 5.6 Development of Critical & Limited Life Component Drawing" " " " " " .. " " " " " " " Modification Instructions. • • • • Training of Contractor Personnel In-Flight Maintenance. • • • • • • • 5.7 5.8 5.9 5.10 Conclusions & Recommendations • • • SAFETY PROGRAM. • • • • 6.1 General ... " , • 6.2 Crew/System Safety 6.3 Conclusions ••••• 6.4 Recommendations. • • • • . . · . . .. . " " " " · . " " ii' " " " " " " • • • • • • • • • • • • • • • TESTING PROGRAM • • • • • • · . • • • 7.1 Test Requirements. 7.2 Component Testing. • • 7.3 Off-Module Testing •• 7.4 Structural Testing ••• 7.5 Module Testing - Denver. • • • • • • • · . 7.6 Spacecraft Systems Testing - St. Louis iv • • · . . • • • • • • • • 3-7 3-11 4-1 4-1 4-2 4-4 4-4 4-8 4-10 4-10 4-25 4-29 4-30 4-59 4-70 4-76 4-79 5-1 5-1 5-1 5-2 5-4 5-5 5-5 5-5 5-5 5-7 5-11 6-1 6-1 6-2 6-4 6-5 7-1 7-1 7-12 7-19 7-25 7-27 7-40 7.7 Integrated Vehicle Testing ~ KSC • • • • • • • 7-62 7.8 Mission Support Testing • • • • 7-90 7.9 STU/STDN Activity • • · • • • 7-96 8. MANUFACTURING. . • . · • • • • • • • 8-1 8.1 Articles Manufactured. • • • • 8-1 8.2 MSFC Build History • • • · • • · · • • 8-5 8.3 Manufacturing Techniques • • • • • 8-11 ~ 9. MDA PROGRAM CONTROLS 9-1 · • · · • • • I 9.1 Planning & Scheduling. • • • • • • 9~1 9.2 Configuration Control. · • • • • · • 9 -4 10. MISSION OPERATIONS SUPPORT • • • 10~1 10.1 General MMC Support Philosophy. 10-1 10.2 NASA/MSFC Support • • • · • • • • • 10-2 10.3 MDA Contractor Operation. • • • • · • • • 10-5 10.4 Backup Article and STU/STDN • • • • • • • 10-13 10.5 Vendor On-Call Support. · • • • • · • · • 10~17 10.6 Conclusions & Recommendations • • • • • • 10-18 11. NEW TECHNOLOGY • • • · • · · • • • • • • • • 11-1 11.1 Aerospace Applications. • • • • • • · • 11-1 11.2 Other Applications. · • • • · • • • • 11-3 12. CONCLUSIONS AND RECOMMENDATIONS. • • • • • 12-1 12.1 Mission Performance • • • • • • · 12-1 12.2 Testing • • • · • • • • • • • • • 12-10 12.3 Support • • • • • • • • • • 12~12 13. REFERENCES. . • • • • • • • • • · • 13-1 v • Figure LIST OF ILLUSTRATIONS Volume I Title MOh Program ilistorica1 '~"ents Early MOh Concept ~1Dh Ext,'rinr View • • • MDII Shell • • • • • • • • L-Band Truss Structure •• MDA Interior Arrangement. Axia 1 Ha tch • • • • • . . • • S190 Window and Mechanisms. Film Vault No.1. Film Vault No.2. Film Vault No.3. Film Vault No.4. . . . . P,, 2_227 2.2.4-7 Tubing Junctions •• 2.2.4-8 Cable Junctions •• • • · . • • • • 2-228 2-228 2.2.4-9 2.2.4-10 2.2.4-11 2.2.4-12 2.2.4-13 2.2.5-1 2.2.5-2 2.2.5-3 2.2.6-2 2.2.6-3 2.2.6-4 2.2.6-5 2.2.6-6 2.2.6-8 2.2.6-8 2.2.7-1 2.2.7-2 2.2.7-3 2.2.7-4 Cable Flammability Protection Cable to Connector Flammability MDA It·terior Lighting System • · . • 2-229 Protection. • • • • . . . . • MDA Interior Light Switch Assembly. • • MDA Running Lights. • • • • · . . . , . MDA Temperature Measurement System Block Diagram. • Bridge Completion Network Schematic • • • • • • • • Temperatu,e Transducer. • • • • Speaker Intercom Assembly • • • • MDA SIA ;~etwork • · • • • • • • • • • SIA Signal, Flow • • • · • • CSM/MDA Audio System. • • • • Personal Communications Assembly. • • • Crewman Communications Umbilica.l. • · • Lightweight Crewman Communications Umbilical. • Crewman Communication Control Head Assembly • Fire Detection Subsysten·, • • • Fire Detection Functional • • • • · • • UV Fire Sensor. , . • . • • • • • • • • • • • Fire Sensor Control Panel • • • • • • • • • vii 2-229 2-232 2-233 2-238 2-248 2-249 2-254 2-266 2-268 2-269 2-270 2-272 2-273 2-275 2-276 2-281 2-282 2-283 2-283 , . 2.2.7-5 Fire Sensor 'rest. Sky lab TV S·ystem. • • • • Video Switch. • • • TV Input Station. Video Tape Recorder , . • • • • • • • • • • • · • • • Crewman at ATM Crew Station (left VleW) Crewman at ATM Crew Station (right \il.ew). Crewman at EREP C&D Crew Station. • · . . • • • • . • • • 2.2.8-1 2.2.8-2 2.2.8-3 2.2.8-4 2.2.9 -1 2.2.9-2 2.2.9-3 2.2.9 -4 2.2.9-5 2.2.9~6 2.2.9 M 7 2.2.9-8 Skylab Crewman at EREP VTS C&D Crew Station • • • Crewman at VTS Crew Station • • • M512/479 El';periment Crew Station. Total MDA Workspace . . .. . • • • Equipment Nested in Mosites Foam. .. . . . . . · .. .. • • · . . • • 2.2.9-9 Equipment Stowed Between Partitions Padded with 2-284 2~287 2-288 2-293 2-302 2-309 2-309 2-311 2-313 2-313 2-314 2-315 2-329 Mosites Foam • • • • • • • .. • • .. .. .. • .. • • • • 2-330 2.2.9-10 Equipment Mechanically Clamped and Secured with Calfal'; Fasteners. • • • • • • • • • • • • • • • • • 2-331 2.2.9-11 Equipment with Clevis/Lug El';pandogrip Pin • • • • • Equipment with Clevis/Lug EREP Installation • • • • Interfaces with .. . . . . . . .. . . • Interfaces. • • • . .. .. .. • • • · . • • 2.2.9-12 2.2.10-1 2.2.10-2 2.2.10-3 2.2.10-4 2.2.10-5 2.2.10-6 2.2.10-7 EREP Data Frequency Spectrum. • • · . . .. · . 2-333 2-334 2-347 2-349 2-356 2-358 EREP Hardware Interfaces. • • • S190 Window Transmittance Requirements. S190 Window Reflectance Requirements. • • • • • • · . 2-358 IR Spectrometer Spectral Resolution •• •• M512 Materials Processing in Space Facility • • • 2-361 2.2.10-8 M5l2 Equipment Stowage Container •• 2.2.10-9 M518 Multipurpose Electric Furnace. 2.2.10-10 SOO9 Nuclear Emulsion • • • • • • • • . . • · . 2-373 • 2-373 • • 2-375 • • 2.2.10-11 Proton Spectrometer Installation •• • • • 2-381 2-384 2-386 2-390 2.2.10-12 Proton Spectrometer Detector Head Assembly ••• 2.2.10-13 Solar Radio Noise Burst Monitor Installation •• viii .... -'.a.' 2.2.10-14 ATU C&D Console • • • • • • • • • • • • • • • 2-395 2.2.10-1S BI/LCA Installation • • • • • • • • • · • • 2-400 2.2.11-1 MDA Trunn! oned Onto Rotation Fixture. • • · • • 2_lfOS 2.2.11-2 MDA Trunnioned to Horizontal Attitude after Mating to A.>1 • • • • • • • • • · • • · • · • • 2-406 2.2.11-3 MDA Trunnioned to Vertical Attitude for Stacking to FAS. " • • • " • " " " • " , , . . . , . . " " 2-407 2.2.11-4 MDA in Transportation Fixture Offloaded from Guppy. 2-409 2.2.11-5 MDA on Height and C.G. Table •••••••••••• 2-411 2.2.11-6 Equipment for Protection and Access at the Radial Docking Port. • , , " " . • • " " • • 2-413 2.2.11-7 Horizont.al Access Platform •• • • • 2-415 Hoist and Track Installation. • • • • 2-416 2.2.11-8 2.2.11-9 ::.2.11-10 Platform and Ladder Assembly. •• •• · . • • 2-417 ~IDA Tra1.ner Erected to Vertical Position. • • • • 2-420 2.2.11-11 MDA T~ainer on Support Stand ••••••• 2.2.11-12 Desiccant Breather Assembly (SKS20FL5300) • 2.2.11-13 Shl.ppinr; Cover Assembly (SKS20FL5500) •••• • 2.2.11-14 Test LJ.ghtin:z; Fixture ••••• 2.2.11-15 NDA Checkout Fixtt're •••••• 2.2.11-16 EMP Checkoul: Fixture ••• . . . • • • • • • • 2.2.11-17 Proton Spectrometer GSE Mating Fixture. Television GSE " . , " . , . " . . , , . , , 8190 WindOl, Assembly Preflight Tester • • • 2-421 • 2-425 • 2-426 2-437 2-440 • 2-441 2-442 2-442 • 2-445 2.2.11-1S 2.2.11-19 2.2.11-20 TV GeE Input Rack , • , • , " " .. , • 4 • • • 2-447 • • 2.2.11-21 TV GSE Output Rack ••••••• 2.2.11-22 HDA Connector Dust Cover Kit. 2.2.11-23 BI/LCA Func~iona1 Test Set. 2.2.11-24 T027 TV Teot Adapter •••• • • VOLUME IT MDA Ml,RS VD Schedule Summary. • MDA DR VB Schedule Summary •••• BDA DC&R, FA, and CAPS Summary. , . .. .. • 2-447 2-450 2-451 2-452 • • • • • · . . ..... .. 4-13 • , .. • .. 4 ... 13 • 4.7.1.2-1 4.7.1.2-2 4.7.1.2-3 4.11.1-1 Skylab Standardization/Certification Board. 4-1S 4-60 ix II , , 7.1-1 7" 1-2 7.2-1 7.2-2 7.2-3 7.2-4 7.5-1 7.5-2 7.5-3 7.6-1 7.6-2 /,7-1 7.7-2 7.7-3 7.8-1 B.l-l 8.1~2 B.1-3 8.2-1 8.3-1 8.3-2 8.3-3 10.1-1 10.2-1 10.2-2 10.3-1 10.3-2 10.3-3 10.4-1 NDA Test Requirements Definition Tree • • NDA Teot Requirements Implementation Tree Test Requirements Matrix. • • • • • Qualificatiou Test Program Sequence • ComponcnC/Sub'\ssemb1y Ql'alification • • • · • • • • · 7-4 • 7-6 • 7-14 • • 7-16 · • 7-16 Test Documentation/Test I'rogram Sequence •••••• 7-18 MIlA Flight Article Denver Te'}t Flow • • • • • • 7-29 HIlA Flight Article Denver Schedule MIlA Ecckup Article Denver Schedule • • • • • • • 7-30 · . . . .. .. • 7-39 Flight Article-AM/MDA Integrated Test Activities at St. Louis. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .... 7-43 Backup Ar.Cicle-A:i:l/MllA Integrated Test Activities at St. Louis. • • • • · • v • • • KSC-AWHIlA Test Flow (0&0). • • · KSC-Ll1:!/l·mc'. Teot Flow (VAB). • • • Al'!~\DA KSC T(1st Schedule. • • • • St-y1ab TV System-STU/STDN • • • NDAmw. vlI ••• • • • • !-1DA Oile ... ,J T!.""uiner NDA DHU .. G .; e .. •• · . . .. .. • • • • • • • • • • • • • • • • • • • · • • · • • • • • • • • • • • • • • • • NDA Pressure Vessel Structure Assembly. • • • · • Sump!.e Hauufo.cl:uring Flow • • NDA Installed in Factory •• NDA Installed in SSB. • • • • • • • • • • · . • • • • 7-54 7-61 7-64 7-66 • 7-95 • 8-2 8-2 • 8-3 8-5 • 8-13 • 8-15 • 8-16 Inter.nul NNe Sky1ab Mission Support Interfaces. • • 10-1 Sky lab Flight Operations Management Support Plan Intcriaces. ~ • • • • • • • • • •• • • • 10-3 NSPC Sky lab Operations Organization NDA MisGion Support Organization. • Denver Support Room Organization. • • • NHC/NllA. Document Review Organizati.on. MDA Backup Article Mission Support Flow • • • • · . . • • · . • 10-4 • l.O-6 10-10 10-14 • 10-16 , Table 2.2.1-1 2.2.1-2 2.2.1-3 2.2.1-4 2.2.2-1 2.2.3",1 2.2.3-2 2.2.3-3 2.2.3-4 2.2.3-5 2.2.5-1 2.2.5-2 2.2.5-3 2.2.8-1 2.2.8··2 2.2.10-1 2.2.10-2 2.2.10-3 3.2.2-1 3.2.l~-1 7.3-1 10.5-1 LIS'£ OF TABLES Title Page }!DA Film Vaults • • • • • • . ... . ... . ... . . , . • 2-65 Stowage Containers • • .. .. • • • • • • • • • • 2-72 Resistance of Metals to Stress Corrosion ~r.acking. • 2-76 EREP Weights • • • • • • • • • .. ... • • • • Coolant Loop Dropout History •• MDt!. CEI Requirements Summary - TCS •••• •• MDA Rt!quirements Summary, AMMDA and MDA/CSM ICDs. }!DA Requirement Summary - Expedments. Passive MIlA TeS An.alyses • • • • • • • • Active MDA TCS Anal.yaea. • • • • • • • • · .. . . • • Temperature Transducer Qualification Test Results • 2-113 2-137 2-164 2-167 2-1.69 2-171 2-191 and Disposition. • • • • 18 temp~rature rise imposed further limitations on available power. This effect restricted the use of the HDA heaters with a resultant drop in HDA internal temperatures. Once the OWS problems had been Significantly reduced through parasol deployment and par- ticularly after deployment of the remaining Solar Array System (SAS) Wing, when power was no longer critical, the MDA heaters were activated and internal temperatures were restored to normal. 1-3 The remainder of the ~lDA, A. A A A A A Systems Sim ! assurance Flight kt--!-- Launch : Test Test I Storage Complete Complete , ~ I I t- Hission Support -I B!\.CKlJP ARTICLE I i A A ~REP Insta1~ation I I A I. Clo Complete i Hardware Final SL 1/3 SL 1/4 Integrity Flight Flight Flight Review Readiness Readiness Readiness I Review Review Review I REVIEWS I I I A -A A ~~ A . F~gure 2.1.1-1 (Concluded) S-IV B -- (3) Second concept in November added 2 radial ports to accommodate: • Lunar Mapping & Survey System (LM&SS) • • Resupply Module (RM). Note: Fi ure 2.1 . 1-2 illustrat es this concept with LM/ATM, RM and CSM docked. SOLAR PANELS RACK/ATM LM MDA a&SUFFLY MODULE Figure 2. 1.1-2 Early MDA Concept (4) November version described as (ol l ows: • Main Tunnel : 65 inches dia x 38 inches length . • Radial Tunnels: 56 i nches length. 2-6 • Ench Port: 34 inches diameter. • Gross Weight: 900 lhs. • Thermal Control: Passive. • Environment"l Control System (ECS): O2 nwlleup from AH. • lilectricnl: Wiring from AH to ports. (5) 'fhird concept in 1966 enlarged the HDA as foll()t~s: • Nain Tunnel: 1.15 inches diameter x 84 incllOs length. • Radial Tunnels: 20 inches length. • Gross Weight: 2000 Ibs. • Electrical: Added lighting to second concept. • Instrumentation & Communications (I&C): Dis- play/monitor pressurization and consumables transfer. " Experiments: Stow S017 panel, stot~/operate S063. Il. Year 1967 - (1) 1966 concepts resolved into preliminary design as announced by the National Aeronautics & Space Ad- ministration (NASA) in H .. rch. This version described ~F follows: • Nain Tunnel: 120 inches dia. x 180 inches length. • Four radial ports. (2) Subsequent to announcement of the Harch version the following events occurred: • Running and internal lights specified. • fuo radial ports deleted (D!&S,S and RM). 2-7 .. Added experiment RtO!~age/oper"tionnl require- nlents. • HDA identified as cllndidllte for contingency workshop study. C. Year 1968 - • S009 Nuclear Emulsioh added. • Expanded ECS to include fans/ducts, heaters (16 wall, 3 port, 2 window cranlt), (md 2 vent valves. • Electrical expanded to include 4 auxiliary power out- lets and power distribution capahility. • I&C expanded to include voice communications, instru- mentation sensors (temperature), signal conditioning, ;;md multiplexing (2 low level and 1 high level). • Several medical experiments identified for stowage/ performance in the ~IDA including an Experiment Sup- port System (ESS). These items \~ere eventually deleted from the HDA. D. Year 1969 - • Dry Workshop concept adds ATM Control & Display (O&D) Console, deletes OWS experiment st'orage. • ~IDA design, development, integration, fabrication, test, delivery contract to Martin Harietta Corpora- t i on (1IHC). • ~IDA shell provided by Marshall Space Flight Center (MSFC) • o Reduced radial port requirement to one for a backup CSH. .. S190 Multispectral Photographic facility added • .. H512 Hatedals Processing Facility added. • Film Vaults added. 2-8 E. Yenr 1970 - • 8191, S192,S193 and S194 added (Earth Resources Experi- ment Package, EREP, ~omp1eted). • RNlIM added. • Inverter/Lighting Control Assembly (l/LCA) added. • U/V fire sensors added. • Orbital Assembly (OA) TV system "omponents added. • I'light shell received in Denver. • MDA Critical Design Review (CDR) held in Denver. • N:l/MDA Crew Station Review (CSR) held at St. Louis. F. Year 1971 - • ~1DA GSE identified for component install/remove capability for Denver, St. Louis, KSC. • EREP pre-installation tests in Denver. • Crew Compartment Fit and Function (C2F2) held in Denver. • Flight article acceptance review held in Denver. • Flight article shipped to St. Louis. • MSl2 facility experiments expanded. • Backup shell received in Denver. G. Year 1972 - • Video Tape Recorder (VTR) added. • AM/MDA mated at St. Louis. • EREP bench tested at St. Louis. • Experiment }lS18 added. 2-9 • AH/~mA C2F2 completed ilt St. Louis. • Altitude teqts completed. • EREP installation completed. • Electromagnetic compatibility (EHC) tests on AH/HDA. • Shipped AH/~IDA to KSC in October. D Initial pre-launch including inverted docking tests completed at KSC. • Backup ~IDA shipped to St. Louis. II. Year 1973 - ~ Completed pre-launch tests at KSC. • SL-l launched in Hay. • Two Skylab missions completed and final initiated. 1. Year 1974 - • Skylab mission completed. 2.1.2 Test Evaluation The ~IDA test program was structured to make use of program developed mockups, simulators and test hardware to supplement flight and backup hardware testing. The test and design verifi- cation hardware developed and used on the program included the follOWing: ., Zero G Hockups (S configurations) • ., Neutral Buoyancy (N/n) Hockup. .. Engineering Ho~kups (EHU) • • One G Trainer (developed from EHU). e Static Test Article. • Dynamic Test Article (DTA)(developed from static article). 2-10 • Development Nockup (DNU). In ~ddition the above programs, the NDA flight and backup nrtic1es were subjected to 11 comprehensive seri8 NDA. Hard docking was accomplished three times on the 3:dal [lort. 2-28 E. Concluo:!.one and P.eccw.IUollun£:.;.ono " The highest loads were dc;:ived from the Z'm,art of the pressure shell. The ,,1:her frames and longerons \,ere nttached to the skin \,ith mechanical fasteners. To minimize leakage, sealing \,ashers \,ere installed under the heads of all skin penetrating fasteners, and sealant \,as applied to the surface of the longerons and frames that came in contact \,ith the shell. The lonr,erons .. ere designed to provide t\,O parallel facing s'Jl:'faces on adjacent longerons to facilitate the attaching of lntercostals. Each of the t .. o faces had t .. o rOl,s of blind nuts in- stalled on three-inch centers, providing capability to install sup- port hard .. are at any location in the HDA. The cone consisted of four machined panels \,elded together. The panels .. ere .250 inches thiclt in the \,eld lands and around a vent cutout, and .125 inch thick in the remaining areas. A ring bolted to the for .. ard end of the cone !,as uE'e,d to attach the doclt- ing port and hatch ring. The cone \,as attac:'.1ed to the cylinder by !;elding a common frame to the aft end of to" cone and the for\,ard end of the cylinder. The t!;O docking ports .. ere built-up cylinders consisting of machined aluminum rings at each end !;ith a center filament .. ound fiberglass cylinder to provide thermal isolation. All mechanical joints \,ere sealed to minimize leakage. Both docldng pOl'ts had provisions to install a drogue and provide the proper intel'fac~ for CSH docking. The axial port had provisions for transferring pO!;"", communications nnd instrumentntion bet!;een the HDA and the rio cited CSH. The rndial port did not have these provisions since it .. as intended for rescue only. C. Test - Several and leaka~e integl:'ity. test article. Pressure and Backup Articles. tests .. ere perfol:'med to vel:'ify stl:'uctul:'al Structul:'al testing !;as done on a static tests .. ere also conducted on the Flight (1) Flight Article - The Flight ArticlE1s (including Backup Article) "as subjected to leak and proof pressure tests. Pressure tests "ere l:'un at MSFC on the basic shell and again at ~jHC after all 2-32 major penetl'3tiono were made. Both l'1oduJ.es pallsed proof pressure testing without ~my problems, Leakage testa were passed after minor repairs as noted in Section 7.5.4. (2) Static Test Art!cle (8) Structural Description - The MDA Static Teat Article consisted of an MDA shell with docking ports, windows, and Infrared (IR) Spectrometer fitting. Testing was conducted at MSFC in January and February 1971. (b) Test Objectives • Verify structural integrity of the MDA structure for docking loads and loads imposed on local atructure by equip- ment, experiments and experiments sup"port hardware. • Determine deflections and stresses of the critical loads conditions. • Verify analytical methods. (c) Static Test - Nine separate conditions were tested. Six conditions simulated worst case pressure and docking/latching loads. Three conditions were tested to verify structural integrity for local loading conditions. The local loads were derived from the worst case, static equivalent combination of steady state acceleration, random vibration and vehicle dynamics. A factor of safety of 1.4 was applied to design limit shear, moment, and axial loads, and 2.0 to presaure loads. Details are contained in ED-2002-l264. (d) Conclusions - The MDA Static Test Article verified the structural integrity of the MDA shell while subjected to the critical loading conditions. 2-33 D. Hiosion Results" The shell functioned us plunned. All intern>!l >!nd e"torn>!l equipment U>![J intact after orbital ir.oertion, aSH docldng l~ao achieved, and pt"eooUl:e was maintained without Significant leakage. E. Conc1usiono and 1~ecommendation8 " The baoic shell configuration was conceived for the wet workshop. The intent was to make the shell 0 pure monocoque (tlnotif£ened skin carry" ing all loads) with the longerono usee! only for attaching eqUipment and distributing loads into \:be okin. When the mission was changed to the dry worl,shop concopt, the !-IDA was required to support additional. equipment: for which the shell was not Originally designed. The eAistinc longerons were modified to toke flight loads and Cht'ee ring frames were added to the shell to meet these new requirements. All changes were mode before completion of st.ructural teot:ing, so that structural integrity of the "as flown" configuration was verified. The shell performed its function during the complete Skylab mission without any problems. However, during the outfitting process, many problems were encounte~ed using the blind nuts in the langerons. Galling occurred while inotalling bolts, seme nuts came loose, the nuts were not located in the proper place for all installations, und repai~ techniques caused chips to fall into the longeron cavity. Future pressure vessel designs for manned spacecraft should utilize a more efficient structural configuration, minimize the usc of blind nuts, and eliminate skin penetrations to the grcatest extent possible. One suggested method is to use integrally machined skin and stringer construction. This design is efficient in carrying loads and minimizes skin penetratic>us. The flanges of the stringers would permit equipment mounting with standard nuts and bolto. 2.2.1.3 External Components The major components that were luounted eAternal to the shell were the L~Band truBo, radiators, meteoroid shield, and insulation. Other items included docking targets, acquisition lights, S191 and S192 experiment structure and HDA vents (HDA vacuum vent, H512 vacuum vcnt, H512 bottery vent). The major components are considered in further detail. helow. Other items are described in the respective sections of this report; i.e., lights under Electrical Power System, vents under Environmental Control System, and cApel.'iment sunder Expedumnts. 2-34 A. L-Band t rus (1) Design R quir m nts - L Band truss d sign requir m nts w r e : o Withstand prelaunch, launch, asc nt, and orbital environments without p rmanent d formation. o Position exp rim nts 80 that th loc£tion and vi wing r qui rem nts wer met p r: leo 13M1352 5 leo l3M13513 (519 Int rfac R quirem nts) (Proton 5pect romet r Interface Requi r ements) o Attach t o MDA so that cone stif n ss would not be aff ct d . o Do not int rfer with C5M docking and AIM de ployment o r operatio n. (2) De8cription - Th L-Band truss co nsisted of a luminum tubula r members we lded and bolted together . (Figur 2.2 .1- 3) . Addi t io na l fram 8, - I J Figur 2 . 2.1 - 3 L- Band Truss Structure 2- 35 brm:keta, etc. Here attadled to the truss to provide interfaces for the antennas, L~Band Electronics, Proton SpectrOlnoter, and the I/LCA. All truso membm:s ~,ere wrapped with aluminized mylar tape to help maintain thel-mal b3lance withill the ~11lA. Th~ tl'USS H3S configured to interface with the HIlA ut three points. One point wus an existing lifting fitting ut the cone/cylinder juncture located to one side of the Z uxis. A second point wus equidistunt from the Z uxis to structurul provisions added to the cone/barrel j:mcture. The third atta<.'h point was to an udjust(lble link that attached to the axial ,10cl~" ing port/cone joint. ,3) T~st M The follOWing tests w~re conducted on the truss. (a) Assembly Testing - A prototype L~Band truss ~;ith experiment mass simulutors ~,as installed on the DTA and t~sted as part of the vibro" acoustic test. An analySis perfol-med using load factors obtainetl :l:rom the vibroacoustic test showed n safety factor of 3.0; therefore, structural tusting was not r~quir~d. The load factors obtained were lQ1,er than sh01m in IN~STN-AD-70-L A deviation ~ms granted which l'tlduced the composite high level raltdom vibratiOll level from 8.9 to 2.225 grms. (b) Element Tests - Element tests ~,ere conducted on welded 5456-1t111 Aluminum alloy (truss mat~rial) to detcl'l11ine the al1mQables in the lias wclded" condition. These values were uscd to size members and in the finsl tl'llSS una lysis • (4) }lission Reoults ~ Thel'C were no anomalies reported in\,olvinr: the L~Band truss. Photos tulten during fly aroUl~d insp~ctions showed tho truss am\ associated hardware intact. (5) Conclusions and Reconunendations - The original dosinn concept of the L-13"nd tl"USS HOD a configuration that was attached to the ~lDA at four fittings at the cone/cylinder junctu~e. Thio HaS tocomply with the ground rule not to stiffen the cone, The material for this truss waB 6061 aluminum, which was to be heat treated after welding. It was obvious, from the geometry of the truss, that heat treating would cause distortions and that the truss would not meet requireme~ts. A study wao conducted to come up with a nCl~ material and a more efficient design. 5456-Rlll aluminum was selected because of its high "as welded" allowables, A three point attachment truse design was developed which caused no increase in cone stiffness, The results of the study produced the ~s-flown L-Band truss deai[ln. nle basic truss members were welded to[lether with a minimum of problema; however, ~~hen the experiment support proviSions were welded to the tubes, distortion occurred. Additional machining operations and shimming were required to fix this problem, It is recommended in future deSigns, that any critical interface support bracketry be attached with hardware rather than welding, B. Radiators nnd Meteoroid Shield M (1) Design Requirements M Meteoroid shielding design requirem~nts were: • Withstand prelaunch, launch, and ascent en"ironment. • ~!et,t .995 probability of no pressure shell pt'netrLltion. • Meet ,995 probability of no electrical Wiring penetration. i , , (2) D~ocription - ApproximatGly 75% of the ban'el portion of the HDA 1MB covered I,ith radiatora. They were conatructed of .030 inch magn~sium with coolant tubec attachad. and \-Iere finished I,ith a opecial reflecttve IlaS held in the closed position with six ovorcenter latches. The latches "ere controlled by linkages attached to a central shaft. He,dles Here attached to the shaft on both sides of the hatch, thereby a11o~ling opening and closing from either side. The handles were restrained in the closed poaition during launch and orbital storsge periods by a launch lock which was locked from the outside only but could be unlocked from either side. Zach hatch was ol)erated by moving the oparaging handle through an angle of appr~ximately 60 • Typical operating force on the handle wss aix pounds, although any force up to 25 pounds was considered acceptable. A ball plunger detent device held the h8ndle in either the open ~r closed position. After the le.tches were relessed, the hatch was free to swing open on hinges to the full open (stowed) position, where it was restrained by bQll plungers in the hinges. A force of approximately seven pounds was required to free the hatch from the stowed position. Each hatch contsined a delta pressure gage and a pressure equalization valve which are described in Section 2.2.2.5. The edge of the hatch was 8 lip .,hich depressed a silicone rubber seal in the M~ shell docking port ring to achieve s pressure tight closure. The amount of seal indentstion >laa limited by six mechanical stops to prevent overstressing of the seal. The axisl hatch included a tool box mounted on the CSM side with t.ools fo~ contingency opening of the hst::h in event of " mechanism malfunc·tion or a hatch to 8eal stickinl~ problem. The seals were held in their retaining rings by a p~essure sensitive adhesive (aee Section 2.2.1.5) which enabled the crew to replace a seal during the mission if required. 2-45 (3) Test - Component qualification testa of the hatch "ere uoed to demonstrate the adequacy of the design for launch and orbital conditione. The flight hatchee "ere tested tor lo~ltoge before inota11ation and for hondle operating forces after installotion. The hntch seal '189 tea ted separately t.> o~sure ito integrity under long life thermal vacuum conditions. Qualification teoto verifiod the final hatch design for pressure, vibration, pyrotechnic ahock and ultimate handle forceo. Dataile of the qualification teeto are given in tt10 test reporto (0436/40-SL- 111-2 and 0436/I.O-SL-126-2). Teate t1ere conducted on oactionll of hatch oea1s to detormine tho ability of the 9001 to t~ith9tand long periods of timo "hill!! compressed under operational conditione and to determine whether sticking of the Deal to the hatch conld become a problem. Test epacimeno wore four inch long pieces cut from n production seal. The Dpecimens were compreAeed in a fb,ture resembling 0 aeal retaining ring, and placed in a vac'~um chamber with controlled temperature. Periodically, specimens were removed from the chsmber, pulled to measure sticking force, and examined for damage. The test program HaS auccoosfully concluded after eight months oxposure of the final seal configurlltion with no dalllllge snd acceptably small sticking forces. Another teat of a full- size aeal wae conducted to measure leokage degradation over eight months of compreooion. This teat, which waG at room ambient conditions, showed negligible leakage of the seal a fter the full miaoion time. The hatch aeal testa are described in detail in ED-2002-204B. (4) Mission Results - The axiAl hatch operated normally during activation and deactivation by the three Skylab cre"o. The contingency tools were not required. The radial hatch "00 not operated. 2-46 ', •. : (5) Conclusions and RecoDllMmdationo - The Mn.~ hatch design '·IS8 furnished by th", Government. When responsibili ty for the deoign "'''13 "ssiSlled to MMC aome ne~1 loading requirements '~(lre imposed. These made neceseary Dome detail design chsllges and some parts ",ere changed from aluminum to ateel, but the basic design remained the same. Hinges ",ere added to the hatch at this time. Mechanical stops were added to the hotch to 1 tmit indentation of the aeal ,·/hen a potential failure mode '~a9 sho'1n by a tast. Sticking of the seal to the hatch indenter ,~a8 recognized aa another potential failure mode, and contingency opening toolo Here designed to deal ~/i th this problem. A tool bOlC waD added to the slCial hatch to hold these tools. The original seal "IaS made of an extremely soft and fleldble Dill.cone rubber. Several oesls were successfully made of this material and two were installed in the }lOA flight article. Later, an attempt ,~aB mode to procure additional spare sellls but the vendor '108 unable to supply satisfactory parts. The base polymer proved to be an elcperimental material on which ,~ork had been discontinued becauae of production problems. At about the Dame time, oticking began to appear in the thermal vacuum teato. The decision ~Illa made to use nn alternate material, a conventional silicone rubber formulation of medium hardness. No production problema wera encountered and a sufficient number of oea10 ~IllS fabricated for the flight and backup articles, test and oparss. The tendency to~/ard ouctting bet~~een the seal and metal lip waD effectively counteracted by treat- ment of both ourfacea. The silicone rubber had talc burnished into the sualing surface, snd the hatch lip wss COS ted by an aeroaol spray of teflon particles in an acrylic binder. 2-47 I The honeycomb sandwich design of the hatch was not basically adaptable to deoign changes, but no serious problems were encountered in design- ing stop fittings and a tool box to add to the completed hatch. Similarly, the seal was replaced although the original design did not anticipats thio. Several problems with the hatch resulted from not designing for ground handling conditions. The Dteel ball plungers that I~ere used to hold the hstch in the open poof.t.ion wore grooves in the sluminum hinge fittings because of numerous open/close cycles during final assembly and check- out of the MDA. The solution was to remove the ball plungers until just before launch. A few retaining rings were lost from the hatches dur- ing trsnsportstion and handling. The precise CaUse of the problem could not be ascertained, but the ringa were in a vulnerable location and apparently were inadvertently knocked off. The solution was to change to a heavy-duty ring design. The MDA docking port hatchea performed satisfactori- ly throughout the Sky lab mission. The axial hatch was opened and closed three times. The radial hatch wes not operated. Experience with the MDA hatch leeds one to the con- clusion that early consideration of ground handl- ing and prelaunch operations would have had a ben~ficial effect on the hatch. Several rework operationo could have baen eliminated and a laat- minute installation avoided without compromising the weight, cost or flight worthiness of the hard- ware. C. Windows - The MDA contained four single-pane windows which were installed in the structural shell of the vehicle. The S190 windoll was the largest of these and it served as a viewing port for the S190 camera. Whenever the camera was rotated back to its atowage position, a removable transparent cover (safety shield) was installed over the window's inside surface to protect the glaBs from accidental damage and to act as a redundant pressure oeal in caBe the S190 window had failed. 2-48 The S191 window was used with the Viewfinder Tracker to locate EREP target sites and point the S19J Infrared Spectro- meter at them. The other two MDA windows were used to pass visible and infrared light rays through the MDA wall from the external sensor of the S192 Mu1tiband Scanner to the internal detector. (1) S190 Window - (a) Design Requirements - Two distinct sets of requirements wer~ imposed upon the S190 window, one covering structural performance and the other dealing with optical parameters. As an item of primary structure, the S190 window complied with all applicable require- ments identified in the CEI Specificati~n and in the Cluster Requirements Specification (CRS). Structurally, therefore, the window was desi~ned to maintain structural and pressure leakage integrity by withstanding: • Vibroacoustic loads • Shock loads • Pressure • Internal operating environment • Temperature extremes • Van Allen Belt radiation " Micrometeoroids • Accidental impacts from the crew The window's performance was demonstrated by analysis and extensive testing as described below. As a viewing port for the S190 Multispectral Camera, the window was designed to comply with the requirements identified in the CEl Specification and in ICD 13M1220l. The require- ments included specifications for: -- - • Wavefront distortion • fransmissihllltv • Reflectance • Glare • Contamination control • ~13tBture condensation prevention • Crew protection trom ultraviolet light Optical pcrformance was demonstrated bv test. (b) Dcscription - The S190 window (Figure 2.2.1-6) WS8 a siude pane of borosilicate Figure 2.?1-& SlqO Window .ud M~cl\.nisms 2-50 .... , .. cro\lith 011 applicable requiremonta identified in the eEl 3pecification and in the 1.-57 cas. The safety shield was designed to provide sealing redunaancy for the S190 Window and to withstand pressure, impact and vihroacoustic loads. Performance was demonstrated by teoting as described below. (b) Description - The safety shield was a remov- able internal cover for the S190 Window. It wes positioned against the i~side of the window frame and hand-fastened there by a crewman whenever the 8190 E"peri'llent wall rotated into its stowage position back away from the window. The safety shield consisted of a high~strength glass panel (Corning Chemcor 0315), 0.290 inches thick, mounted snd sesled in an aluminum frame. The frame included an a-ring on its mounting surface to provide sealing redundancy for the 8190 Window. The function of the safety shield waS to protect the S190 Window from possible dsmsge resulting from the impsct of loose objects within the MDA and to act as a redundant pressure seal in case the S190 Window had failed. The safety shield waa launched in its stowage position on the aft end of Film Vault 4. (c) Test - Acceptance tests of the glass panels included both structural and optical tests. Structural integrity was demonstrated by pressure testing and thermal-shock testing o to 540 F to screen the panels for hidden flaws. Optical clarity was assured b:r test- it.g for high transmittance and absence of distortion. Acceptance and qualification testing of the safety shield included impact resistance, Vibration, proof pressure and leakage of both the glass seal and a-ring redundant seal. (d) Mission Results - The S190 Ssfety Shield performed normally throughout the mission. No problem or difficulty was reported by any of the three crews. 2-58 (e) Concluoions onu Recommendatiolls - Early concepts of the MDA includei an internal "Indo" cover ,.hose primsry functions "ere to protect against internal impacts and to shield the cre" from overexposure to ultraviolet (UVj rays. The ultraviolet shielding became less important ,.hen tr.e 8190 l-lindow material was changed from funed silica to BK-7 glass becsuse the BK-7 absorbs most of the UV tight, Although the glass material used in the safety shields absorbs the residual UV light that pssoes through the BK-7 glasB. it "las not selected for that reason but because of ita high impact resistance and because of its proven per- formance in the Lunar Module Hindows. Polycarbonates and acrylics "ere also conSidered as candidate materials for the safety shield panel but "ere rejected primarily because of flammability problems. It is concluded that the 8190 Safety Shield met all of its requirements during the Sky lab mission. It io recommended that the safety shield design be uaed wherever possible in future spacecraft to protect oingle pane windows from damage and to provide them "ith pressure leakage redundancy. D. 6190 Window Extsrnal Cover (1) Design requirements - The cover Haa designed to meet the following criteria: • Provide meteoroid protection for the 8190 window equivalent to the adjacent structure. • Minimize heat loss through the area over the window. • Provide contamination protection for the windo". • Provide venting for the cavity bet~leen the cover and t~indow to accommodate pressure changes during transportation, purging sou the ascent portion of the flight. 2-59 o l'1ithetand all imposed loads. o Meet outgassing criteria. Another protection the cover provide1indow cover alone. A development cover waS included in the mechanism tests of vibration, acoustics and operating cycles. Although the sole purpose of the cover in these tests was as amaas simulator, th~ cover successfully withstood all test environments. (4) Mission Results - The window cover successfully performed all required functions during the Skylab mission. (5) Conclusions and Recommendations - The window cover was a conventional fiberglsss honeycomD construction designed to minimize the effects of tolerance buildupa in the components. The panel WaS first aBs~mbled and bondad in an autoclave. The edgea and inserts were then bonded by uSing a room temperature curing adhesive. The panel waa baked to release all volatile producto EO the cover Hould meet out- gasoing criteria. 'fpc' J.ntegIDA Tool DOlI: (M) 144 SIZE (mct!ES) 7.00 X 16.50 X 40.()O . 5.50 X 8.50 X IB.OO 12.50 Dis. X 23.25 10.75 " .. 11.50 X 21.50 11.00 X 22.75 X :30.00 3.60 X 7.50 X 25.60 10.00 X 15.25 X 17.50 COIITEIITS LOCATION IN MIlA TYPE OF' Th"TERNAL RES'i'RA tNT TYPE OF LATCU LAUNCH LOCK ICD 10 Scalod CO2 Canisters Botwccn tangeranG 1 and 2 Friction Between Mositen, Squeeze Tabs Hair Pin CUp at Approx. Sta. 3544 Pads and Springs and CO2 in Lid. with Pull 1:n!13427 Canister. Rinr; • 4 Control Heads Between Longerooa 2 and , Profile Cavitfcs in Hosites DialarehaB at Approx. Sta. 3533 with Interference between 2 Dlalatchas Torqued t- 13M13424 Control Head Bnd Moaltes. 25 In.-Lb. Close Fit Between 110dtes 4 "5054 Return Containers Fotvard Side or FiltD Vault Pads and 5054 RCl[Urn Coo- 2 Flush-Type Preload in No. 2. Betveen Longcrocs 5 tainers. Bcts St..:'ap for Tension Latches. 1~0740B and 6 at Approx. Sta. 3522 Each CODtsincr. Latches. FUght Manuals Bet'Veen LOCl;,erono 1 and 2 Adjus.table Ellistic Fabric SquecT.c Tabs nair Pin CI itl at Approx. SU. 3522. Separator Partir-lcDI". in Lid. with Pull None Rinl;,. Misc. Co=1. Equip., ~OMA. Between Longerons 2 and :3 Cctparto:cntc Lined with SqUCCl!:C Tabs Hair Pin CUp MDsites and Re~ovable Mosite Return Containers. Spare Betueen Stations 3487 and in Lid. with Pull None Ucbil1ealo, I\ceutron Tray. Beta Straps for timer, etc. 3522. Ring. Zero-G Restraint. Batcb Contingency CSU Side of the Axial Hatch profile Cavities in Mosites 2 calfax Fsotecers Opening Tools Beta Straps for ZI::~o G Fasteners torqued to None Reslraint. 30 In.-Lb. In-Flight Maintenance Aft Side of FilC! Vault No. , Profile Cavitiea in Mosltes 1 Pip Pin Por 2 Pip Pins Tools and Re.,air Between Longerona 7 and 8 with Velcro at Bottom .If Dra~r. per DrS\O"Cl· None Materials. at Approx. Sta. 3487 C&vit, or Beta Straps. Table 2.2.1-2 Stowage Containers , I .. J """-" (5) Conclusions and Recommendations - Mosites f"am .. as used as the cushioning material t" provide environ- mental protect j"n for stm1er, if possihle. • Container doors, latches, and restraint hardware should be standardized and use off-the-shelf hard- ware adapted to meet spacecraft maintenance re- quirements, if necessary. • Use standard Allen-head type drive tools, where possihle, to release latching fasteners. 2-74 I 2.2.1,5 Materials S~lected msterials used to fahric8te the Multiple DDcking Adapter are discuGsed in this sectt~n. including metallic as well as non-metallic materials; the design requirements; test- ing and. conclusions and recommendations based on l1DA experience for future manned opace programo. A complete listing of all materials used 0n the MDA can be found in Report ED 2002-2021- 11 Rev. A. A. ,\leCa1s - ~leta18 used in the fabrication of the MDA included t~e follOWing alloys: • Aluminum - 2014, 2219, 2024, 6061 and 7075 • Steels - A286, 300 Seri- J Stainless, l7-4PH, l7-7PH, PH15-7 Mo and MP-35N. The basic structural shell of the MDA was designed and fabricated by NASA-MSFC from 22l9-T87 aluminum alloy. (See Section 2.2.1.2 for details). (1) Requirements - The requirements for the selection of metals by MMC for the MDA installations was based on the optimum inter-relationship of per- formance, cost, availability and reliability. One of the prime concerns t~as stress corroaion crack- ing. The initial controlling document "as MMC drawing 82000000205, "Design Criteria - Material, Processes and Finishes". Later in the program MSFC document lOH33107, "Guidelines for Con- trolling :ltress Corrosion Cracking", "as imposed. (2) Test - No element testa t-lere conducted on the MDA program. Strength allowablea ~lere taken from MIL-HDBK-SA. Teat bars Were processed with parts for tn-plant heat treatment as required by Standard Processes. (3) Discuapion - Parts were designed in accordance wi th Ml1C drawing 82000()0020S to preclude the possibility of otreos corrosion cracking. This dra"ing defined the ma:dmum allot-lable stress as a perclstage of tensile yield strength for each alloy and temper and for the longitudinal, long transv'erse and short transverse that cannot be exceeded. Table 2.2.1-3 shows the allowable stress 2-75 ,-- --- ---------'-.,-- . _- .. I _. ~!-J...QI:IABLE STRE"'p_: % Fty .ALLOY , TEMPER FORM -1 LONG - r' SHORT - I (Bare or Iridited) LONGITUDINAL TRANSVERSE I TRANSVERSE . .. - .. -.- '-~--- -.-.•. --- . ---_.----- --------- ----~- 201.4 -Ttl, T62, Plate 70 50 15 -Tu51 !opediEt:awll:_ Bar AL ~T6, . -f62';- . . - . -- --- .- _ . . -- - . .. .. T6510 Extruded Bar 70 35 15 __ -T6511 .....,._ -.----.-.. - - -"-'-''''- -- .. .. 35---' 1-- '1'5 -T6, -T62. FO'.ged Bar 50 -T652 I --- ~T3, T351, r--·-----.. -- ------ .-.----_.- - i---.. - . ... 70 50 15 I 2024 -T4, T42 Sheet, Plate AL -T351, 70 50 15 -T3511, Rolled/Drawn Bar, -T42 Extrusion -------. - ':T6i,.:TSl -----. .. - -.. -. ... - --- ---- ---- -.. - - ._------2219 -T87 Pl.ate 75 75 75 /"..L -T62,-T81 Rolled/Drawn Bar, -T87 Extrusion 75 75 75 -- -- . - -1:6, -T62 - .---- - .... ,... ... __ ._-- - ---_.- ~ :~::~,,2' Plate 100 100 100 ---'- --- - --'. .- . - -r-- .- ----_._- .. 6061 Rolled/Drawn Bar 100 100 100 AL -T6, -T62 , -_ .. -- - ----- .. _- . _- - . - _0. . -- -T6510 Extruslon 100 100 100 -T65ll .. - -- .. _. -- ... _.,-- --_ .. -._- - . - - - ........ -_._-- ._-- - -T6,. -T62, Plate 75 70 12 7075 I- -T651 .. -----.--- _ ... p--- -0_-__ - . ... ~--' ,---AL -T6, -T62 Rolled/Drawn Bar 75 70 20 -T651 -T6, -T62 --'- - -T6510, Extrusion 75 ' 50 12 -T6511 -- --- -- ._----_ .. _-. .•.... ------ -- - ... -- 300 "re" ",., .~r"'" n., 100 100 100 - -.- ...... _.- --.. ..- --.--- ._.... -----._--_ .. ---- 400 Series Steel Plate & Bar 30 30 30 -_ ...... -_. .-- -- - - .. - _._ ............ - 17-4PH Steel Plate & Bar 75 75 75 _._-_ .. ._--_ .. - PH15-7MO Steel Plate & Bar 50 50 r._': -j A-286 plate & Bar 100 100 ---- -------.. _._-_. MP-35N Bar 100 100 100 .. .. ---_ .. _-- Table 2.2.1-3 Resistance of Metals to Stress Corrosion Cracking 1. ~ " n ·"II~,-. "-'''--''-1-' reduction factors used in the MIlA design. These values were conservative and wel:e baaed on test data from various aource~. Additional steps that were also taken to minimize atreas corrosion cracking were: • Use of stress relieved tempers where posGible. • Use of chemical filma. organic coatings and aealants. • Avoiding interference fits on installation. • Shim where required to minimize bending. • Avoiding galvanic couples. • Improving the surface by reducing surface roughness or increasing surface compressive stresses. }!SFC drawing 10M33107. "Guidelines for Controll- ing Stress Corroison Cracking" was imposed later in the program. A survey of all MDA structure was made and a total of 42 critical structural items made from 2014 or 2024 alloy were identified as susceptible to stress corrosion cracking. In accordanca with the requirements of 10M33107. a Stress Corrosion Evslustion Form wss preps red for esch item. These evaluations took into account the alloy, temper, size and form, residual stress, assembly stress, finishes, function and rationale. They were submitted for approvsl to MSFC. Steel alloys were used I'ri~' 'tv in mechanical fasteners and mechanisms wh, high strength was required. Steels used Were A286, Tensilized A286, 300 Series Stainless, 17-4PH, 17-7PH, and PH1S-7 Mo. To minimize stress corro.ion cracking, the precipation hardened steels were used in the following heat treat conditions: AlloY H.T. Condition 17-4 PH HI02S 17-7 PH CH900 PHIS-7 Mo THIOSO 2-77 '-'-"-' -'.", , i All steel parts were passivated after final fabrication to further reduce any tendency for corrosion. Multiphase MP-35N was used on the MDA where extremely high strength was required. This nickel-cobalt ba~e slloy was hardened to strength levels of 260-300 Kai by work strengthen- ing and aging. Thio ~lloy had excellent resistsnce to corrosion and stress corrosion ~racking. (4) Conclusions - AVoid, Hhere possible, all alloys known to be susceptible to stress corrosion cracking. "here this is not possible, use allowable stress reduction factors, coatings, sealants, shimming and stress-relieved tempers. B. Nonmetallic Materials - (1) Flammability, Odor, Offgass~ng and Vacuum Out- gassing (a) Requirements - The flammability, odor, off- gassing, and VRCUum outgassing requirements for nonmetallic materials used on the MDA were defined in the following documents: • 5OM02442 - This document, i,'sued by NASA! MSFC, defined the vacuum outgassing requirements of high vapor pressure materials on the eltterior surface of the MDA in line-of-sight with critical optical surfaces. This requirement was intended to control the deposition of contamination on these surfaces result- ing from outgassing of materials from other surfaces. • MSFC-SPEC-10lA - This document defined the flammability, odor and offgassing requirements fOl' materials within the MDA. The requirement for offgassing in this case was concerned with the carbon monoxide and total organics given off by no~etallic materials when heated to 155 F in a 5 psia oxygen atmosphere. I 2-78 '. . ... 1'.-- (b) Tests ~ All materials used "ithin the MDA \~ere teG'."d for flanmm'>ility, odor, and off- gaosing of carbon mono:dde and total organics unleos rationale for not teoting could be provided on the baoia of similarity to materials or configurations already tested. ~ll materialo used external to the MDA in Gignificant quantitiee ond in line of sight \~ith critical optical surfaces were tested for vacuum outgassing to the requirements of MSFC Specification 5OM02442 unless rationale for not testing could be provideu on the basis of similarity to mate.'iela already teoted. Results of these tests are summarized in 5OM02442. (c) DiscUBsion - Final acceptability of non- metallic materialo to the requirements of MSFC-~PEC-10LA and 50M02442 WBS based on the m·~ll.ner in which the materials were used relative to one another, ignition sources, hest sinka, flame barriers, flame enclosures, etc. Therefore, use of all nonmetallic materialo was documented in numerous usage "greementa \~hich were submi tted to NASA/>1SFC fIJr approval. The usage agreements descl'ibed each application in which nonmetallic materials were Lsed, and listed the quantity (weight end oxposed surface area) in thd particular application. They alao included the test data which supported the acceptability of the materials as 11el t ae the rationale justifying their ~cceptability. The usage agreeml1nt, when approved by the Hateriala Branch of }!SFC, ~las then submitted to the Materials Applications Evaluatioll Board for final approval. The complete lis. of nonmetallic materiala used by MMC in the MDA, together with a deBc~iption of the appli~ation8, the quantity used, and the applicable usage agreement number is given in "}1ultiple Docking Adapter Materials Flammability, Odor, and TOJ~ 9nd requireJ for latching arplications at time of launch. All Astrovelcro tested met the shear and tension criteria. (c) Discussion - The H549 hook and P537 pile used by MMC on the MDA were selected because of their demonstrated resistance to flame propagation. They also met the necessary odor and outgassing requirements. However, they had relatively low peel strength and were easily damsged by abuae, such uS machine sewing; second, the did not have long durability, even under ideal conditions. Tests with Astrovelcro sewn to Beta cloth showed that the use of pieces smaller than 1" x 1" was undeSirabll! and that the practice of crose-stitching was elso undesireble because the stitching inter-· fered with the effectiveness of the hooks and loops in latching together. It also con- tributed to hook damage caused by ~he sewing machine foot. 2-90 I I I Although no problems "ith Astrovelcro were eJtperienced in the MDA. in Oecember 1972 it "as discovered that the Astrovelcro used in the Flight Biomedical Stowage Container in the OWS had poor latching capability. Close examination of the hook tape revealed that many of the hooks appeared to have "straightened out". a high percentage of loops were uncut. and loos of hooks was alao observed. This material hsd been attached to straps in the stowage containers by machine sewing. using cross-stitiching. and had been exercised many times. The hooks in the H549 hook tape are made by cutting loops of filament that are woven into the tape and held in place by the fluo,el backing. The lot of tape used in the Biomedical Stowage Container was generally less stiff than any of the other lots of material examined due to smaller thickness of fluorel backing. It ia possible that this contributed to the large number of uncut loops. Examination of unused material from the lot used in the Biomedical Container showed that there were 17 percent uncut loops. As a result of these observations and discusaions with the manufscturer of the material. a maximum value of 15 percent of uncut loops was established as the sccep- . table criterion. (d) Conclusions - Experience with Aetrovelcro in the MIlA uas led to the following conclusions. • Astrovelcro hook and pile tape installed in the MDA for restraint applications during launch and for astronaut aids were Batiofactory. • Fu~ure design applications should be made conaistent with the following general recommendations. - Minimum size of pieces of Astrovelcro hook and pile should be 1" x 1". 2-91 "I • Astrovelcro hook and pile tape should not be cut lengthwise. Cross-stitching should never be used for attaching Astrovelcro hook and pile. - Where conditions permit, adhesive bonding should be used for attaching Aatrovelcro hook and pile. - Astrovelcro hook and pile tape should not be uaed in high-use critical latching applications. (6) Paint Systems Used on MDA - The interior and exterior paints were primarily polyurethanes. (a) Requirements - The selection of paint systems for the MDA was baaed on the following requirements. • Good abrasion and wear resistance. • Ability to meet the total organics, carbon monoxide and odor requirements of MSFC- SPEC lOlA for interior use. • Ability to meet the vacuum outgassing requirements of SOM02442. • Ability to meet the thermal control requirements and temperature extremes externally. (b) Test - The following tests were conducted on paint systems. • Interior Usage - Total organic, carbon monoxide and odor teats were conducted per MSFC SPEC lOlA. It wss determined from these tests that an elevated temperatfire bake cycle was required to meet the requirements. As a result, two bake cycles were used on the MDA depending on the configuration. 1 I ) • ~xterior Usage - Tests were conducted for vacuum outgassing products per 5OM02552. It was determined that a one hour bake st 3250 F enabled the paint systelT. to meet the criteria. MHC slso conducted a series of thermal shock tests to determine what effects, if any, would occur to the external paint system when exposed to the MDA oIbital environment. After 20 cycles, the panels were removed from the chamber and visually examined. No flak- ing cracking or degradation was evident. (c) Discussion - The interior polyurethane paint system with the prescribed bake cycle held up extremely well. It provided a hard, durable =inish for the inside of the MDA. The paint systems used on the MDA exterior and tested on this program were: • Laminar X500 Polyuret~ane, Black, Dexter- Midland 4-B-33: MHC SPEC. STM-K738. • "Nextel" Polyester Coating, Black, 3M 401- C10; MHC SPEC. STM-K760. • Silicone Thermal Control Coating, White, Dow Corning 92-007; MHC SPEC. STM-K728. The black polyurethane laminar XSOO paint system was used on most of the exterior of the MDA and represents approximstely 95 percent of the paint. The "Nextel" poly- eater black coating was used around the 8-190 window where minimum reflectance was required and represents approximately two percent of the paint. The 01licone white coating was used as a visual docking aid around the conel, barrel junction and represents about three percent of the exterior paint. i, ..;.. , I , I , , The three paint systems used on the exterior of the MDA showed no flaking, :6Bcking or degradation when exposed to 10 torr vacuum and cycled between +275 and -lB~ F for 20 cycles at 90 minutes per cycle. A problem with paint adhesion occurred on stainless steel parts, especially the liner in the radial docking port. A phosphoric acid etch of the stainless steel ~ave eatiafactory adhesion results. (d) Conclusions - Experience with paint systems 011 the MDA has led to the following conclusions. • Polyurethane paint system performed well on the MDA during the mission. • Almost all organic type coat :.ugs require an elevated temperature balte cycle to meet total organic, carbon monoxide, odor and outgassing requirements. • Polyurethane paint systems showed no degradation due to thermal cycling from -lBO to +2750 F. (7) Electrical Wire and Cable Flammability Protection System (a) Requirements - The basic requirement for the electrical wire and cable flammability protection system was that the installed aystem shall meet the flammability, odor and offgassing requirements of MSFC-SPEC- lOlA. The installed wire and cable system shall not propagate a fire when exposed to an external ignition source, nor when the wire is tested for electrical overlsod to the point of malting the wire. It was also considered highly desirable that the flammability protection system be such that changes could be conveniently made in the wire bundles and routing of harnesses after installation. This obviated the use of any type of rigid conduit made of metal or other nonflammable material. 2-94 (b) Test - '=he basic UDA wire harness configuration, including the flammability protection system, was tested for overload snd external ignition to the n'!111 ~a".'~nto of MSFC-SPEC-IOlA in 100% oxygen at 6.2 psia pressure. The con- figuration met the requirements (Ref. NASA letter - S&E-ASTN-MX-MCAu 70-12, 2 October 1970, and PM~SL·AL/MDA (494-71), 30 March 1971). All materials have also been tested to the odor and toxicity requirements of MSFC- SPEC-lOlA, and those used in significant quantities have met the requirements. (c) Discussion - The basic wire alld cable configuration consiated of aingle and multipe conductor silver plated copper wire, insulated with PTFE and a polyimide coating. Multiple conductor shielded constructions had a fluorinated ethy1ene- propylene (FEP) copolymer jacket over the shield. Flammability protection was provided by a continuous fire barrier from connector to c~nnector, and consisted of a r.ombination of lengths of Bentley-Harris Type 66LWA f1uore1astomer-coated fiberglass tubing. Continuity of the tubing was accomplished by mea us of butt-joints covered with additional' lengths of the next larger size tubing to provide a two-inch overlap on each side of the splice. The tubing was tied in place with Bentley- Harrig Pyrolace STVR, a f1uoroelastomer coated fiberglass lacing tape. Terminations into connectors were covered as follows: • ?Dro-G type connectors were covered by Raychem NBG f1uoroelastomer convoluted tubing and boots. Thia material was qualified to MSFC-SPEC-10lA by MDAC-West. e Other connectors were covered by Beta bags (See Section 2.2.4). A Beta bag was essentially a sleeve made from a double layer of PTFE-coated Beta-glass cloth. A length of Bentley-Harris Pyro1ace STVR lacing tape was sewn into each open end of the sleeve to provide the capability of pulling and holding the ends of the i II~ ___ ~-~ sleeve snugl)' in place, one end around the connector, and the other end around the sleeving that covers the wire or cable. Thus if the nonmetallic insert in the rear of the connector ignited dUA to a shortMcircuit or overload, the flame would be held '~ithin the bag, and would be extinguished due to lack of Olcygen. (d) Conclusions - Experience with the flammability protection system has led tb the following conclusions. c The MDA electrical wire and cable system, in conjunction with the flammability protection system, met the flammability, odor, and offgassing requirements of MSFC-SPEC-101A. • The uae of BentleyMHarris Type 66LWA fluoroelastomer-coated fiberglass sleeving in conjunction with Beta bags to cover connectors proved to be a con- venient, flexible technique for p~oviding flammabilit) protection to electrical wire and cable systems. . C. ATM C&D/EREP Coolant Loop Contamination - (1) Requirementa - The deaign requirements for the ATM C&D/EREP Coolant Loop are discussed ill. Section 2.2.2.2. This section of the report is concerned with the Materials Engineering requirements relating to corrosion of the metallic components, the formation of pre- cipitates in the coolant and the possible problems of c.oolant loop leakage and filter clogging. The coolant loop consisted of a combination of stainless steel and various aluminum alloys. This hetelDgenecus combination resulted from the need to use already-developed hardware. The ATM C&D Console was originally intended to be used in the 1M in conjunction with the wet workshop concept, using ethylene glycol as the coolant. Aluminum was selected for j. ~I Ii i' Ii f [I " 1,1 , this application. The pump had originally been developed for the suit cooling loop, for which a stainless steel aystem ,qes used. When the decision was made to UBe the dry workshop and move the ATM C&D Con~ole into the MDA, the result was a coolant loop containing a combination of stainless steel and aluminum. HDAC developed an inhibited coolant to preclude corrosion within the system. The bSBic requirement for the syatem was that it continue to oper~te throughout the Skylab mission, ~7ithout leakage or ell '8S- sive filter clogging. (2) Test - The followintl tests lqere perfor.ned to determine if galvanic corrosion of metal components in the systeM could be a significant problem: • Corrosion rate of aluminum alloy (6061-T6) when coupled directly with stainless steel (304) in the coolant. • Assessment of corrosion for simulated tubing arrangements representing coolant loop configuration and consisting of aluminum tubing, aluminum Voi Shan washers. nickel Voi Shan washers. stainless unions, etc. • Co:rosion rate of aluminum~stainless couples a8 a function of coolant pH. ing was conducted over a pH range of 11. ateel Teat- S to Tests were conducted to evaluate the effect of current flow through various configurations of ~tainless steel-aluminum alloy joints immeraed in the coolant. Teats were also conducted to determine the effect of elevated temperature on corrosion rate, the effect of dissolved oxygen on corrosion rate. and the effect of applied potential on current density at the 6061 aluminum electrode in the coolant. 2-97 .... I I ~ I, I, [' , , j, Resu1co of the tooting program indicated that exceosive corrocion did not ')ccur under the conditiono ,·f teot, but: corrosion rates did increaoe at higher pH values and at elevated temperature, aD \·,,,11 00 \~:I.th oxygen in the linea. These reaulto ~hol'led that corrosion should not be e problem, cince the coolant nOrlrullly operateD at rolatively lo~' temperatures (490 _7Sop), io deoernted before being out into the oyaC"m ond 10 buffered to keep the pH ot 9.1 to 9.5. It 1'100 0100 learned from the testo that the f1011 of current across a atainleoo steelaalumioum joint in contact I~ith the coolant could caUlle >::he aluminum to react if the "loctrical roaistance were high. Again, Ceo~o ohowed that the electrical resistance bet~7eon stainless Dteel and aluminum in the MDA coolant loop I'II1S negligible, DO that cher" ~lould be no reaction resulting from this ceuoe. Analysis of the basic coolant solution indicated that ito chemical formulation WII9 ",ceptable lind that performance should be sDt~sfactory for t.~e life of the miElsion. (3) Discussion - The coolant loop pumps in the Airlock l·lodule I~ere protected by a 25 micron absolute filter located just downstream of the MIIII-A!·! interface. While servicing the system in January 1973, a blue millipore separator paper l~all impropr.rly used in a millipore filter aooembly located in the GSE oervicing system, in plece of the millipore filter paper itaelf. The eeparator paper tore during loading before the error was identified. The separator paper was removed and replaced with a millipore filter paper serviCing continued. After the system had been Circulated, it WSD decided to remove the system filter and examine it for blue fibers from the separator paper. Filter #1 was thus removed from l:he flight .unit coolant loop following testing correoponding to appro,ximately one year of service and filter #2 was installed. Examination of filter #1 showed a few blue fibero but th,~ filter was relatively clean. (4) i Filter #2 wos installed on February 1, 1973. During operation of the coolant loop, the accumulator bladder in the Al1 ruptured (approximately 15 February) causing the pumps to cavitate. Soon after replacing the bladder, ~IDAC observec increasing pressure a.;:ross the filter and suspected that fragments of the bladder material may have been responsible. Upon removing the filter, it Has observed that SO percent of the filter surface area ~las covered I~ith Nhi te to gray res idue • Analysis of the residue indicated that it contained approximately 14 percent by weight of aLuminum. This raised the question as to I~hether or not rapid corrosion of aluminum tubing in the An! or EMP cooling system had occurred. Results of examinations of filters used in the coolant loop from January 13, 1972 through the SLwl/2 mission disclosed the following information: Filter Installed January 13, 1972 February 1, 1973 Harch 12, 1973 Harch 26, 1973 April 12. 1972 May 28, 1973 (SL-l/2 Hiss ion) June 14, 1973 (SL-l/2 Hission) Filter Removed January 20, 1973 t·larch 6, 1973 Narch26, 1973 April 12. 1973 Hay 28, 1973 (SL-l/2 Hiss ion) June 14, 1973 (SL-1/2 Mission) Sept. 23, 1973 Filter Contamination Insignificant Contaminated Insignificant Insignificant Hoderate Insignificsnt Insignificant Filters returned from SL-3 and SL-4 likewise showed insignificant contamination. This investigation indicated that the contamination formation was peculiar to oparation of the coolant system between February 1, 1973, and Harch 6, 1973. Concluoions - Experience l'lith the A'lM C&D/EREP coolant loop led to the follOWing conclusions with respect to contamination. 2-99 ,.,~ I ~-= -'f' ~~,_= ____ >_~._. _____ ~_ ·--------r i (a) The primary concern that coolant loop system leakage could occur through corrosion effects is not a problem. No leakage occurred in orbit on the inhibited water side (A~ C&D/EREP side) of the system. (b) The secondary concern that clogging of the system filter could occur is not a problem since analysis of the two filters removed during the first mission and one removed during the second mission indicated only a moderate buildup of particles on the first filter and an insignificant buildup on the other two filters. 2.2.1.6 Mockups and Trainers A. MDA Zero-G Article (1) Design Requirements - The design of the Zero-G Article was constrained by the size of the KC135 aircraft and a regulation crash load factor of 6 g's. The equipment ,~as to be designed free of sharp edges and sized, shaped and located to correspond to tent- ative flight article design. The equipment was to be evaluated under Zero-G conditions in an effort to satisfy component design, crew work envelopes, re- straint and translation requirements. (2) Description - The MDA Zero-G test article consisted of a one-eighth segment of the MDA inner ,hell mounted to a support base structure (Figure 2.2.1-12). At- tached to the sheli were five separate packages of flight test hardware: (a) ATM C&D Console Crew Station (b) Film Vaults (c) Initial Entry Package (d) Experiment Package (e) Service The test packages, mounted {nside the KC135 aircraft, were subject to a number of parabolic Zero-G maneuvers. Two test personnel checked and operated the equipment, and their actions were to be evaluated by an astronaut for 30 seconds of each maneuver. All the equipment was mechanically functional to the extent that it satisfied the design requirements. (3) Test - A test procedure was written for each of the five test packages. The test subjects and evaluator averaged 2.5 hours of flight time and 40 parabolic Zero-G maneuvers of \.esting and evaluation on each pack- age. Component design work envelopes, restraints, mechan- ical equipment operations and translation devices were evaluated on all described hardware in accordance with design requiremen~s. (4) Test Results - All equipment perfort"ed according to plan. \~ork envelopes were established for the ATM C&D console, film vaults, initial entry pr activation tasks, and for the operations of the M5l2 and S009 experiments. 2-101 Restraint platforms at the ATM C&D and the MSl2 work station were verified for flight use ",ith re- quirements [or improvements identified in posicion- ing and markings. Handholds and handrails were fixed for the MDA at all work stations. Improvements were recommended in the area of pressure hatch stowage re- tention, fan removal and replacement, and retention pins for film vault doors and cameras. Lastly, re- locat ion of ECS fle" duct stowage was suggested [or flight design. Figure 2.2.1-12 Zero-G Trainer 2-1D2 (5) Conclusions - Generally, this I~as a succesaL'.1i. l'~v gram. The Zero-G Trainer did not faithfully repre- sent final design configuration in some instances, because it was delivered while the }IDA I~as in an early design phas". RO\~ever, the tests were valuable in establishing ground rules for design and resulted in a vehicle that functioned successfully in orbit. From the }IDA Zero-G test program results, a similar program is recommended to develop and verify the de- sign of future manned spacecraft. B. }IDA Neutral Buoyancy (NIB) Article (1) Design Requirements - The NIB Article I~as designed for long-duration water immersion ir, a 40-foot-deep NIB Simulator facility located at MSFC. The article I~as to be used by astronauts and engineers to study and test MDA equipment and for performing crel~ activ- ities in a neutrally buoyant environment free of sharp edges and corners. Equipment was to be attached in a manner to permit installation and removal under I~ater by qualified personnel. (2) Description - The NIB Article consisted of a full- scale "I~ire mesh" structure of the MDA configura cion including a radial and axial docking port (Figure 2.2.1-13). The interior and exterior Iqere outfitted with envelope-type mockups for stationary equipment and neutrally buoyant mockups of equipment that was required to be moved during the underlqater tests. Certain loose equipment was foam filled to achieve neutral buoyancy. The equipment had special paint finishes and metals to meet Iqater contamination and materials corrosion requirements. The NIB article was deSigned to be used for the initial verification of equipment location, crew training (or task verification), and for mission support. The initial article I~as delivered early in the program, and many modifications Iqere added after the a.'ticle was installed in the 11ater. (3) Test - Intravehicular (IVA) tests included activa- tion exercises of probe and drogue removal and stow- age, pressure hatch opening and stowage, electrical and communications umbilical hool(up, flex duct hool(- up and vent sealing. IVA tests further included work station envelope checks using restraints 10- 2-103 ._ .. ..... _-_ .. '- Figure 2.2.1-13 Neutral Buoyancy Article cated at the ATM C&D, film vaults, EREP C&D and MS12 work .tations. Envelope structures of other MDA equipment permitted effective IVA evaluation of total work space and translation of equipment to and from stowage containers. Film vault doors and con- tainers permitted checking constrained door swing envelopes, and vau1.t contents could be removed t o test installation of equipment on the cassette trees and translation through the MDA and the AM. EVA test procedures for the most part included trans- lating cameras and canisters from the MDA through the Airlock to the ATM Sun Shade. Later program develop- ments included a test to determine procedures for re- leasing a jammed 51 91 door and checkout of an 5190 window cover contingency operation. 2- 104 • ~I (4)·· Test Results " All of the equipment performed to the satisfaction of the crew and their tcst rcquirements. ND.<\ I~ork statim, envelopes I~ere verifiod for flight design. A 10cat1ull for launch and stOl~ago of the C3rnera trees I~ere established for flight article de" sign. (5) Conclusions - Thc fidel:!.ty of the installations was periodically updated as equipment configurations wero firmed up. Some of tho neutral buoyancy train" ing was thus conducted using out"of"dato designs. 1I00~ever. the test artiele 1~3S g(lnerally successful in meetin[l the deSign requirements. A similar pro" gram is strongly recommended for future manned spacecraft. C. ~!DA Engineerin[l }!ockup (mru) (1) Design Requirements - The E}ru shell I~as furnished GFl', to bo" structurally refurbished by }IHC to the latest configuration of the }!DA. It 1~3S to be out- fittod and upd3ted I~ith Iqith mockups of equipment for incremental "Crelq Revimqs" and a final "Critical Design Reviel~" • (2) Descriptiol1. - 'rhe E}ru I~as 3 stt"Ucture similar in ap- pearance to the }!DA Flight Article. It I~as simpler in construction thar. the Flight Article, consisting of a mechanically fastened shell structure complete Idth doctting ports, l~indOlq, 10ngerons, frames and component supports. It was provisioned primarily Iqith mocltups of internal components, mostly I~ood, and Iqns used to tentatively verify component design, physical interfaces and component: placemont. The m!U I~as functional to the extent that it satis- fied coordination betlmen onr,ineering design and Cl"eW opel'stions persomlel in locating equipment. Each n(!\~ pieco of equipment Iqas mocked up, located in the vehicle and reviC\~ed by a crel~ rnembet'. This resulted in conntant change and therefore most of the equipment I~as of 10\~ fidelity envelope con~ struction. As the mru program canlO closer to its end~ the mocttupwas updated to r(!£1ect late design 2.-105 • .. changes, and the fidelity of some mockup components 1~0r, improved. Thus, for tho fin01 GDR the accuracy of rml1 hardware l~aS significont1y better than Zero-G "',:ticle componentG. (3) TL'ot - Testn on the mru are better described as cr01~ revicws. No procedures l~ere l~ritt6h lor these re- viel~s. Five incremental crCl~ revielJs l~ere conducted on the engineering mockup over a six-month period culminating in a final CDR. A crel~ reviCl1 consisted of on astronaut I s evaluation of the latest E~ru configur ation of the ~IDA. It enabled the desIgner to proceed l~ith flight article layouts and equipment drmqings and permitted definition of physical interfaces. The CDR I~as the final reviCl~ of the mru, which brought customer and contracto. engineering and crew personnel together for a final decision on the hasic ~IDA con- figuration. The CDR allolJed the designers to proceed with the design and release of flight article equip- ment drawings for fabrication and tests. (4) Test Results - The E~ru performed to the satisfaction of engineering and crew personnel. Crew reviel~s of the equipment 11ere carried out according to plan. Thc CDR went according to plan and a minimum numher of Reviel~ Item Discrepancies (RIDs) I~ere dis- positioned. Flight Article desJ.gn was al101~ed to proceed according to schedule. (5) Conclusion - The CDR I~as the first opportunity for physical interface fit checks of GFP equipment in the ~IDA. This included the interfaces betNeen cameras and film vS\Ilts and cassette trees l~ith ~IDA support structure. The mru tests resulted in the conclusion that it l~as a most successful program. The moclmp served its intended purpose as an engineer/areH interface tool for the integration of the ~IDA equipl'mnt. A logical recommendation would be that an mru is neceGsary for the development of manned spacecraft. 2-106 D. MDA One-G Trainer (1) (2) _ (3) Design Requirements - The One-G Trainer Ivas required to accurately reprcoent the NDA for purposes of cr(>w training_ As the trainer waD to be developed from the engineering moclmp, no baoic structural require- ments Ivere specified other than handling and trans- portation loads for movement of the trainer from Denver to JSG. Dimensional .tolerances, processes and materials selection requirements tvere not stl'ingent, as long as appearance and functional training values llCre not adversely affected_ Description - The One-G Trainer lvas converted from the EMU. Structural revisions made to the shell per- mitted handling for hOl'bontal and vertical training positions. The fidelity of its equipment was improved so the trainer was mechanically accurate and also in- cluded some electrical systems. This included a com- plete set of "flight-type" electrical cable trays and equipment support structures. A mod kit program kept the One-G Trainer updated lv1th current flight hardtvare changes after delivery to JSG for crelV training. Test - The One-G Trainer was provided for the purpose of familiarizing the astronaut I;ith the ~mA and its related equipment. It was further used for thb de- velopment of crelV (on-orbit) operations and pro- cedures. TlVo types of hardware were used during astronaut training; i.e., Flight-Type Training Uard- l;are (FTTU), and Hockup-Type Training lIardlVare (/>ruTU). MUTH was used for HDA mOdule training and FTTU was used for HDA eqUipment bench training. Training was separated into tasl,s using procedures such as inflight msintenan~e, activation and deactiva- don. This necessitated the use of both FTTU and MOTH. After fsmiliarization I~ith module and bench hardware and procedures was apparent, training I~as extended to the total Skylab cluster in l~hat was called a ''Hini- Sim". "Hini-Sim" was an incegrated Skylab One-G training program for a specified number of days. Three astronaut crewmen simulated on-~rbit tasks and proced- ures for the total Skylab mission. 2 .. 107 . . .-- (4) Test Results - The tmA Ontl-G Trainer I~as a most Qucceas- ful piece of hardware. It permitted the integrat ion of man l~ith machine, fr.-om ,~hich procedures I~ere developed that I,;ere used for ~IDA Flight Article crew/hardware op- erations. (5) Conclusions - The timeliness, quality and cost effective- ness of the ~IDA One-G Trainer I~US most apparent to the Skylab astronauts, Alan Dean, SL-3 Commander, has spe- cifically cited the excellence of One-G training hard- ware as a key to the success of Sltylab missions. Especially evident l~a8 trainer hard,qare use and effect- iveness in solving Skylab contingencies encountered during the mission. A One-G Trainer is necessary for the familiarization with hardware on "on-orbit" crCl~ procedures of future manned spacecraft systems. 2.2.1.7 Mass Properties A. ~IDA ~mss Properties Program - During the three-year period from ~my 1970 until launch on Nay 14, 1973, ~l}!C conducted an active mass properties program and issued monthly status reports. These activities included weighing of the ~IDA structural shell upon re- ceipt from NSFC, calculation and weighing of components during de- sign and build, weighing of the 'MIlA when it was moved to the NNC High Bay Clean Room and upon delivery to 1:IDAC at St. Louis, follO\~cd by continual tracking of I~eight of new equipment instal1ations up to launch. . Launch weight of the 'MIlA was 13,650 pounds. One of the first recorded bIDA Weight estimates was 8,819 poullds in October 1969. The first 'MMC ~IDA status report of blny'1970 shol~s the blDA had grown to 10,934 pounds, including EREP. These three I~cight numhers will be key to the discussion of weight grOl~th presented below. The following paragraphs will discuss blDA weight growth history and control with cmphllsis on those itemswltich caused unexpected weight growth. Where possible, data I~ill be presonted sholdng the reasons for growth along ,qith analySis of the final weights alld re- lated design factors to provide basis for future weight estimates. In this discussion the following mass properties definil:ions I~ill apply. . 2w.108 B. Definition:! (1) Control Weight - A mUltimum ullo~Jable Height Hhich is allocated by the customer and derived from booster payload capability. (2) Current ~7eight - Represents the current design informa- tion available at any point during design or develop- ment. (3) Margin - The difference bett.een control t1eight and current ~7eight. (4) fuse line Height Estimate - The weight estimate based upon the design concept at some defined point in the designing process. (5) Weight Grot.th - The increase in vehicle Height i:rom baseline weight estimate. Growth is of t~70 types; i.e., Mission Requirement Changes, and Design Process Changes. (6) Mission Requirements Changes - These are additions to the requirements of the baseline definition made de- liberately to increase vehicle utility and take full advantage of booster capability. (7) Dc~ign Process Changes - As design and fabrication of a vehicle progresses, current weight will reflect re- finements of the design within the concept of the initial definition. (8) Contingency - Weight allowance added to a weight estimate (usually a percentage based upon past ex- perience) to project a final vehicle weight. C. Growth Rate History - A detailed study was conducted' to evaluate the Sltylab weight growth. In this study, the concept of Mission ReqUirements Changes and Design Process Changes was ex- l'lored in depth. Results of this study, as it applies to the MDA, are shown in Figure 2.2.1-14. T 'Itr;1 . ' +50 ...,+40 c OJ u ~ l!:i+30 .c ~+20 ~ . '0" =<:5. ~.--------(~~ .... . ~~ 60 :;:: t: ." successfully' passed the tests. (c) Acceptance Test - The assemblies are verified to be built in accordance "'ith the engineering drm1ings. Their installation in tile }IDA is verified by a fit check l1Uh a Government Furnished Equipment (GFE) fan assembly. (3) Diffuser, MMC PIN 82000001720 (0) Development Test w Devr 10pment tests were COll"U'1 ted to verify the capabil ity of the diffuser to provide the required distribution of a il' flo,~ in the MDA. This r"4uirement specitied that the air velocity range at the MDA crew work stotions be between 15 to 100 FPM. Initial testing of the diffuser was conducted by MSFC. Flow tests wel'e run at 5 psia and at 14.7 psia. Based on the test results, it was recommended that an Anemostat Corporation, type C-2, five inch neck diameter or an equiva- lent diffuser be used for the MDA. The Anemo- stat diffuser was used, as reconunended, though modified to conform to structural and human engineering design raquirements. A system air distribution test was conducted by MMC. A mocl,up of the CSM. STS and the A}! ,~ere mated with the engineering mockup of the MDA. The MDA and the STS were outfitted with the best available fidelity of internal hard- ware and expel'iment packages. The diffusers were installed and positioned as for the flight configuration. A ma~ping of the air velocity profile within the hJA/STS was made. The distribution chal'Bcteriqtics were determined by observa tion of smol,e cloud dispersion and by taking velocity measurements. The test results verified the system capability to maintain the air velocity requirements at the Cl'e,~ s ta tions. A development test was conducted to demonstl'ate the capability of the diffuser control bridge 'to withstand design yield and ultimate s,tress loads. Torque loads, providing equivalent design stress loads, were applied to the diffuser control !~nob. The diffuser Buccessfully passed the tests. The diffuser was mechanirally func- tional even after being subjected to ultimate stress loading. --. - .. ----~------; }: (b) Qualification Test - MMC, Report No. 3184 - The qualification testing. of the diffuser l~an COllducted by NNC. The qualification tests consisted of a performance test, a sinusoidal evaluation test, a vehicle dynamics low frequency sinusoidal test, a high level random vibration test, and a lOI~ level random vibration test. The performance test was conducted prior to and after the diffuser was tested in each axis of vibration. The performance test procedure was a manual adjustp1ent of the control ltnob from one extreme position to the other. A mechanical failure of the diffuser occurred during the high level random vibration tests. A failure analysis disclosed that the structural support hangers for the n,~ "Jable COlle of the diffuser slipped out of their installed position. The analysis is presented in Failure Analysis Report no. B6741S. A modification "Was made to the diffuser in which the hangers of the movable cone were welded to the interfacing detail part to form an integral assembly. A complete retest of the diffuser was conducted without any sub- sequent failures. Refer to MMC Report No. 3184 for the qualification test data. (c) Acceptance Test - Acceptance test requirements for the diffuser l~ere speCified in the 82000001720 MMC engineering drawing. The test consisted of a verification of the number of turns of the diffuser control knob required to move the movable cone from one extreme position to the other. This adjustment of the movable cone verified that sufficient movement of the cone was available to change the air flow pattern. (4) Fan Shroud Assembly MSFC PiN 20N42270 (a) Development Test - Development testing of the fan shroud e.ssembly was conducted by NSFC. (b) Qualificat:'.on Test - HHC Report No. 3310 _. The qualifi~ation testing of the fan shroud assembly was conducted by MSFC. A portion of the testing was done by MMC. The latter included vibration and shock testing of the fan a$sembly, 20M42270~3, with the MDA hard mountad mufflers. Ule fan assembly success~ fully p'Isced th"se tests. The results of the 20M42270~3 fan shroud assembly tests are presented in MMC Qualification Test Report No. 3310. The dash three (3) 20M42270 assembly was used in the MDA. D. Mission Results - Ule crews' evaluation on the performance of the ventilation system was that the air circulation was more than adequate, the sc~eens on the inlet mufflers were an ideal size for collecting dust and debris and that the operation of the fan~muffler assemblies produced a low level acoustic noise output. It was very quiet. No problems existed with any of the system components. During SL~2 the fans were operated at temperatures below the design requirements. Ulis off~design operation did not adversely affect later fan performance. During the post SL~3 storage period cabin fan 2 remained on as a cooling fan for the rate gyro s i%-pa cIt. Ulis unscheduled operation added 1250 hours to the operating time accumulated by fan #2. As a result of the.extended SL~4 mission to 84 days, the total operating time for each fan at the end of the SL~4 manned mission was as follows; CSM fan ~ 4100 hours, cabin fanHJ.~3550 hours, cab ill fan1t2~4800 hours. Design operating life of the fans was 3360 hours but all fans ,;oere performing perfectly at the end of SL-4.· E. conclusions and Recommendations ~ The MDA ventilation system provided good air circulation to the CSM ond within the MDA. No hot or cold locations were found within the MDA. The fans continued to provide circulation long after their design operat~ng life. l~e crews' debriefing 'comments indicated that the muffler screens,. mesh size .14 ine x .14 in., was a good size to collect debris. It is recommended similar sized screens be used for future systems. Also it is recommended that future fan systems be capable of ground command or that a portable utility outlet be tied to ground command so thut a fan or other electrical component could be plugged into the outlet for command during unmanned periods. 2.2.2.2 ATM C&D Panel/EREP Coolant System A. Design Requirements - The ATM C&D Panel/EREP Coolant System design requirements were specified in several documents because the system crossed several interfaces. Ule requirements 2-121 were as specified below but when the same requirement appears in more than one dO~".ment, it is not repeated. The requirements pe>: AM/MDA ICD 13M02521 were ss follows: c Operating pressure - 37.2 psis maximum. 6 Inlet fluid temperature ~ 49 0 F to 780 F. • Fluid - high purity water plus additives. e Flow rate - 220 pounds per hour, minimum. o Allowable pressure drop - 6.75 pai @ 220 lb/hr. • Leakage - 35 cu-in. (from time of fill to end of 240 day mission). Requirements per EREP/MDA ICD 13H07397A* were pressure drop (EREP system) - 2.0 psi @ 220 lb/hr and lealtage - 171 cu-in. from time of fill to end of 240 day mission. Requirements as specified in ATM/MDA drawing 40M37870>" were a pressure drop of 3.0 psi @ 220 lb/h1: and a leak requirement of no bubbles at 300 psi GN2. B. System Description - ATM C&D/EREP Coolant System consisted of the hard tubing, flexible lines, valves, and cold plates associated with conducting a flow of coolant to and from the ATM C&D panel, the EREP tape recorders, the EREP C&D panel, and the 8192 electronics. MDA EC8 components included in the system were 4 port manual selector valve, ATM C&D panel flexible lines, EREP tape recordeF selector valve, and EREP flexible lines. The MDA system interfaced with the AM system which contained the pumps, heat exchangers, and accumulator. Configuration of the coolant system and components is shown in Figures 2.2.2-2 and 2.2.2-3. . *These requirements were inclusive in the AM/MDA pressure drop and leakage allocations. 2-122 A Atli C&D lLEnIllJ CONSOLI COOLANT /t.INES (:) 4-PORT SILECtOIl VALva Iln'MS LOOP TAPE IICOJ.DEIl SELl!CtoR VALVE illEr COOLANT FLEI HOSES (12) S192 ELI!CTROIUCS Figure 2 . '-.2-2 MDA ATM-EREP Coolant Systems Figure 2 . 2 . 2-3 AIM C&D Console Coolant Installation 2-123 The coolant system provided the support for cooling the ATM C&D panel and EREP electronic pacltages within the ~IDA. Heat loads generated by instrumentation ,~ithin the ATM C&D panel and the EREP equipment were transported by means of the coolant loop to the AN coolant system from ,~hich the heat was rejected to space by means 0 f the AM/~IDA rad ia tor sys tern. Fluid flow through the ATH C&D panel was aut.omatic 'vhenever the coolant pumping system ,~as activated. On the other hand, flow to the EREP system was controlled by positioning the four port manual selector valve. Flow control through the EREP subsystem was accomplished through usage of balancing £101" orifices and the EREP tape recorder selector valve. C. Test (1) Coolant Valve, Manual, 4 Port, Selector-~1l'!C pIN PD4700l9l. (a) Development Tests - The 4 Port Selector Valve was an adaptation of the Apollo glycol bypass valve as manufactured by AiResearch. The MNC design modification consisted of removing the electrical actuator and replacing it with a manually operated actuator. The fluid control portion of the two valves, including the pressure relief mechanism were identical. Development tests were performed primarily on the manual actuating mechanism. Cycle life tests were conducted to demonstrate capability to withstand the required number of operating cycles plus margin (475 wet cycles and 25 dry cycles). The actuating mechanism, including the position .locks, perfoJ."Illed all cycles ,~ith out malfunction and only a slight marking was witnessed as indication of ,~ear. Vibration testing was also conducted to verify that both the actuating mechanism and fluid control portion of the valve would not degrade under vibration conditions. There was no structural degradation as a result of this test and the valve performed well during functional tests following vibration. There was no measurable internal leakage at operating pressures using volumetric displace- ment and nitrogen gas over a 15 minute period. 2.-124 Allowable leakage was 1.54 cc/day of water or an equivalent of 2 scc (GN2) in 15 minutes. Also, there was no degradation of the pressure relief machanism as a result of the vib~ation testing. Relief pressures remained the same, within the accuracy of the pressurp. gauge, as pressures recorded prior to starting of the test. (b) Qualification Test - AiResearch, Report No. 71-7933 - Qualification testing on the 4 Port Selector Valve was completed on 21 October 1971. The qualification tests consisted of Physical Inspection, Proof Pressure, Over Torque, Ultimate Torque, Vibration, Cycle Life, and Burst Pressure. A performance test was conducted prior to and after each environmental test. There were no problems encountered during qualification testing. At the completion of q~alification testing, one of the tT,;\J teat units had no detectable internal lealcage and the second unit had a leakage rate of 0.8 scc (GNZ) in 15 minutes. External leakages for the fl.rst and second units were 9.2 x 10-9 Bcc/sec (He) and 2,3 x 10-6 scc/sec (He), respectively. The_waximum allowable externa~ leak rate was 1 x 10 scc/ sec (He). (c) Acceptance Test - Each valve received an acceptance test to demonst~ate quality assurance with respect to fabrication and performance. To sati.sfy the quality assurance requirements the valves received a visual \ J and dimensional inspection, a proof pressure test, and illternal lealtage check, an· operating torque check, a pressure drop test, a pressure relief test and an external l correct assembly and required per- formance. To satisfy this demonstration each valve received a proof pressure test, a leakage test, and a physical inspection. All valves met these requirements. (5) EREP Coolant Loop System Design and Development History (a) Design Considerations - In order to maintain minimum pressure drop, the initial sizing of interconnecting tubing was selected as ~ inch (O.D.) and cold plate tubing \qas selected as 3/8 inch (O.D.). This initial concept "as designed for series flow through the entire EREP coolant system, and was based upon a single tape recorder in the loop at one time. Flexible hoses constructud of reinforced silicone rubber ~ere selected and qualified by similarity to M509 (oxygen) hoses. Thermal studies revealed that all of the coolant to the EREP interface at minimum fluid temper- atures could r.,t be utilized without danger of causi.ng condensation on the heads of the tape recorder. In addition, it "as deemed necessary to permanently install a spare tape recorder. These factors resulted in a redesign incorpora~ ting an approximate 1/3 coolant flow by-pass to the ATM C&D Panel loop and to the primary or spare tape recorder loop. A selector valve , . , was incorporated to direct coolant only to the operational tape recorder. Coolant loading and prelaunch readiness studies indicated that the upper portions of the cold plates and interconnecting tubing would be subjected to vacuum prior to orbital insertion. Since the flex hose silicone rubber was Itnown to be significantly permeable to gasses, this could result in cabin gas being ingested into the coolant, both as free gas and in coolant solution. A review conducted by JSC, NSFC, MDAC-E and NNC concluded that the gas ingestion should be precluded by changing to non-permeable hoses, rather than the pump-accumulator system maintaining positive pressures. The system design was then changed to utilize convoluted stainless steel flexible hoses similar to those utilized by MDAC-E (i.e. the same supplier). Flexible hoses were required to accommodate installation toler~nces between equipment mounting racks, and to withstand the launch environment vibrations and displacements through the equipment mounting points. Test points were "designed out" of the system since these would have added a significant number of mechanical joints, and the overall leakage verification was considered to be a difficult manufacturing, build and test task even with the minimum required joints. Flared fitting inserts (Voi Shans) were incor- porated as a corrective measure for leaking or remade joints only, whereas the NSFC influenced systems (AN and ATN coolant tubing) specified general application of inserts. JSC cited some unsatisfactory applications of flared fitting inserts in previous applications. All flared fittings were made with the NS "precision" series of 32 rms finish on sealing surfaces, vs the "standard" NS fittings of 100 rms finish. Lockwires were not utilized ~--------y I I on the fittings since the joints leakage would be considerod failed by the time lockwire could become effective. The flsred joint dynamic susceptability at the specified installation torque ,~as demonstrated by inclusion of the connecting flexible hoses to the EREP Tape Recorder in the qualification"random vibration tes t. The shoclt mounts of the tape recorders allowed for the greatest relative motions between any segments of the coolant system. Tubing and cold plates were insulated to minimize cold radiant surface conditions and touch temperatures and to preclude surface condensa tion. (b) Test - In order to verify flow distribution by "design" rather than by "calibration" of the flight installation, a breadboard tubing and cold plate simulation was constructed. Breadboard tests provided the data and verification of flOl~ control orifices (diameters), flow bUlance vs flow range, leakage test methods and comparisons, flex line geometry efifects. cold plates flow vs pressure drop charactel'istica and blocked leg pressure drop values. The pressure drop and values to be tested were of small enough magnitllde to ·be affected by conventional flOl~ instrulllentation. There- fore, each simulated cold plate was bench calibrated for flOl~ vs pressure drop so that these system segments cOllld serve as flow- meters l~ith only pressure taps added to the representative flight configuration. The Tape Recorder Selector Valve flow charac" teristics vs position were determined to assure that no major flow 1isturbances would occur in the operating transition. In addition. opcratillg torque, lealtage and cycle life testing mlre performed as design verification tests. Qualification of this valve l~as accomplished by similarity to Apollo and Gemini applicatione and a vibration test to demonstrate lealtage and position integrity. Corrosion tests were conducted subsequent to system and component design verification tests to satisfy customer and associate contractor concerns regarding coolant inhibitors and dissimilar metals. These tests shol~ed slight corrosion to occur. but l~ell within acceptable rates for the duration of all Sltylab missions. EREP equipment modules which were replaced during MDA flight article preparations required d:t'ying and verification to 10l~ del~ points ("650 F to -300F). Initial test techniques l~e:t'e invalid due to the del~ pointers requi:t'ing a continuous gas supply, and the test method allowing cold plate purging from a d:t'y N2 supply. The acceptable test technique for use with any type del~ pointer required a p:t'essure locltup (50 psig for 2 hours or more) then a slow bleedoff through the dew pointer to the maximum steady state value. (c) Conclusions - Flol~ balancing and sensitivity to geometric tolerances l~ere determined to be satisfactory for the thermal cooling criteria. JSC :t'ep:t'esentatives concurred by breadboard tests that test points or calibration controls l~ould not be required for this system. Lealtage techniques and comparisons resulted in the follol~ing conclusion: • Bubble testing is Useful in off module. sub"assembly testing to eliminate gross leaks. • Helium - mass spectrometer probe tests allol~s some bad joints to pass l~hen comM plete peripheral access is not available. • Water volumetric testing is useful for a baf'is of establishing test . comparisons, but :t'equires too long a test period to be practical for on module production testing. o Gas vo1umetrics tests provide the highest confidence of guaranteeing overall "ater leakage "Uhin practical test time limits. • The mass spectrometer evacuation test method, with external helium flooding pro- vides the best leak isolation technique for the levels of liquid lealtage required to be detected. Changes in design concept, such as the change from series flow to parallel flow. should be accompanied by the appropriate size reduction accordingly. A reduction in size to 3/8 or 5/16 inch tubing would have simplified the installation and increased mechanical flexibility with no probable time cost overall. Metals used for construction of new coolant systems should belong to the same family group of dissimilar metals. The present system contains aluminum/stainless steel junctions. Even though the MDA/EREP coolant system has performed satisfactorily, every system anomaly has resulted in re-reviews and tests for corrosion. (6) System on Module - Flow and pressure drop and leakage tests were the only complete coolant loop system teste performed "on module". No specific thermal coolant flol~ tests were performed, since off module tests of 'experiment assemblies showed that thermal performance was satisfactory when the coolant flO~l and inlet temperature was I~ithin specified limits. Flow ba1~ce and distribution was demonstrated by powered operation of EREP modules with tubing surface temperature measurements during systems tests at St. Louis. Lealtage tests "on module" were performed to a "Volumetrics" measurement limit of 1.0 x 10-3 sccl sec of N2~ The volumetrics test method verified all joints in the coolant system, from the AM inter- face, which included 144 joints. The "Volumetrics" "'. instrument shol~ed a high sensitivity to temperature, such that the entire system had to be Irrapped I~i th a super insula tion blanke t, all ligh ts turned off inside the ~IDA. and all personnel restricted from the test 'area during conduct oJ: system lealtage measu):emant. In order to achieve an aceeptable "Volumetrics" measurement, a helium mass spectrometer probe (sniffer) test to a maximum reading of 2.5 x 10MB scc/ sac I~as imposed as the sys tern build I~as in process. During the System Test and Clledtout Requirements (STACR) checltout, this probe te:>t '~as relaxed to 5 x 10~7 scc/sec helium I~hich still al1ol~ed sufficient volumetrics test margin. D. Mission Results M During SLN2 no anomalies I~ere observed. At the end of the SLN3 mission anomalies occurred on pump "A" as witnessed by noise and flol~ drop. The follol~ing is the ATM C&D/ERE~ coolant loop history on SL-4 through splashdolm: The ATM C&D coolant loop I~as activated for SLN4 on DOY 321 at 21:10:00. Shortly after activation erratic flow fluctuations, from pump "B", I~ere observed I~ith the flol~ dropping from 30 to 50 pounds per hour. The dropouts in flol~ I~ere a random occurrence happening once an orbit then not occurring for several orbits. The flol~ dropouts became larger, up to 100 pounds per hour as mission operation time continued. On DOY 336 pump "B" I~as turned off and pump "c" was turned on, almost immediately erratic flol~ conditions \~ere observed on pump "C", I~ith dropouts up to 100 pounds per hour. As a result of the above mentioned erratic flow conditions tha following investigations I~ere conducted. All hard\~are in the system I~as reviel~ed for failure modes similar to what \~as e:mibited on orbit. The 4Nport selector valve I~as the first suspect. Tests \~ere conducted in St. Louis on the Back Up Article and on· orbit by the crel~. The tests con- sisted of rotating the valve handle at 100 increments from a byN pass position to a flol~Nthrough pOSition and baelt again. Test results sho\~ed that flO\~ varied as the valve handle I~as moved from one position to the other, but the erratic flow fluctuations could not be duplicated. 'Ille 4~port selector valve I~as :ruled out as the possible cause. System contamination \,as suspected as a possible cause. The pump flows on orbit had never been as high as on the !\r,'und. F10l; rates were from 285 to 300 pounds per hour on the ground dropping to 240 to 250 pounds per hour on-orbit. The 240 to 250 p,'ullds per hour flows were very close to the relief valve setting around the pump, it was felt that perhaps some of this flOl, \,as relieving back to the inlet side of the pump; If contamination \;ere the cause, the filter should show some evidence of it. Inspection of the filter by the crew on DOY 352 revealed some contamination on the filter as \,ell as bubbles and foam at the quick disconnects. The following is a description of the filter inspection by the ere\;. "Some debris looks lUte little pieces of human st,in. Took one of the large pieces and put on end of my finger and let dry, rubbed \;ith thumb and it immediately disappeared in a sort of a dry pOl,der and sort of smeared over my finger. Nhat it really looks 11l,e is little bitB of lubricant that have gathered together and became sort of a little plate. There a~e 5 pieces ~ mm, 6 pieces" 1 mm and 4 pieces .. 2 mm. Considering the sur.faee area of the filter and number of pieces found \,e feel this is a negligible amount of contamination." Analysis of filters returned from SL-2 and SL-3 did not reveal contamination that could cause flo~' fluctuations. A revie\, of all available system flight data from SL-2 and SL-3 was conducted. It was found that 8 dropouts had occurred on SL-2. 23 dropouts on SL-3 and to date 21 dropouts on SL-4 and dropouts were becoming more frequent. (Sec Table 2.2.2-1 and Figure 2.2.2-4 for flow dropouts data and sample plot of a dropout. ) Another pos3ible cause of flow dropouts could be that the coolant system could have gas in it. Gas could have been ingested into the system, nither during ground testing or on-orbit operations. The filter had belm replaced 4 times on-orbit and the accumulator has Il viton bllldder. Leakage through the bladder Ilnd Quick Disconnects \rould be the most likely suspects for gettine; gas into the system. On DOY 352 the liquid/glls sepllrator procedure W(lS given to the C1:O\'. The Space Suit Umbilical System (SUS) loop separator \;(\s installed into the ATH C&D Coolant loop replacing the filter. After several hours of operation s'~itching from pump "B" to "C", the flow increased to 295 pounds per hour on pt1mp "B" and 280 pounds per hour on pump "e".. Previously both pumps had been flowing 2/~0 to 250 pounds per hour. t~hen the gas removal procedure was completed, a new filter l,as installed into the oystem and pump "C" was activated. Flow was normal at 280 pounds per hour. Pump "B" was then activated and the flow was 297 pounds 2~136 MISSION DOY TIME GMT FLOH RATE CI!ANGE DURATION OF DROPOUT (LB M/HR) (MINUTES) SLM2 153 5:27 239.5 to 91.2 1/2 to 1 157 2:10 240.6 to 198.6 1 to 2 157 3:22 240.6 to 183.5 1 to 2 159 18:27 240.6 to 19l.8 4-1/2 to 5M1/2 161 2:16 240.6 to 157.8 1/2 to 1 164 0:44 233.6 to 36.3 1/2 to 1 164 7:40 241.8 to 42.2 1/2 to 1 171 20:36 245.3 to 216.1 2 to 3 SL-3 214 6:09 235.9 to 88.9 3 to 5 218 13:47 231.3 to 161.3 5 221 12:26 230.2 to 10.6 1/2 to 1 223 1:10 231.3 to 81.9 1-1/2 to 2 226 5:18 227.8 to 5.9 1-1/2.to 2 227 21:03 227.8 to 153.1 1/2 to 1 229 1:45 230.2 to 42.2 1/2 to 1 230 1:01 229.0 to 11.8 1/2 to 1 232 15:50 230.2 to 81.9 1/2 to 1 236 18:14 228.9 to 154.2 1 to 1-1/2 237 15:25 231.3 to 4.8 1 to 1-1/2 242 16:54 234.8 to 85.4 1/2 to 1 247 19:51 M 234.8 to 32.8 3 to 4 19:55 248 15:49 235.9 to 37.5 4 to 5 248 19:19 237.2 to 28.2 252 4:20:30 234.8 to 5.99 1/2 to 1 252 3:01:30 234.8 to 11.83 8-1/2 253 18:40:30 234.8 to 21.2 1/2 to 1 253 13:08:00 233.6 to 24.7 Data Time Dropout 256 4:28:00 240.7 to 91.2 1/2 to 1 259 0:49:30 238.3 to 11.83 1/2 to 1 259 15:13:00 238.2 to 161.27 1/2 to 1 262 1:37:00 238.3 to 25.8 1/2 to 1 SL-4 321 23:1lf 252 to 212 1/2 to 1 321 23:19 240 to 191 1/2 to 1 323 23:06 249 to 99 1 to 1··1/2 323 23:10 250 to 25 1 to 1-1/2 334 15:09 250 to 110 1/2 to 1 334 15:10 220 to 110 1/2 to 1 335 01:00 240 to 190 1 Table 2.2.2-1 Coolant Loop Dropout History 2-137 MISSION ~ TIME GMT FLOW RATE CHANGE DuRATION OF DROPOUT 335 01:02:30 336 10:07 338 12:25 339 05:33 340 10:57 340 09:00 340 07:38 343 12:37 344 7:04 3l}5 00:38 345 03:42 345 10:36 346 03:14 346 10:17 (LB H/HR) (MINUTES) 220 to 145 235 to 0 230 to 160 Fluctuations 220 to 150 240 to 120 2l}0 to 140 240 to 120 240 to 10 240 to 0 240 to 157 240 to 12 240 to 100 From 243 to 232 And Cycles 227 to 259 244 to 217 5 1-1/4 1 2 1-1/4 3 (min imum) 2 maximum 2 maximum 2 maximum 1/2 approximately 1/2 Table 2.2.2-1 (Concl~ded) !!' ~ p., ~ iii ...... ~ ~ ~ is "" H • r.. I-' Ei to ~ '" a a '-' p., Ii! .E::. ~ '-' :s Ei ; developed for McDonnell Douglas, Eastern Division for use in the Airlock Module • ~wrtin Marietta procured the same part for use on the MDA hatches. Development testR conducted were vibration, shock and flow tests with performance evaluation before and after cach test. The vibration test consisted of a high level random test of 10 Grms; the shock test consisted of synthesized shoclt pulses of 1500g msximum per IN-ASTN-AD-70-1. The test unit sustained no physical damage and passed all performance tests after the environ- mental exposures. (b) Qualification Test - Accessory Products Company, Report No. 500200-1 QTR - The equalization valve was qualified to requirements set forth in McDonnell Douglas procurement specification 61B8300l4. These requirements were as stringent as those of the MDA, therefore upon qualification to these criteria, the valve IgaS qualified for use in the MDA. Qualification testing of the valve was completed on 2 April 1971. The tests consisted of the following environmental tests: High and Low Temperature, Oxygen Atmosphere, Vacuum Exposure, Vibration'- High Level Random, Shock, Cycle Test. Limit Load Test, Proof Pressure. Ultimate Load Test, Burst Pressure, Salt, Fog and Humidity. A performance test was conducted after each environmental test. No problems were encountered during the qualification tests and the test units successfully passed all environmental and functional tests. (c) Acceptance Test - Each valve received an acceptance test to demonstrate suitable quality, correct assembly and required perfor- mance. To satisfy thin demonstration the valves were visually and dimensionally inspected, checlted for flow rate capacity, subjected to proof pressure, tested for internal and external leakage, and the detent spool was examined for centering adjustment. All valves thus tested met the acceptable requirements without difficulty. These valves 1gere installed in J o <, ( ., the MDA docking port hatches at a position approximately 4 inches from the hatch seal ap. The length of the chain attaching the cap to the valve body could, if the cap was unscrewed from the valve, a110\1 the chain and/or cap to become lodged between the seal and the hatch lip upon closing the hatch. Martin Marietta procured the valve. PIN 61BB30014-S. from Accessory Products Company and changed the length and location of the chain prior to installing the valve in the hatch. D. MJ.ssion Results - The axial hatch pressure equalization valve was 0:" ~rated by each of the three crews and the .6. P gage monitored during hatch opening activities. The equalization valve and cap was used for an unprogrammed toxic gas sampling during SL-2 activation. A spare cap was modified to accept a gas sampling apparatus. This cap and the gas sampler were stowed in the SL-2 command module. Prior to SWS/CSM pressure equalization the crew removed the flight cap from the valve and attached the modified cap and sampler. The valve was then opened and a sample of the atmosphere in the MDA was taken. When the gas was found satis- factory, SWS/CSM pressure equalization was performed, and the hatch was opened in a normal nmnner. The system performed properly during all operations. E. Conclusions and Recommendations - Since the equalization system operated satisfactorily during all missions, it is concluded that the system was designed adequately. However, from the experience gained d'triug this program. it is recommended that a differential pressure gage need not be required when one of the volumes to be equalized is small (greater than 5:1 ratio) or if both volumes are small. The equalizing process could be accomplished procedure1y by simply waiting a short length of time after opening the equaliza- tion valve before opening the hatch. However, if a visual gage is to be required, the accuracy requirement should be at least 0.1 psi. This would allow a gage to be designed with a greater pressure range and therefore a stiffer bou:r:don tube which would be less susceptible to gravity effects and shoclt testing practices. In addition it is recommended that future equalization valve designs incorporate a detachahle cap similar to this Sky1ab valve in order that instruments suc~ as gas samplers can readily be attached to them for unscheduled operations or usage. ..-.----~--, .. ! I l This Page Intentionally Left Blank o 2-162 f,., ! ~-~-- .. 1 , 2.2.3 Thermal Control System (TCS) 2.2.3.1 Passive System A. Design Requirem~nts and Analyses - Design requir.ements for the passive MDA are contained in the MDA CEI Specification, the AM and CSM ICDs and several equipment Some design requirements were applicable only to the Passive TCS. Others were applicable to the Active TCS. Many requirements, however, were applicable to both the ~ctive and Passive TCS. Table 2.2.3-1 indicates CEI requirements for the MDA. An identifying letter, either (~~A), or (15) preceding each requirement, indicates whether the requirement was pertinent to the Passive TCS. Active TCS or both systems respectively. Tables 2.2.3~2 and 2.2.3-3 indicate vehicle ICDs and equip- ment requirements. The (P),(4), or(15)identification convention, indicated above, is applicable to these tables. The primary requirements as imposed by the above mentioned CEI and ICDs were that average wall temperature be controlled between 600 F and gooF during the manned mission period and between 400 F and gooF during the orbital storage mode of operation. No requirement was imposed on the MDA to meet comfort criteria during the manned mission phsRe. However, it was an objective to provide environments that fell within the comfort box presented in Figure 2.2.3-1. Numerous analyses were performed in support of the effort directed toward the meeting of design requirements. Table 2.2.3-4 summarizes these analyses. A discussion of these analyses follows: (1) . Systems Studies - Passive TCS - Several systems studies were performed on the Passive TCS. A description of these studies is indicated below: (a) Error and Sensitivity Anal.ysis - The purpose of this analysis was to predict the tolerances that could exist on calculated MDA tpmperature and heat balance due to errors and uncer~ainties in basic enVironmental and material property assumptions. Calculated MDA external temperature values were subjected to preliminary error(continued on page 2-163 (A) Distribute atmosphere from the AM ECS (Para 3.1.1.2.4.1.1a) (A) Cabin fans and diffusers will provide capability to maintain atmosphere at crew stations between 15-100 feet/min (Para 3.1.1.2.4.1b) (A) Atmosphere shall be delivered from the MDA to the CSM by a fan/duct system (Para 3.1.1.2.4.1.1c) (A) Wall heaters to be thermostatically controlled to approximately 4SoF during storage and 700 F during manned operation. Penetration heaters to be thermostatically controlled (Para 3.1.1.2.4.1.1e) (A) Heater elements shall be protected by overtemperature thermo- stats to deactivate individual heater circuits (Para 3.1.1.2.4 .l.le) (A) An equipment coolant system shall be incorporated to distribute coolant fluid from the AM thru the MDA to the ATM C&D console and EREP System (Para 3.1.1.2.4.1.1f) (P) MQA passive thermal control shall consist of high performance insulation, thermal paint and material selection to meet the thermal requirements herein (Para 3.1 • .1.2.4.1.2) (P) The high performance insulation shall be attached to the primary str.ucture with Velcro and shall be laced together with dacron lacing and boot hooks. The multilayers shall be assembled by means of nylon sl,iftachment devices (Para 3.1.1.2.4.1.2) (~) MDA shall be designed to be purged internally (Para 3.1.1.2.4.1.2a) (P) MDA shall incorporate provisions for purging the insulation blanket with GN2 (Para 3.1.1.2.4.1.2b) (p) Insulation shall be installed on the external windol' cover to minimize heat loss (Para 3.1.1.2.10.2.2) (A) The S190 window shall incorporste heaters to prevent moisture condensation on the glass during all periods when the window is in use (Para 3.1.1.2.10.2.4) Table 2.2.3-1 MDA CEI Requirements Summary - TCS , , (B) Docking port-hatch handle temperatures shall be maintained betwaen +1050 F and +350 F during docking and all manned operations (Para 3.1.1.2.10.3.1) (B) The MDA shall be designed to withstand effects of space environments as in TMX-53798 and earth environments as per TMX-53872. Thermal properties of the sun and earth (albedo) shall be as defined in TMX-53957 (Para 3.1.2.4) (B) The MDA shall be designed to withstand thermal stresses and shock resulting from atmospheric ~onditions defined in TMX- 53872 and NASA TMX-53798 (Para 3.1.2.4.2) (B) Net total steady state heat load to the MDA atmosphere shall be defined in ICD 13M02521" (Para 3.1.2.8.7) (B) MDA to provide equipment environments as "follows: ~ehicle External Environment Internal Environment Condition T max (OF) Trnin (OF) Tmax (OF) Tmin (OF' ~round lHold & 90 40 90 40 ~scent Orbital Coastl 277 -180 90 40 Storage !Active IEcs Mode 277 -180 90 50 (Para 3.1.2.8.7.1) (B) Local wall temperature not to exceed 1050 F (Para 3.1.2.8.7.2) (B) MDA wall average area temperature shall be a minimum of 600 F at launch and during the active ECS mode, and a minimum of 400 F during the orbital storage modes (Para 3.1.2.8.7.2) (B) Maximum wall averaga area temperature shall be 900 F during the active ECS mode (Para 3.1.2.8.7.2) (B) The external temperature requirement for the axial docking port interior walls shall be -40oF min to +200oF max (Para 3.1.2.8.7.2) Table 2.2.3-1 (Continued) '0 (B) The interior wall of-the axial docking port between the drogue assembly and the pressure hatch will stabilize to an average temperature between 400 F and 900 F within 6 hours after successful CSM docking (Para 3.1.2.8.7.2) (P) The external paint shall be of a type which will aid the thermal characteristics of the passive environmental control system (Para 3.3.10.1) (P) H Requirement applicable to the passive TCS (A) - Requirement applicable to the active TCS (B) ~ Requirement applicable to both the passive and active TCS Table 2.2.3-1 (Concluded) AM/'MDA ICD (P) • MDA Insulation Purge " ~low rate 5 lb/min when supplied with 150 psig gas at 70oF. (B) • Bulk Atmosphere Temperature within the MDA of 600 F to 90oF. (B) • Internal Mean Radiant Environment " Manned Orb:l.t Ascent & ::rbit Storage Minimum 600 F Maximum 900 F (A) • AM/MDA Water Loop Requirements o Pressure Drop 6.75 psid @ 220 lb/hr • MDA Maximum Heat Additions 1335 BTU/hr at 7SoF. Influence of water supply and compartment temperature shall be as determined from "AM/MDA Environmental Data". MDA/CSM ICD (B) • Temperature Requirements just before docking. MDA Docking Ring MDA Drogue Maximum of Minimum of 200 200 50 "100 (B) • Temperature Requirements after docking. CODE ~ " Requirement applicable (A) - Requirement applicable (B) - Requirement ~pplicable to the passive TCS to the active TCS to both the passive and active TCS. Table 2.2.3-2 'MDA Reqllirements Summary, AM/MDA and MDA/CSM IeDs f ~ ~ MDA/CSM ICD ITEM MnA Docking Rinl! MDA Drogue Prior to Tunnel Pre s sur izs t ion Tmin "F Tmsx of 2.0 200 -100 200 (B) • MDA Atmosphere Supply to CM After 8 Hours T, of 65 ± 25 N/A Flow 100-200 (ACFM) Temgera ture (1) 67 F to 80°F Quasi Steady State Tmin U]; TmsxuF 50 50 AM Controlled Dewpo,int (2) 46°F to 55°F 90 90 (1) Attainable by exercising operational constraints. CODE (2) During specified brief mission periods dewpoint may exceed the above limits. (P) - Requirement applicable to the passive TCS (A) - Requirement applicable to the active TCS (B) - Requi~ement applicable to both the passive and active TCS Table 2.2.3-2 (Concluded) AVllMllE lIDIGS LOCAL DEW lillLATIVil T.'crEllIU.I. INIERllAL TEMP WALL POINT IIDH!DI~ TlllP. DOCIDlENT PERIOD TEMP of of 'F of 7- 'F FIL..'i VJJ]LT PI'..EI.Alt"CR NR 40 to dO 40 to 80 NR 0-45 lnt leO ORB. COAST NR 40 to 80 40 to 80 h"lt 0-45 NIt Ol'ERATIONA!. NR 60 to 80 60 to 80 NR 30-ao liR SI90 PRPLAUN:JI -40 to 160 -40 to 160 -40 to 160 NR 0-100 -40 to 160 ICD ORB. COAST 40 to 90 40 to 90 40 to 90 h"R 0-45 -180 to 277 OFT:;RATIONAL 60 to !lO 60 to 90 so to 105 40 to 60 30-95 -180 to 277 8191 pRELAUliCII -40 to 160 -40 to 160 -40 to 160 NR 0-100 -40 to, 160 lCD OlUl. COAST 40 to 90 40 to 90 40 to 90 NR 0-45 -180 to 277 NO OPlffiXUONAL 60 to 90 60 to 90 SO to 105 40 to 60 30-95 -180 to 217 , PRELAuNcF 0-55 ,... S192 40 t~ 120 40 to 120 40 to 120 NR -40 to 160 en !CD ORS. COAST 40 to 90 40 to 90 40 to 90 NR 0-65 -180 to 277 • .0 OPERATIONAL 60 to 90 50 to 105- SO to lU5 40 to 60 30-95 .. 180 to 277 M512 l'RELA1JllCll -40 to 160 -40 to 160 .. 40 to 160 NR 0-100 NR lCD ORS. COAST 40 to 90 40 to 90 40 to 90 h"R 0-45 NR Ol'EMIIONAL 60 to 90 60 to 90 SO to 105 40 to 60 30-95 b"R Sll09 PREIJlU!,'()1I "/.0 to 160 -40 ttl 160 -40 to 160 NR 0-100 NR ICD ORB. COAST 40 to 90 40 to 90 40 to 90 b1l 0-45 NR OPEMIIONAL 60 to 90 60 to 90 50 to 105 40 to 60 30-95 NR RNllH Pru;LA1ThllH -40 to 1ijO -40 to 160 -40 to 160 NR 0-100 NR ICD Oitn COAST 40 to 90 40 to 90 40 tc 90 b"R 0-45 NR OPERATIONAL 60 to 90 60 to 90 50 to 105 40 to 60 30-95 NR ESE l'RELAUNCH .. 40 to 160 -40 to 160 -40 to 160 NR 0-100 NR leO ORB. COAST 40 to 90 40 to 90 4G 1:0 90 NR 0-45 NR OPEMIIONAL 60 to 90 60 to '0 SO to 105 40 to 60 30-95 NR L-B!iND PRELAiJN::H NR NR NR Int IlR 20 to 100 !CD ORB. COI.ST 1m 1m Int NR NR -100 to 217 OPEMIIONAL 11K NR NR NR NR "13v to 20 PROlaN PRET.AUNCH NR ~!R ~IK NR N!\ NR SPECT ORB. COAST NR NR NR l1R NR -ISO to 277 ICD OPEMlIONAL 1m NR NR NR NR (1) Aln:o:mOLLRD l'AR.!METER Table 2.2.3-3 MilA Requirement Summary - Experiments 95 90 85 6' I. l"I 80 ~ t-t 75· '-' ::r ~ ~ "" 70 1:J ~ , . < 'I ! 65 ~ 60 I:l en 5 ~ 50 1 45 ~ 50 55 60 65 70 75 80 85 90 MEAN MDA WALL TEMPERATURE: _ of Figure 2.2.3-1 MDA Comfort Box 2-170 A. Systems Studies M ~assive TCS 1. Error and Sensitivity Analysis, 2. Wall Penetration Heat Leak Analysis 3. ~IDA Xnstalled Equipment M Passive Thermal ~eatures 4. ~A Heat Bdlacice and Temperature Distribution 5. Development Test Data Correlation Analysis B. Insulation Blanket 1. Design Support Analysis 2. ~erformance Evaluation 3. Manufacturing Analysis 4. Ascent Venting Study C. F;I,berglass Standoffs 1. Conductivity Assessment 2. Heat Leak i\nalysis D. Low Emissivity Tapes 1. Fiberglass standoff ,coatings 2, L-band Antenna ':cruss Worl, 3. SM191. 192 closure Angles E. Surface Coatings 1. ~arametric Studies 2. Docking Port Component Studies 3. Striping Effects Analysis F. Insulation Purge Syst.em Table 2.2.3-4 Passive ~A TCS Analyses t analysis early in the program to predict the effects of possible variations in boundary parameters such as surface emissive properties, solar constant, earth albedo, earth IR and ~IDA/ 8T8 raeiatr,r temperature. This preliminary analysis l~as followed up in the second half of 1970, with an uncertainty analysis l~hich had the purpose of evaluating and updating the impact of the above mentioned parameters with the addition of configuration variables which became apparent as the detailed design evolved. The result of this analysis work was finally incorporated into later studies which evaluated ~A module heat leak, temperature distribution, heat-up and cool-down rates. (b) Wall Penetration Heak Lealt Analysis - The purpose of this analysis was to evaluate miscellaneous heat leaks through the ~A wall due to electrical and mechanical penetrations of the insulation blankets. Approximately 17 heat leak sources were identified and analyzed. The most significant of these heat leak sources included fiber~lass rings and rails, insulation blan!l.et, 8191/8192. experiments, radial docking port, ATM feed thru cables, electrical penetration plate and the L-band truss. Individual detailed computer models were built for many of these heat leak sources. (c) ~A Installed Equipment - Passive Thermal Features - These analyses were carried out to predict the effect of the MDA imposed environments on MDA equipment surface temperatures. The prime objective was to select passive features that would assist in keeping equipment surface temperatures low. This l~as desirable in order to prevent temperatures ·from exceeding leD limits and from exceeding crew touch limits. Performance of the analyses involved con- struction of computer models including equipment details and selected MDA boundary conditions. Emphasis was placed on passive features such as equipment surface properties to increase radiation heat transfer, and mounting details to increase the conductance hoat path through the particular piece of equipment. The EREP Support Equipment, MSl2. experiment, Back Up I/LCA,and Video Tape Recorder are (d) (e) typical of equipment receiving this detailed analysis. As final designs evolved, computer models were upda ted to reflec t upda ted hea t generation profiles and analyses ware updated. MIlA Heat Balance and Temperature Distribution Studles - 1'hese 'studies were carried out to determine the characteristics of the MIlA l'assive Thermal Control System in maintaining acceptable t'lmperature levels, both internal and external. Subsequent analysis created the thermal netlqork model for the internal MDA es.tablishing a basis for the internal heat balance. The output of this effort was used to select external coatings, establish interface requirements Iqith CSM and STS and also provide information on to what extent the basic l'assive TCS may need to be supplemented with Active means such as wall heaters and atmospheric systems. This information was also used as input into the AM/MDA environmental control data book. Correlation Analysis of Development Test Data - The great majority of l'assive TCS testing was accomplished on the MIlA Thermal Component Test conducted at MSl.'C starting in September 1968 Iqith a final series of tests completed in August 1970. This testing was supported by analysis to define the facility requirements, test conditions; and to provide thermal math models for test data correlations. These models were used initially to determine overall ~IDA wall performance in both steady state and a tempera- ture decay morie. New, more detailed, models Iqere developed to analyze individual heat paths to assign the contribution of the insulation blankets, the fiberglass standoffs and insulation g&ps. A new set of test runs and test correlation analYSis were made necessary when it Iqas found, upon test article disassembly inspectio~ that the original fasteners had failed, Significantly changing the heat paths in the structure. The final series of test runs in August 1970 used a test article which included the do cIting port and certain fabrication variations discovered in the disassembly inspection. The analytical models were revised to reflect these features. 2-173 • - 'T (2) Insulation Blanket (a) Design Support Analysl!s - These analyses were aimed at establishing the design of the insulation blanket. Incl<1ded Wbfe heat flow calculations aimed at establishing design features such as the number of layers of aluminized mylar, emissivity of outer layer" effect of nylon swiftachments, emissivity requirements for fiberglass blanket border, effect of mounting blankets off of the meteoroid shield in certain MDA areas, etc. These studies were done prior to the final blanket design to evaluate potential design features and were terminated when the design was fit/alized. Most of these special evaluations involved separate computer studies of each item being investigated. (b) Performance Evaluation of Installed Flight B1l::nlcet - The purpose of this task was to arrive at an accurate estimate of the heat flow expected to occur through the blanket during flight. Computer case studies were conducted to predict effects of lateral conduction through the blankets parallel to the alUminized mylar layers caused by butt joint thermal shorting at tab areas, and effects of blanket mounting on the vehicle. Test results from the thermal development test were compared with results of these studies in order to arrive at predicted blanket performance for the MDA flight vehicle. (c) Manufacturing Analysis, Insulation Blanket - Numerous calculations \~ere made to establish effects of special problems associated with installing the blankets of the MDA pressure shell. These analyses resulted in recommending fi~es to local problems as they occurred during the manufacturing phase. (d) Ascent Ventiug S' 'v. Insulation Blanket - Available tes t informa tiot! ;'n\ other programs were reviewed and analytical cillculations were performed to assure that the insulation blanket would vent properly during ascent. (3) Fiberglass Standoffs 2-174 • (a) Fiberglass structural standoffs ,;ere analyzed for the purpose of determining material thermal con- ductivity and also conductance of the attach points. A detailed math model ';as r.onstructed of a 12 inch section o. fiberglass laminate ,;ith heat flow values calculated using temperature difference and heat inputs from tests. (b) Additional analysis was carried out on fiberglass rings and rails to assess heat losses and provide means for retarding same (Sec Paragraph (1) (b) Wall Penetration Heat Leak Analysis). (4) Low Emissivity Tapes - Analysis was carried out to identify areas of potential overboard heat leak and to assess the possible benefit of application of 1m; emissivity tapes. It ,;as revealed that an aluminum coated mylar tape ( € Q 0.1) applied to selected surfaces to reduce radiative heat paths could significantly rp4uce hea t 1ealt. Detailed analysis was performed on the L.l.berglass standoffs, L-Band antenna truss, an~ S191 and S192 closure angles to determine the most advantageous use of tape • . (5) Surface Coatings Analyses - Surface coatings were the subject of three basic analYGis efforts. The first, and most extensive, was undertaken as part of thermal para- metric studies ,;ith the purpose of selecting an llptimum coating for use on external meteoroid shield surfaces under various operating modes. This study evaluated maximum and minimum heating rates, external and internal tempera- tures at various orientations and beta angles with a/€ as the independent variable. Computer runs were made for both manned and storage modes and a selection of b1aclt paint ,;ith a = .95 and € Q .86 was made. A second study was made which evaluated the effect of docIting port component surface properties upon heat loss and component temperature levels. The heat loss was found to be a weak function of internal emissivity and temperatures did not exceed allowable levels. The third study was in the nature of an update of earlier studies to assess the effects Clf a white stripe painted about the circumference of the MDA cone. (6) Insulation Purge System Analyses - Analysis \;as carded out on the insulation purge system in several areas; preliminary studies conducted at HSFC established the 2-175 initial requirement early in 1969. Purge system studies to establish system pressures, line and orifice sizes and flo\~s were completed in the first half of 1970, and were later revised t.;, include provisions fOl' S190 windo\~ purge. Subsequent analyses \~ere carried out to determine the effects of purge gas on ~IDA temperatures for various operational and ambient conditions on th~ launch pad. B. Functional Description - The Passive Thermal Control system controlled the overboard heat loss from the ~A interior to a value that allowed the Active TCS to control internal temperature. The ~A Passive TCS consisted of the following principal parts and features: insulation blanket assemblies, use of fiberglass as structural standoffs and spacers, use of aluminized tape and thel-mal control paints and coatings. While not used in flight, the insula tim, purge system was generally discussed in conjunction with the Passive TCS. A schematic of the passive Thermal Control System is shown in Figure 2.2.3-2. Paints/Fi nishes Fiberglass Docking Port Ring (Typl "Aluminized Tape • I nsulation Purge Line lTypl Insulated Window Cov&r • • Fiberglass Rings and Rails (TYPl Insulation Blanket Figure 2.2.3-2 Passive Tl1ermal Control System Schematic (1) Insulation Blanket - The insulation blanket consisted of 91 la)ers of perforated double aluminized mylar separated by dacron netting. The blankets were held in position on the MDA exterior by using lacing and "boot hooks". The mul ti-layers were held together by the use of nylon swiftachments. The insulation blanket was placed between the MDA pressure shell and the radiator/~eteoroid shield . The design of the insulation blanket allowed the multi-layer aluminized mylar to act as radiation shields . This retarded the flow of heat from the MDA. A typical insulation blanket installation is shown in Figure 2.2.3-3. Further discussion on the insulation blanket is included in this report under the structures subsystem, Paragraph 2. 2.1. Figure 2.2.3- 3 Insulation Blanket with Fiberglass Rings and Rails 2- 177 I -......- (2) Fiberglass Standoffs - The use of fiberglass as structural standoffs and spacers retarde1 heat transfer from the MDA interior overboard due to the low thermal conductivity of the fiberglass. These standoffs took the form of circumferential rings and longitudinal rails to thermally isolate the MDA pr~ssure wall from the external meteoroid shield . Fiberglass sta"doffs are shown in Figure 2.2.3-3 . (3) Low Emissivity Tapes/Paints & Coatings - The use of low emissivity aluminized tape and paints and coatings having special thermal properties also retarded heat transfer overboard . Low emissivity tap~ g were used principally on the L- band truss and the fiberglass standoffs to reduce heat l~ak in potentially high loss areas. Tape was al&o used in several other local areas such as the S192 and S191 penetrations. Use of tape is illustrated in Figure 2.2 . 3-4 . Use of thermal paints is illustrated in Figure 2.2 . 3-5, EMISSIVITY TAPE Figure 2.2.3-4 Low Emissivity Tape On L-bsnd Truss 2-178 ) Figur 2.2 . 3-5 Thermal Painte on MDA Cone (4) Insulation Purge System - The insulation purge syqtem was used only prior to flight . The system pr ovided dr y GN2 distribution for con~itioning the insulation bl anke t and S190 window at various times during MDA ground operations , storage , and transportation. The exterior of the MDA pressure sh 11 was encircl ed with a network of p rforated ·tubing. This tubing network, located beneath MDA insulation blankets , was the gas distribution system. It was used for purging the MDA insulation blankets and the exterior sur face of the S190 ~indow with dry gas ous nitrogen prior t o launch and at other times when the MDA was no t in a conditioned environment. 2-179 A photo£raph showing a section of the system is shown in Figure 2.2.3-6. After launch, the insulation purge system served no purpose. F , " lre 2 . 2 . 3-6 Insulation Purge System, Typical Installation 2- 180 C. Test - The Bassive !herma1 Control System including insulation blan:tets, fiberglass stand-offs and external thermal coatings was evaluated thermally as part of an MSFC-ASTN MDA Thermal Component Hall Test Program. The test {lrticle incorpo:fated two 880 arc ~IDA barrel sections, seven feet long, forming an elliptical cylinder. The test article wan sections consisted of the aluminum pressure l~a11 with insulation blanltet, fiberglass structural standoffs and meteoroid shield inntalled. The test article also had the capability of having two flight-simulated radial docking ports installed so that wall/port thermal effects could be tested. Significant tests were conducted during November and December 1969 in a vacuum chamber at MSFC. The purpose of this testing was to determine the overall thermal performance of the MDA simulated wall structure as a -Passive Thermal Control system under specified test conditions. The inner wall was main- tained at a constant temperature through regulation of an internal rndiant heater. The test article was allowed to come to steady stste conditions and temperature measurements were recorded on the pressure wall, the tnsu1ation surface and the meteoroid shield. The heater input was recorded and heat distribution through the walls analyzed. Thermal conductivity value of the insulation blanket was derived and recommended for use in the MDA flight thermal model to predict the insulation's part on the overall thermal perfol1nance of the MDA. The thermal conductivity was determined to be K = 0.000357 + .COOOl14T where K = BTU/hr-Ft-OF and T = temperature in of. The analytical techni-ques used for the MDA in simulating the various heat transfer paths (fiberglass rails, insulation blanket, lateral shorting via structural tees) were found adequate for predicting the distribution of heat transfer of the wall -structure and port structure. The test results thus provided useful data to predict thermal performance of proposed wall features and verified analytical techniques to be used in computer models of the goA. (1) Insulation Blanket Tests (a) Development Tests 2-181 .... • III Super-Insulation lil~~ket Pressure Drop Test - Flow rates of GNZ proportional to values specified in the eEI (5 lb/min +2, -1) uere run. through a 6 inch diameter simulated MDA insulation blunt,et sample in order to determine the pressure drop across the blant,et samllle. Test results indicated a pre'lsure drop of 0.004 psi for a flm~ corresponding to 5 lb/min. The test was completed 16 February 1970. III Flammability Test - The objective of the flamm- ability testing was to determine the conditions under which the insulation \'las flammable and hou much damage was incurred. II total of five tests were conducted. Three of these tests used a standard bunsen burner applying the flame for 12 seconds with dHferences in orientation (vertical vs horizontal) to the flame and mounting provision (blanket unmounted Vs blanket mounted on 1/4" plate). Departures from the above procedures were in the type of ignition used, in one case, a paraffin candle,and a match in the other. Results were evaluated on the basis of time to ignition, self extinguishing time, bu~ing rate and depth of burning. Results indica fed damage was greater where both sides of the blant,et were exposed (unmounted), flame was self-extinguishing when propagating downward and when the blanket was in a horizontal position with one side exposed with the metal plate under it. Packaging of the }IDA insulation blanket reduces flammability by minimizing convection currents, reducing air aupply for combustion and creation of a heat sintt by the aluminum pressure wall. (b) Qualification Test - No qualification tests Were per- formed on the insulation blanket as such. (c) Acceptance Test - The assembled insulation blankets were subjected to an acceptance test before they were installed on the MDA. Emissometer readings sh":1ed that the outboard sheet (5 mil aluminized mylar) had an average emissivity of not more than 0.07. This data was compared with design values to assure adequacy of actual insulation hardware installed in the flight article. (2) Fiberglass St~ndoff Tests (a) Development Tests " Fiberglass Rings and Rails " .~ 2-182 r·--· A series of tests to determine the thermal conductivity of a phenolic bonded fiberglass, CTL"91LD, were conducted at l'1}lC b"tween June 18 and July 6, 1970. Test samples ~~ere fabricated from 10 layers of fiberglass material, bonded with CTL"91lJ) ph,molic tesin. The £ibetglass cloth I~as otiented so that the heat flow 1.n the test specimens would be parsllel to ;;he fibers, as it is in the fabricated members that ate installed in the ~IDA. '.Cypieal membets are the ~IDA meteoroid shield support rails and rings. The thermal conductivity was determined to be K " 0.315 + 0.0068T whete K is thermal conductivity in B1'U/hr"ft"oF and T is average temperature in OF (T= "lSOop to OOF), (b) Qual Test" N/A (c) Acceptance Test " N/A (3) Low Emissivity Tape (a) Development Tesl; " Aluminized tape J462 ~,as designated to be applied at various ~IDA regions where the passive thermal control property of low emissivity ~~as required. Specimens of J462 aluminized tape were emissivity" measured as received, after fingerprinting, and after fingerprillting and clesning. Nethyl"ethyl ketone was used as the cleaning solvent. Seversl T2024"T3 aluminum alloy test specimens wete coated in aecoiaance with a standard MMC immersion process for cortosion protection and clUe specimen was il:ridited (brushwon process). The specimens processed by immersion for emissivity evaluation were much darker than usual and the tesults were con- sidered representative ¢f a "worse case" condition. The meteoroid shJ.'i!lds were fabticated from T2021,"T3 aluminum sheets. Followi.ng were the emissivity test results on the specimens measured on the Lion Nodel 2SA emissometet: Specimen ~ J462 aluminized tape (handled 1"lith gloves) " J462 aluminized tape fingerpril,ted G J462 aluminized tape fingerprinted and wiped with clean cloth o J462 aluminized tape, fingerprinted and wiped with solvent and cloth • !2024-!3, regular irridite, 3 min immersion • !2024-T3, brush-on irridite Emissivity 0.03 0.04 O.035~' 0.045* 0.14 .06 ,', !hird place figures were obtained by interpola ting between successive meter readings (b) Qualification !ests (N/A) (c) Acceptance Tests (N/A) (4) Exterior Coatings (a) Development !ests - Two exterior coating materials were chosen for application to the exterior of the MDA for thermal control purposes. 3M Nextel blael, velvet (401-C10) coating as measured in MMC's Materials Engineering Laboratory, using the Lion emissometer and reflectometer, had a normal emittance of 0,96 and an absorptance (solar) of 0.98. !his coating is used on exterior ourfaces of the MDA that are within line-of-sight to the S190 window. !he blael, coating applied on the meteoroid shield is Laminar X500 flat black polyurethane. Measured values were 0.92 for normal emittance and 0.95 for solar absorptance; (b) Qualification !ests (N/A) (c) Acceptance !ests (N/A) D. Mission Results - An indepth discussion and presentation of mission results is contained in Volumes I, Jr, and III of the "MDA Module Report" for 8L 1/2, 8L3 and 8L4, respectively (ED-2002- 1702). Included are detailed plots of all MDA data and selected AM data for the entire mission period. However, a summary of mission results follows: (1) Requirements vs Actual Rasults - Because of the close interaction between the Fassive and Active TC8, this summary of mission results includes reference to both systems. At various times during the SL 1/2, 8L3 and 8L4 missions, the MDA was operated differently than planned prior to the mission. Off-nominal operation included taking on a pitch attitude with increased solar exposure of the MDA, operation in a "Heater Management Mode" to con- serve electrical power, and extended operation in the ZLV attitude to accommodate lengthy EREP passes. During these "off-nominal" periods, some of the MDA requirements were exceeded. The unplanned pitch attitude and extended ZLV attitudes resulted in external meteo- roid shield temperatures exceeding upper limits. Operation of the wall heaters intermittently, in a heater management mode, resulted in the MDA exceeding low side limits during SL 1/2 and being lower than nominal for SL3 and SL4. Lower temperatures resulted in relative humidities that exceeded high side limits and operation outside of the comfort box on the low side. While the MDA periodically exceeded some limits throughout the mission, no detrimental effects on either the MDA, MDA equipment experiments, or the crew wer,~ noted because of it. When the MDA >Jas operated as planned, all parameters returned to normal limits with one minor exception. During temperature decay for the post 8L 1/2 orbital storage period, the local temperature near the 8190 window and 8191 experiment attained 38 degrees fahrenheit. (Minimum limit is 400 F). No detrimental effects were noted, and the temperature returned to 4loF after the heating system reached quasi-steady state conditions. . (2) On-orbit Passive TC8 Performance - The MDA insulation blanket, fiberglass structural supports, low emissivity tape, paint pattern and details of construction, all contributed toward insulating the vehicle internal structure from the external environment. Assessment as to the individual insulative effect of all these items for the on-orbit period was not possible. However, the overall effect of these items has been calculated. The MOA overboard heat loss thruthe vehicle structure was calculsted at 1401 Btu/hr when the MOA interior was at an average temperature of 59.60 F. A preflight estimate for the same internal temperature was predicted at 1285 Btu/hr. This was a maximum estimate and made under the assumptions of maximum wall conductance, coldest estimated orbital heating, and minimum radiator heat load. Thus the actual MDA heat loss was approxi- mately 9 percent greater than the maximum predicted loss. The effects of this on vehicle operation t~ere slight. Warmup from orbital storage temperature was slightly slower than anticipated in preflight estimates, and slightly more heater operation was required to keep the MDA at desired temperatures. The overall heat loss was well within the control capability of the MDA wall heating system. One area of concern prior to flight was the overboard heat loss of penetration heat leaks. The 8191 and 8192 experiments fall into this category. Maximum heat leak for each of these experiments was to be 40 Btu/hr. Preflight testing indicated that 8191 would lose about 85 Btu/hr. Preflight analysis, When matched with flight temperature measurements, indicated that 8192 losses were about 100 Btu/hr on orbit. While 8191 and 8192 heat 10ssE's exceeded mission preflight allotments, there appeared to be no detrimental effects. Local wall temperatures near 8192 and 8191 simpLy were a few degrees cooler than expected. (3) Insulation Purge 8ystem - The insulation purge system t~as turned on approximately 15 hours prior to launch and functioned satisfactorily until lift-off, when the purge was terminated. 2.186 E. Conclusions/Recommendations- (1) Performance of Passive TCS - In conclusion, mission results have indicated that the MDA passive system ade- quately functioned in spite of off-design demands on the system. Overall vehicle insulating features were adequate to allow the active system to control the ve- hicle internal temperatures when normal electrical power was available. (2) Instrumentation - Thermocouple placement on the MDA allowed for thorough monitoring of the MDA thermal performance. However, two recommendations are made concerning the instrumentation: The S190 window was closely monitored during the mission due to the possibility of moisture conden- sation on its internal surface. Many analyses were pel~formed to extrapolate measurement values from nelarby instrumentation in order to predict window temperatures. A temperature transducer, located on the internal surface of the window, would have eliminated much analysis and given accurate real time information. It is therefore recommended that future spacecraft windows, that are sensitive to temperature, be equipped with temFerature trans- ducers wherever possible. The axial docking port had two separate temperature transducers to monitor temperature. Shortly after launch, when the cluster was put in the pitch-Up attitude, the temperature transducers in the axial tunnel pegged out on the high side at lI30 F. Analyses had to be performed to estimate the true maximum temperature. It is, therefore, recommended that wherever there is redundant or dual ~.nstrumentation on future spacecraft, consideration be given toward making the calibration ranges different in order to allow for contingencies. (3) Analysis vs Test - The MDA thermal effort involved many analyses because of the desire to reduce expensive testing, In some cases, testing would have been less expensive, and would have provided more assurance of a successful product. One case involved an extensive analysis performed to pre- dict the ascent venting characteristics of the multilayer insulation blanket. This type of engineering problem does not lend itself well to an analysis. A t·ast could have been set up and conducted for a fraction of the cost to do the analysis. 2-187' It is recommended that future programs give careful con- sideration toward running brief tests as a potential cost savings to certain analysis tasks. F. Passive Thermal Control History - The MDA TCS design, con- ceived in 1968 preliminary design studies, incorporated a purely passive system which relied on a combination of wall insulation, radiative selective external coatings and internal atmospheric gas convection to maintain desired temperature levels. This system incorporated an inner pressure wall covered by a 27 layer high performance insulation blanket which in turn was covered by an aluminum meteoroid shield, thermally coated and supported by fiberglass structural standoffs. A design objective was to limit overboard heat lealt to approximately 250 BTU/Hr. Subsequent design studies supported by tests revealed that a degree of active temperature control in the form of wall heaters would be required to maintain a minimum temperature level during orbital stor- age periods. Further wall insulation studies during 1968 and 1969 re- vealed that MDA heat leak was in the order four times that originally estimated due to heat shorts in insulation blanket penetrations and fiberglass standoffs. The following discussion summarizes the principal design decisions and events in the development of principal components of the MDA passive TCS. (1) Insulation Blanket - The original 27 layer ~luminized mylar with foam spacers, while judged an adequate insulation thermally, was replaced with a 91 layer aluminized mylar blanket with nylon spacers. This change was initiated by MSFC in August 1969 in order to minimize a potential contami- nation problem with foam spacers. The 91 layer configuration was selected to maintain a consistent MDA wall structural configuration even though it provides a wide margin with respect to insulative qualities. The nylon net spacers were subsequently replaced with dacron June 1970, due to nylon's undesirable outgassing characteristics and dacron's superior insulative properties. Concurrent studies supported by testing on the MDA Comp~nent Test Article i~dicated that approximately 65% of wall heat losses could be attributed to heat shorts through insulation joints. The potential pro- blem of heat shorts through gaps at structural joints was met by close inspection of flight and backup articles during blanket installation with all questionable joints reworked prior to final inspection. (2) Fiberglass Structural Standoffs - The fiberglass standoffs were assessed -eaiiy in the program to be a potential source of overboard heat loss. The principal issue in the use of fiberglass standoffs was the thermal conductivity of the structural rings and rails. Tests run at MMC in 1969 revealed that actual thermal conductivity exceeded .... original estimates by a factor of three, resulting in an increase in heat leak assessments. Inspection of the ~IDA component test article (See Para. C-l) after tests reveal.ed shear failure of aluminum rivets due to high temperature extremes with the result that aluminum rivets were replaced by steel hi-10k fasteners. Analysis of standoff rings in November 1970 resulted in configuration modifications which reduced heat losses through the rings by 50%. The application of low emissivity tapes to fiber- glass standoffs to further r.cduce heat shorts is discussed in Para. (3). (3) Low Emissivity Tapes - Analysis of MDA heat losses through fiberglass structural standoffS, S191 and S192 closure angles and the L-band truss carried out during 1970 and 1971 revealed that significant improvement in heat loss could be obtained by judicious application of low emiSSivity tape. The application to fiberglass rings and rails was made to impede radiant heat exchange betl'men the MDA pressure l~all, fiberglass E,tandoffs, and meteoroid shield/ radiator surfaces. The L-band antenna truss heat loss was reduced by 50% by winding all truss members with tape. (4) External Coatings - Parametric studies were carried out during 1968 in order to form a basis for selection of an exterior coating for the MDA meteoroid shield. These studies resulted in the selection of a black paint with properties of solar absorptivity to IR emissivity ratio ( Q! / t) of .95/.86. The selection was made on the basiS of minimizing heat loss, limiting external temperatures (-1800 to +2770F) and the stability of property values under long term space environments. This selection was carried forward to'the flight article with the exception of a circular white stripe added to the cone area in late 1970 to provide better visibility for doclting. The overall effect of this stripe was judged minimal to the MOA heat balance. (5) Insulation Purge System - A dry nitrogen purge requirement l~as established in early 1968 in order to assure that the MDA external insulation was free of moisture prior to launch. A preliminary study was made at MSFC which defined the aystem performance reqUirements. Final performance requirements were established and a design definition made • t 2.2.3.2 ~ctive System A. Design Requirements and Analyses - Design Requirements for the active system are indicated in Table& 2.2.3-1, 2.2.3-2, and 2.2.3-3. As indicated before, an "A" or "B" indicated for each requirement deSignates whether the requirement is applicable to the Active TCS or both the Active and Passive TCS. Table 2.2.3-5 lists the performed for the active TCS. in the followIng paragraphs: categories of analysis and studies Thes~ are discussed in further detail (1) MDA Vehicle Computer Models - The MDA computer models consisted of three separate model systems; 1) an MDA heat flux model to obtain external environmental heating, (2) an MDA external thermal model to compute extetnal temperatures, and 3) an ~IDA internal thermal model.to compute internal temperatures. The case studies with the MDA math model systems were used for numerous purposes in evaluation of active system performance. Included were the following: (a) Effect of Equipment on the Active System - Included was the effect of H512, EREP, BILCA and other internal heat generators on the Active TCS. The Active TCS l;aS investigated for ability to handle the imposed heat loads. (b) Effect of heat generating equipment on nearby equip- ment. (Such as effect of M512 on the ATM film vaults). (c) Thermal performance and internal }IDA temperatures due to operation of the Active TCS and MDA internal equip- ment. This included orbital storage cool-down and warmup transients as well as manned mission period operation. (2) MDA Wall Heating System (a) Pteliminary Studies - A ttade study consideting fout thermostat systems was petfotmed to establish the thermostat configuration to be used fot the opetation of the MDA wall heatets. (1) MDA Vehicle Compute~ Models (a) Effect of Equipment on Active System (b) Effect of Heat Generating Equipment on Other Equipment (c) Thermal Pe~fo~ance and Inte~nal MDA Temperatures (2) MDA Wal.l Heating System, Analysis & Studies (a) Preliminary Studies (b) Design Studies (c) Final Design Studies to Establish Performance (d) failure Analysis (e) Test !lupport Studies (3) MDA Docking Port Internal Heating System Analysis & Studies (If) MDA Axial Docking Tunnel Heating System Analysis and 8tudies (a) Dockil':g Port Temperature Prior to Adding Heaters (b) Design Studies (c) Final Design Analysis to Establish Performance (d) Failure Analysis (5) S190 Window Heating System (a) Conceptual Studies (b) Design Analysis (c) Performance Evaluation (d) Test Support Analysis (e) Failure Analysis Table 2.2.3~5 Active MDA TCS Analyses 2-191 (b) Design Studies - Calcuiations we,re made to evaluate the wall heater mounting location and establish the design features for their installation, for most efficient heat transfer into the wall. Analysis ,qas also performod to establish the thermostat location. These analysis gave consideration to thermal con- ductive filler application between the mounting interfaces. These studies involved computer calcula- tions for each item being studied. (c) Final Design Studies to Establish Performance - These studies were made to establish the MDA interior temperature de'ltas, heat lealts and heater performance regarding warm-up times for selected cases. Computer models for this included an overall MDA Interior Model (supported by external models) and wall section models. Calculations were made to predict the maximum number of Thermostat cycles during operating periods to insure operation within specified limits. (d) Failure Analyses - In support of manufacturing operations, a study was performed to determine effect of revision (e) to the~mostat specification regarding set points. Relaxing the criteria permitted reducing the rejection of units at acceptance tes t. Thermal analysis of the wall heater wid,ng, in con- junction with stress analysis and an evaluation of test data, were employed in lieu of a qualitative life cycle test to e1:i,minate concern of a thermal fatigue failure mode. Test Support Studies - System verification test data was analyzed to verify proper installation of the wall heaters and proper operation of the wall heater control. Previous data from computer math models was employed for comparison. (3) lIDA Docking Port Internal Heating System - 'The MDA Internal Thermal Model included representation of the Radial and Axial Docking port ring heaters. Studies using this model have included performance of these heaters. (4) MDA Aldal Docking Tunnel Heating System I .. ~; (a) Preliminary Studies M These analyses were performed to establish docking port temperatures prior to and after docking. It was determined that heaters would be required to llarm up the surfaces. Computer case studies were utiHzed. (b) Design Studies M Analyses involving a range of heater sizes were performed to select' the heater capacity to provide reasonable warmMup after docking. Computer math models of 'undocIted' and doclted CSM/~IDA configuraM tions were utilized to predict temperatures. (c) Final Design Analyses to Establish Performance M Further analyses was performed after selection of heater size to determine cycle rates in conjunction with thermostat settings in order to insure the control relay would operate within its specified limits. Thermostat set point evaluation and thermoM stat cycle rate analysis were performed to determine proper operation of the thermostat. (d) Failure AnalysiS M A thermal analysis was conducted in order to predict maximum temperatures in the docking port area in the event of runaway tunnel heater cond i tions. (5) S190 Window Heating System - Several, types of the;:m~l analysis were required to design, analyze. and test the S190 window heating system. The snalyses fall into the following general categorie3: • Conceptual Studies • Design AnalysiS e Performance Evaluation 9 Test Support AnalysiS • Failure Analysis (a) Conceptual Studies M The objective of these studies was to establish an optimum thermal control design that ~{ould satisfy all window requirements. Trade studies investigated nineteen thermal control designs involving both passive and active controls. The following thermal control techniques were cunsidered in some combination with one. two. and three pane window configurations: • fana with atmosphere heaters • glass surface conductive heaters • glass surface electrical conductive film heaters • radiant heaters • fans ~~ith no atmosphere heaters e no active heating provisions Host of these designs required thermal math models and computer analysis to calculate thermal perfIJrmance. (b) Design Analysis - The design analysis objective was to calculate ~~indow pane temperatures and temperature gradients as affected by the heater control system design. The t,intio\V pane tempera tures and gradients m~re calculated for the eKternal radi:mt heater design and the Electrical Conductive Film (ECF) heatel:' design. Selection of the ECF heater design resulted in analyzing the ambient reference sensor for optimum locations and temperature bias. The control system \Vas analyzed for its affect upon MDA wall and atmosphere tempera tU'r.es. Haximurn control bOK temperatures and maKimum wire temperatures were calculated to assess impact on touch temperature limits. All the proeceding analysis required detailed thermal math model development and computer analysis. (c) Performance Evaluation - The window thermal perfor- mance was predicted so that various EREP passes could be evaluated for optical performance. The baseline EREP passes were analyzed for the worst case pass. For this pass window pane temperature maps and tempera- ture gradients were generated. The temperature maps were input to optical group for window optical perfor- mance evaluation. EKtended duration EREP passes, night EREP passes and terminator EREP passes were evaluated. Basel~ne passes were evaluated with the window heater controller turned off. All of these performance evaluations required computer runs using detailed thermal moth models. (d) Test Support Analysis - Two test set ups were analyzed, full scale external radiant heaters and electrical conductive film (ECF) heater development test. The eKternal radiant heater test analysis was used to predict the test article thermal perfor- mance during the simulated flight environment test. Z-194 \ ) The ECF test a~ticle analysis was used to evaluate the window test the~mal pe~fo~mance and COI"pa~e it with the p~edicted flight the~mal pC~fOL1nance. All analyses ~equi~ed theU,lal ma ttl models and computer studies. (e) Failu~e Analysis - Compute~ math models of the window we~e used to predict ares temperatu~es and window glass temperatU1:e g~adients in the event of windtlw frame heate~ and/o~ windoli glass heater failu~e fo~ va~ious ope~ating conditions. B. Functional Description - P~ima~y items in the MDA active system included electrical and ECS ha~dware. Elect~ical ha~dwa~e consisted of heating systems fo·;: the MDA wall,. interl1.al do cIting port areas, and the axial docking port tunnel. During pe~iods of low inte~tkil heat generation, the thermost- atically controlled MDA heater systems provided heat to allow the MDA to meet specified tempe~atu~e limits. During manned wission periods, the MDA plans we~e b~ set the heaters fo~ the 70 F control mode. Du~ing o~bital storage, plans we~e to use a 450 F control mode fo~ the MDA inte~io~. Du~ing manned mission modes and periods of high internal heat generation, the MDA heating systems were inactive due to thermostat cut out. Cooling was p~ovided by introducing cooled air ·from the AM via the ECS ducts. The cabin fans were used to p~ovide satisfactory atmosphe~e "i~C\ila tion and velocities a t crew stat:i,c;ns. " (1) MDA Wall Heater System - The wall heating system was pa~t of the Active TCS, Figure 2.2.3-7 depicts the Active TCS. Forward Wall Tunnel .Inlernal Port S190 Window Healers Wall Healers Sieve DUc! C&DIEREP Loop Ducls (3) Figure 2.2.3-7 Active Thermal Control System .Schematic 2-195 Eight 20wwatt and eight 40w watt wall heaters were located in the interior barrel section of the MDA pressure shell to heat the MDA. Each heate·r had a primary and secondary (redundant) heater element. An overtemperature thermostat l~as electrically in series with each heater element. Four (4) wall heater, 700 F thermostats and four (4) wall heater, 4SoF thermo w stats were provided to control the internal temperature during manned and unmanned flights respectively. Each thermostat had a primary and secondary (redundant) set of points. A general arrangement of the wall heater system is ShOl~;l in Figure 2.2.3w 8. A typical installation of two wall heaters and one thermostat is shown in Figure 2.2.3w 9. Further information concerning the wall heaters arid thermostats is contained in the Electrical Subsystem, Paragraph 2.2.4 of this report. ~1 ~PJ ~l ~2 ~~~2 O Docking Port I nternal Heater. Docking Port Tunnel r:==~r~Heater. 160 Watts ,; Docking Port Internal 15 Watts Heater 15 Watts Wall Heaters 20 Watts Each Wall Heaters 40 Wall, Each Wall Heater Thermostat Settings Each Thermostat System m Controls 4 Wall lieaters Manned Operation 66.5"F to 73.5"F Orbital storage 42"F to 50"F Figure 2.2.3~8 Wall Heating System, General Arrangement I I ... · . Figure 2.2.3-9 Wall Heacer and Thermostat, Typical Installation (2) MDA Docking Port Internal Heating System - Each docking port had a IS-watt heater to make up the heat lost through the docking port . Each heater had a primary and secondary (redundant) heater element. An over- temperature thern.ostat was electrically in series with each heater element. Each heater circuit had an inline thermostat' to control the docking port temperature to between 60D? and 70oF. Each thermostat had primary and secondary (redundant) contact points. A typical docking port heater installation is shQwn in Figure 2.2.3-9. Further information concerning the heater system components is found in the Electrical SubsYRtem, Paragraph 2.2.4 of this report • ... 2-197 r (3) MDA Axial Docking Tunnel Heating System - lvo (2) semi-circular 80-watt strip heaters ~ere installed around the external surface of the axial port docking u lnnel. Each heater had a primary and secondary (redundant) heater element. Th£ system was used to provide a shirt sleeve environment for crew entry into the docking tunnel. In addition, it assisted in overall vehicle thermal control during orbital storage and manned mission modes. An overtemperature th~ rmo stat was electrically in series wit!. each heater element. Two (2) thermostats were provided to control the temperature of the axial port tunnel to between 600 F a~d 74oF. Each thermostat had primary and secondary (redundant) contact poin t,. A photograph of the axial docking tunnel heating system is shown in Figure 2.2.3-10. Further informa- tion on the system may be found i n the Electrical Sub- system, Paragr~ph 2. 2.4 of this report . Figure 2.2.3-10 Docking Tunnel Heating System 2-198 ") I (4) MDA EREP S-190 Window Heating Sys tem - The S-190 Window Heating System contain d a window, electrical cable and heater controller subassemblies as depicted in Figure 2. 2.3-11. The function of the window hea ting system was to contro l the window temperature s such that the glabd temperature gradient s were minimized and moisture condensation was prevented . 5190 WINDOW CONTROLLER I • Figure 2 . 2 . 3-11 5190 Wind ow Heating 5y.tem The window subassembly contained a 40-wa tt electrical conductive ~_lm heater on the glass outer surface. Two 100-w~tt frame henters were mounted in the glnss support frame . Th~se three heaters contained a total of four t eldperature sensors for hea ting control and three sensors for overtemperature . C. Test - Active Thermal Control SYR t em component development, qualifica t ion and acceptance t ests are repo r t ed in thi s section of the report . Those tests performed as a functi on of MDA module level sys t em testing are r eported in Paragraph 7.8. Failures that occurred during all tes t i ng, i ncluding system level tes t ing, will be reported in this sec t lon. 2- 199 (1) ~IDA Nall Heater System Testing (a) Wall Heaters" HSFC pIN 20H42245-17 and 20H4·2245-19. These were GFP components. Compon" ent testing of these items is not included in this report. (b) Wall Heater Thermostat " ~mc pIN PD7400083 • Development Tests " Not required. Simplicity of device precluded development tests. • Qualification Test " AETL. Report No. 5350-00-9171 - Qualification testing on the thermostat assamblies was completed on 16 November 1971. Two thermostat assemblies l~ere subjected to the follmqing qualifi- cation tests: Vibration, consisting of sine evalua- tion, vehicle dynamics, high and lmq level random, shock, thermal vacuum, t::.mperature. aLtitude, storage and transportation, snd CCOH. A performance test IqaS conducted prior to and after each environ- mental test. The performance tests consisted of a thermal sl: controller assembly thermal qualification tests are contained in Actron Report No. HWS-190-DI-9-2 and consist of the following tests • I· - F~e-Qualification Acceptance Test which we~e: Senso~ Tempe~ature Test, Temperatu~e Control Test (System Level). Over-temperature Test (System Level) and Delta Temperature Test (System Level). ~ Qualification Tests which were: Low-Temperature Storage Test, I!igh~Temperatu~e Sto~age Test. Random Vib~ation Test, Complex WDve Shock Test, and Co~~osive Contam~nsnts. Oxygen, and Humidity (CCOH). - Fost-Qualification Tests which were: Temperature Cont~ol Test (System Level). Over-temperature Test (System Level) and Delta Temperature Test (System Level). The thermal qualification tests on the control cable and heater controller encountered no significsnt thermal problems. S190 Window Heater Controller was 2 DB out of specification for EMC Qualification testing. A waiver was granted since slight deviation presented no problem. technically. for the MDA system. A delta qualification test was performed on the heater controller in March 1973. Resutts of the test are contained in Actron Report No. ETI. (R) - 73-002. The tests performed were to establish thermal deltas and maximum temperatures reached on components anlt areas of the Heater Controller Case when operated under various load and electrical characteristics when the unit was subjected to the following test conditions: • 0.1 PSIA atmosphere environment at a mean thermal ambient temperature of 70DF • • 0.1 PSIA atmosphere environment at a mean temperature of SOoF. In addition, the tests evaluated the thermal efficiency of heat sinks. added to areas of the heater controller containing components with high thermal outputs during nOJ:llllll operation. (c) Acceptance Tests - The window. control cable and heater-controlle~ assemblies acceptance tcsts did not contai,n nny thcrmal type tests. All tests were of an electrical. structural, and optical nature. The System Level acccptance tests did contain the foJ.lowing thermal tests: • Temperature Control Test • Over-temperaturc Test 6 Temperature Test These thermal acceptance tests were conducted on the flight and bacltup window articles and no problem areas were found. A thermovision test was run on the backup and qualification windows and the report indicated no thermal di~crepancies during these tests. (d) MDA EEEP S190 Window Heater Control System Testing Failures - DU:L'ing testing of the flight MDA at St. Lonis and KSC a single point ground violation occurred in the 8190 Window Heater Controller. Failure analysis revealed that defective internal feed-through capacitors were the cause of the failure. All controller units were reworked. Another failura occurred at St. Louis during MDA testing of the Window Heater Controller system. The controller cable shorted out one of the con- troller sensors. A redesign of the cable corrected this anomaly. D. Mission Results - An in-depth discussion and presentation of mission results is contained in Volumes I, II, and III of the "MDA Module Report" for SL-l/2, SL3, and SL4, respectively (ED 2002- 1102). Inclnded are detailed plots of all MDA data and selected AM data for the entire mission period. However, a summary of mission results for the Active Thermal System follows: (1) Requirements vs Actual Results - Because of the inter- action between the MDA Active and passive TC8, require- nents and results are discussed under the Passive TCS. (2) Hardware Performance - (a) Hall Heater Operation and Thermostat Control - During SL-l/2', due to high equipm('nt I~ns prov!de>d throllr,h the> utility outl('.t to structure. Each uti lity out ll't contained an ON/OIll;' SI~ltch nnd n zero~g connector I~hich inted'aced I~ith the portable equipment cable connectors. " (2) High Power Accessory Outi~t" - Two 12--amp h!~h poW~r aCCeR"(1ry outlets (Sec .·I~un' 2.2.4-1) prov j dC'd 2H v(k pow'-'r to portah h· ('(111 f pmC'nl ~ pllOlugrllphic cqtl ~ pi1lcnl, {'xpcrilll('ntR nnd UR' 'rv Video 'rA pe Il('<." o rder . The outlels wcr~ locntcd at each e'1 Pyro Shock • EHI • Thermal Vacuum • Temperature, Altitude, Storage, Transportation N I N N .... Base Assembly Relay Mounting Frame ~-r- Terminal Board ~~ Assemblies "'--Plug Figure 2.2.4-2 Power Distributor Assembly ..... T A performance test was conducted prior to and after each environmental test. Units tested were pIN 82000000900~009. The ~010 and 82000009100-010 were qualified by simi- larity, (b) The PDAs did not comply with the EMI require- ments of MIL-STD-46lA. DAR-MDA-5 was sub- mitted and approved. The conformance was of short duration and infrequent and resulted in no system performance degradation. (3) Acceptance Tests - Each FDA was subjected to an Acceptance Test per 82000000900 O~ 125. The Acceptance Tests were conducted pre and post vibration using the AT506640 FDA test tool. (4) System Tests - During the system testing, the FDAs were used to distribute power to the MDA heaters and lights and satisfied all requirements of the flight and backup STACR. One PDA.filed the MDA single point ground if-ola- tion test on the flight article at St. Louis. Failure analysis was performen Ctnd a bead of solder was found short-circuiting a relay case to the power return. A discrepancy check and report was run on all units, the acceptance test procedure was changed and the hardware was repaired. There ~~ere no further PDA failures. D. Mission Results - The FDAs performed satisfactorily during all Skylab missions. E. Conclusions and Recommendations - The FDAs performed satisfactorily and met all design requirements. 2.2.4.3 Cable Assemblies The MDA electrical cabling construction consisted of ~~o types: (1) those cabl.es used inside the MDA; and, (2) the exter- ior cables. The interior cabling was designed and constructed to include flammability protection, and was installed in covered cable trays to provide protection against cable damage, see Figure 2.2.4-3. The exterior cabling configuration was the same as the 2-222 ) '. • • • o Figure 2.2.4- 3 MDA Interior Cabling 2-223 interior design, ."ith the exception of fldmmability protection and c~ble tray installation. The exterior cables were installed on the MDA structure and mounted under the meteoroid shield, see Figure 2.2.4-4. The L-Band truss cable" being e~terior of the Meteoroid shield were wrapped in NBG material for meteoroid protection . Figure 2.2.4- 4 MDA Exterior Cabling Mismating protection of similar connectors was accomplished by the use of identification tags, connector clocking, cable routing and clamping. 2- 224 1 A. Design Requirements - ~IW;; drawings that I~ere applicable to ~IDA cabling deSign, fabrication and testing I~ere: • 82000000304 • 82000000401 • 82000000503 • 82000000603 • 82000000713 Automated lnring Diagram Electrical Schematics Coble/Component Installation-Interior Cable/Component Installation-Exterior }IDA Cabling Interconnect Diagrams The }IDA electrical cabling consisted of stranded and coax I~ir~. The standard wire types I~eru identified by NHC material specifications snm 843, 921 and 922. The wire was constructad of a polyimide coated teflon insulation over a silver plated copper conductor. The shield jacket I~as extruded teflon. The wire conformed to HIL-H-22759. The coax I~ire types I~ere as follows: ~mro material code E1300153 (RG179/U) - Teflon dielec- tric ~dth a 30 awg silver plated center conductor - silvered copper braid with an extruded teflon outer jacket. This cable conformed to HIL-C-17 and I~as a 75 ohm coaxial cable. }IHC material code 411700001 triaxial cable had the same materials and the same performance characteristics as the 75 olun coax cable above. The connectors used throughout the ~IDA I~ere in general accordance with HIL-C-39012, NSFC 40H39569, HSFC40H39580, V56- 421102-11, V56-53ll03-21 and NHC dral~ings ST81D78, ST8lD88, ST8lD89, ST8lD107, ST8lD108, ST6lDllO, ST82D28, ST82D29 and ST82D32. See Figure 2.2.4-5 for examples of coax connectors ST82D28, ST82D29 and ST82D32; zero-g connector 40H39580; A1>1 interface connector ST81D108; and feedthrough connector ST8lD107. Feedthrough connectors were used to provide hermetically sealed sldn penetrations capable of transferring elel·tricnl sig- nals and pOI~er through the }IDA sldn. These connectors consisted of various types: Deutsch Series 46000, pin to pin (minor image) used ~!ith NAS 1599 (lf0H39569) plugs; Deutsch Series 22638-24- 100-PP for coaxial penetrations used I~ith Deutsch 38134-24- 100SN Plugs; and Hicrodot/Airlock hermetic receptacl(,1 (GFP) for crel~ handling functions used with Hicrodot/ Airloclt Plugs (GFP). All of these connectors are single hole mount and were installed prior to any leak checks performed on the ~IDA. Protective covers were installed at all times prior to harness installations. 2-225 ~~I'4itM •. f~ (' .. ' '.' 5T810107 Figura 2.2.4-5 MDA Electrical Connectors The development mockup, ,~hich started out as a 1800 shell and ,ms modified into a full 3600 mockup, was usad as a high fidelity structure to design and develc,p the flight elactrical. harnass configuration for both tha internal anrl, external cables. It provided information in regard to bundle ~ize, optimum bundla routing radundancy and EHC category separation, determination of clamping provisions, location and oriantation of connector brack- etry, design and development of cable trays, as well as cable tray covers. It ,~as also used to: develop cab le flexing methods for cables routed to shock mounted or moveable componants; verify the cable forces on those particular components where necessary; locate shield terminations and ground studs for structural grounding; and finalize cable fl.ammability protection, processes, and quantities. It ,~as later used as a three dimensional tool for fabrication of the internal flight and bacl,up harness. The L-Band cables ,~ere also dave loped on a thrae-dimansional tool ,~hich sarvad its purpose in the same capacity as the develop- mant mockup. Connactor identification tags ,~ere pOSitioned such that they could be read ,~ithout: twisting the cables or disconnact- ing the connector. 2-226 Cables terminating in a Zero"G connector \,ere potted for strain relief and fitted with a flame proof piece of convoluted tubing extending from the rear of the connector through the first cable clamp. This was done to give the cre\, the same handling characteristics of these connectors ill the MDA as they would experience throughout the cluster. See Figure 2.2.4"6. Fluorinated Hydrocarbon Harness to Connector Adapter Zero"G Connector to Cable Boot Figure 2.2.4-6 Termination of Zero-G Connecto~ Physical damage protection of the interior harness was provided through the maximum use of cable trays, cable covers, ducting, routing techniques and sleeving. Flammability protection of the MDA cable assemblies was in accordance \,ith MSFC-SPEC-lOIA. Cables ~,ere completely enclosed in fluorel coated fiberglass tubing. Tubing junctions and cable -junctions were formed-as shOlm in Figures 2.2.4-7 and -8. The backup article tubing junctions were improved for handling and dressing by use of a telescoping method with a string tie in lieu of the Butt Junction. To complete the enclosure at the connector ends, fluorel coated fiberglass, teflon coated fiberglass, convo- luted viton tubing, fluorinated hydrocarbon boot, or approved combinations of these were utilized. See Figures 2.2.4-9 and 2.2.4-10. "I--Tubing overlapping Tubing Figure 2.2.4-7 Tubing Junctions r- OVerlapping Tubing ~ 1 < 11=:::::----.::::::..;:-,.....-_-~T-u-biJ-n-=g<-lJ string Tie=:7 "Y" Type Breakout Joint Figure 2.2.4-8 Cable Junctions 2-228 . I 'i A Materials A Teflon Coated Fiberglass Cloth (Used to Make Flameproof Covers for Areas Not Covered by Tubing. Covers Are Called Beta Bags). B Ftuorel Coated Fiberglass Tubing - 3 It Lengths C Liquid Fluorel Overcoatlng Material for Sealing Raw Edges of Tubing and for Sealing of Taped Junctions . o Fiberglass Tape - 112 and 1 Inch Wide - No Adhesive E Fluorinated Hydrocarbon Harness to Connector Adapters Figure 2.2.4-9 Cable Flammability Protection I nstalied Beta Bag Figure 2.2.4~lO Cable to Connector Flammability Protection 2-229 1 D. Functional Dcscription ~ Thc HDA Electrical cabling pro~ vidcd thc follm~ing functions: interconnection of various elec- trical subsystems ,~ithin the ~IDA itself; and pO\~er Ulld signals transfer betl~een equipment and subsystems located I~ithin thc }IDA and other cluster modules. The contingency cables for the video sl~itch pOI~er and the video loop hook-up, NNC dra'~ing 82000042920, ,~ero designed, built, and tested to thc samc criteria as the flight functional cables, and s tm~ed in the ~IDA. The DI/LeA cabling system was a mod Idt consisi;ing of cable harness, patch panel and 8 shorting plugs. The mod kit I~as designed to be incorporated with minimal effect or rel~ork on the e~isting ~IDA cabling. Proper selection and installation of (4) shorting plugs determined ,~hether the I/LeA or DI/LeA system operatcd. Installation of the mod kit, on the flight article I~as accomplished at St. Louis and functionally testcd and verified at l~C. C. Test ~ Continuity and megger testing of all hal"l1ess wire I~as done prior to pm~er application. Testing ,~as perfol"ll1ed after hUl:ness removal from the development unit and again after installa- tion on the flight article. The same test procedure mlS used on the harness for the backup unit. The test I~as accomplished using the Hughes Analyzer and was tested to 1500 VDC breakdo,m and 50 megohm isolation criteria. NOTE: Requirement to moet the 1500 VDC breakdmm testing was directed by NSFC. Ref: NASA letter PH-Sr,..AL/NDA-14Gl-70. The r,..Dand cables I~ero subjected to the sallie 1500 VDC breait- dmm and 50 ulogohm isolation testing. Additional test activities resulting from design changes and connector problems were as follo,~s: C" ) .... Hicrodot/Airloclt connector tolerance buildup; (NASA Alert 72-03), brought about the des ign and fabrica- tion of test equipment to test all the affected connectors throughout the cluster. Structural ground continuity ou the doclting port heaters ,ms fOu\ld inadequate on the backup art icle, This resulted in additional grounding '~ires being added to both the backup and the flight Ill:ticle, ", I (3) Isolation of and/or crC\~ handling requireulents of coa~ connectors ST82D28, STB2D29, and ST82D32 pre~ vcnted safety wiring of receptacles and/or plugs. Vibration testing I~as performed on affected connec~ tors to determine the required torque values for mounting the receptacles, as well as for the nIllting of the plugs. NOTE: The incorporation of any and all mads into t'iiC~IDA vehicle resulted in the retesting (cantin~ uity and megger) of all affected cables and connec~ tors. This I~as effective at Denver, St. Louis and KSC. D. ~Ussion Results ~ The ~IDA Electrical cabling, having been designed, constructed and finished in a quality manner consistent I~ith manned space flight operations, demonstrated its integrity throughout all the Sl,ylab missions. E. Conclusions and Recommendations ~ The ~IDA Electrical Cabling System performed satisfactorily. An evaluation of bIDA connectors I~as performed as part of the postflinht data analysiS and crel~ debriefings. The results were that all bIDA connectors (NB, Hicro~dot Airlock and Zero~G) I~ere functional in space environ~ ments. For in-flight nIllting and demnting the crel~ e~l?ressed a preference for both the ~Ucro~dot and Zero-G connectors. 'rhe crel~ also suggested that in future space applications the in-flight nIllint .. nance connectors should be standardized throughout the spacecraft. 2.2.4.4 Interior Lighting The ~IDA Interior Lighting system (see Figure 2.2.4"11) was designed to provide illumination at the crew I~orl, stations and for general illumination of the ~IDA using the General Illumination Floodlight Assemblies. A. Design Requirements - The deSign requirements for the ~IDA lighting system were defined in C1'1l4A1000026 - ~IDA Contract End Item Specification. The basic requirements I~ere as follol~s: (1) General Illumination System - • An illumination level of 3.5 foot~cand1e (fc) minimum along the lt~aKis of the bIDA 2-231 • A minimum of 5 fc illumination at th work station nd onsol 8. • Lights n ar th ATM C&D Pan 1 w r r quir d to hav variabl illumin tion with maximum of 90X i11umin tion. • Th lights we ' to b controll d individu lly at th light a w 11 r mot ly from th A}1. • All lights w re to b simult n ous ly controll d from th axial do king port. (2) Em rg ncy Illumin tion Syst m - • Automatically con troll d and pow r d from AM. • An i11umin tion 1 vel of 0.5 f c to 2.0 fc along th X- axis of th IDA. • Lights to com on utomatically wh n AM bus vo1t- ag falls b low 23 VDC. Figur 2.2.4- 11 IDA Int rior Lighting Syst 2-232 AvI.tlon Red Strip Emergency Ughts Onl (3) The Light Assembly and the Light Switch Assembly (see Figure 2.2.4-12) were developed to meet the overall sys- tem requirements. The specific design requirements of the units were as follows: (a) Light Assembly (P/N lB69364) - This unit was supplied to the MDA as GFP equipment. It met the specificacion lB69364 written by MDAC-W. The requirements of the specification are as follows: - • Assembly shall be hermetically sealed. • All sWitching devices shall be hermetically sealed. • The power shall not ,exceed 12.5 watts at 28 VDC. • Each assembly shall have a local control of "OFF", "riM". and "HIGH". • Minimum operating life of 4500 hours. ,--':":::.- .. -- ~- - ._-"'"- - :::-.::. '" . , INTERIOR LIGHTS ON Figure 2.2.4-12 MDA Interior Light Switch Assembly (b) Light S,~itch Assembly (PIN 82000001800-009) M The u.lit was designed and fabricated at NMC. It met the requirements of the equipment specifica- tion, 82000001816. Some of the more pertinent of these are listed belm~: • Two pole-three position switch (momentary- maintain-momentary). It Contact :.'ating of 10 amperes at 28 VDC. • Voltage to unit of 28 !~ VDC. • Operating life of 10,000 cycles and storage life of three years. B. Funccional Description - The interior general illumina- tion floodlight assemblies provided crew work station illumination. There were eight interior floodlight assemblies, four on the for- ward dome and four aft along the air ducts. Each of the eight lights had a local sl~itching capability of "OFF", "ta;~" and ''HIGH''. Each light had an output of 315 lumens minimum before installp.titin into the light fixture. A switch (Panel 101) for On-Off lighting control for all eight lights simultaneously shall be provided near the axial docking port of the MDA for easy access control during astronaut engry. However. the individual light switches had to b\~ in either the "HIGH" or "ta;~" position for proper operation. The. MDA Lighting Control System was deSigned such that all AM remote control switches (STS Panel 207) were independent of each other and functioned in pairs of two lights per control. Control power switching of the ~ights was accomplished through latching relays in the PDAs (82000u;;0900-010). The two lightB above the ATM CW Panel (Aft 3 and Aft 4) were provided with removeable and adjustable light filters for the purpose of attenuating illuminati"n levels at the ATM CW panel. Two lights (Fonmrd 2 and Aft 3) functioned a3 emergency lights and I~ere controlled from the AM.· C. Test . (1) Development Tests - The number of lights in the }IDA and their location was determined by simulating the flight light output with commercial fluorescent lights and then conducting illumination tests in the MDA Engineering Mockup Unit (~~). Evaluation included: • Mechanical Characteristics • Electrical Characteristics • Performance Characteristics 2-234 Each Light Switch Assembly was acccptance tested at MMC for verification of the following: • Physical Examination • Functional Test • Vibr.ation. Low Level (2) Qualification Test (a) Light As~embly - The qualification testing for the Light Assembly was accomplished by MIlAC-\~. (b) Light Switch Assembly - The Light Switch Assem- bly was qualified by MHC. The results are con- tained in ~n1C Qualification Test Report No. 3178. All reqUirements were successfully met except forEHI. The EHI testing was completed in conjunction with the Power Distribut.or Assemhly, see Paragraph 2.2.4.2 C(2)(b) for EHI waiver infonnation. The qualification test covered the following: • Performance • Vibration • Thermal Vacuum • CCOH (Corrosion Prevention Criteria) • Shock • Temperature. Altitude. Storage and Transportation (3) Acceptance Test - Acceptance tests we~e completed by Sylvania Corporation (MIlAC-W's vendor) and con- sisted of: o Functional Verification o Hechanical Verification (dimensional analysis) o Illumination Verification (4) Lighting System Functional Verification (a) Denver - After installation of the lighting sys- tem in the MIlA. functional verification and illumination level tests were performed to pro- cedure HDA-OCP-D-60002 "EJ.ectrical System Functional". During functional verification testing of the individual light assemblies, two lights drew excessive current in the "LOW" mode. The lights were removed and replaced with flight spares. The removed lights were then re- turned to MDAC"W for failure analysis and modi- fication. The remaining functional verification tests were completed satisfactorily. TIle illum" ination level test was completed successfully except. for the ATM COD Panel and Aft General Illumination. (b) St. Louis - A functional verification test of the individual light assemblies was accomplished at St. Louis as part of the PDA reverification test (refer Paragraph 2.2.4.2 C(4). During this test, one light exhibited the same malfunction as the two in Denver. The light was replaced and retumed to MDAC...w. Dudng SEDR D3"E72 , "Systems Assurance". an illumination test was conducted. The illumination level at the ATM COD panel was again below specification. The decision was made to have a crew evaluation of the lighting during SEDR D3-E76. This was acco~ plished along with a remeasurement of the illum" ation level on the ATM COD panel. TIle crel~ evaluation indicated that the lighting was low but adequate. The illumination measurement met the specificat:!.on at the ATH COD, it was deter_ mined that the light meter was very sensitive as to where it l~as pointing which could have been the reason for the previous measurements not meeting the specification. Prior to altitude chamber testing, all MDA interior lights were replaced with modified lights received from }IDAC"H. The electronics of the lights had been mocified as a result of the failure analysis perb'l:1Iled by MDAC...w. Remaining tests were com- pleted satisfactorily. D. Mission Results - The MDA interior lights functioned pro- perly during S~2. During the S~3 flight on DOY 232, the Aft 2 and 4 MDA lights were reported out by the crew. The light assemblies were replaced and switches cycled, but the lights would not come on. Possible causes of the failure could have been an intermittent 'Aft 2·4' light switch on STS Panel 207, inadvertent operation by the crew. or an intermittent relay in an }IDA power distributor. 2-236 Trouble shooting procedures tvere accomplished by the crew on DOY 243. The crew complet(!d the first three steps of the procedure and reported that Aft Lights 2 and 4 were "ON" and that the switch on STS panel was intermittent. To preclude any further loss of Aft 2 and 4 lights, the lights tvere controlled from their local switches instead of the switch on Panel 207. To prevent operation of the light circuit in question during deactivation of SL-3 and activation of SL-4, the SL-3 crew opened the "~IDA Light 2" circuit breaker on STS Panel 202. During SL-4 activation the "~IDA Light 2" circuit breaker tvas closed and the Aft 2 and 4 lights were controlled by their local stvitches. ~IDA interior lights performed satisfactorily for missions SL-2, SL-3 and SL-4. 2.2.4.5 Exterior Lighting A. Design Requirements - Theaesign requirements for the ~IDA exterior lights t.ere defined in CP1l4AI000026 - ~IDA Contract End Item Specification. The basic requirements were as follows: • One set of four Gemini type running lights is to be used. (See Figure 2.2.4-13) • Provide illumination to the cretv rendezvous from 2,000 feet to 50 feet. e Sensitivity of each light must be at least 0.25 foot- candles. • Lonation and color: ~'" +Y -Y +z -z Color Green Red Amber White i, (Based on mass properties coordinate system) e Red and green light powered from one electrical bus and white and amber powered by the other AM bus. B. Functional Description - External running lights were used for gross vehicle attitude determination. They t.ere controlled and activated via the AU/DCS. Running lights were provided to allow dete."IIlination of coarse vehicle attitude alignment by the cretv during rendezvous and docking of the CS~l. The running lights tvere located radially near the unA outer skin line, but did not inter- fere with the deployment of che ATU truss as defined in 13H20726. The +Z axis (amber) light tvas partially obscured by the L-Band truss assembly. 2-237 I Figure 2.2.4-13 MDA Running Light C. Test - The MDA running light sys tem was functionally veri- fied at Denver to procedure MDA-OCP-D-60002, at St. Louis to pro- cedure D3-E72 and at KSC to procedure KS0003. All tests were com- ple ted satisfactorily . D. Mission Results - The MDA running lights performed without failure as required in support jr rendezvous and docking maneuvers . E. Conclusions and Recommendations - MDA running lights per- formance was satisfacto y. 2.2.4.6 Rate Gyro Six Pack Cabling During mission SL-2, he Rate Gyro system reflected an unstable operating condition caused by overheating of individual Rate G _ 0 ' assemblie . . A new hardware requirement was generated to bui d a contingency Rate Gyro system (Rate Gyro Six-Pack) to be incQrporated into the airborne system for use during missions SL-3 and SL-4. As a result nf this new requirement, the ~IDA Electrical group designed , fabricated , te9ted and delivered three cable sets needed to incorporate the Rate Gyro Six Pack into the MDA : • l - flight • i-DAT/flight ackup • l - Zero- g trainer A. Design Requirements - Refer to Section 2.2.4.3 A. B. Functional Description - A complete cable set consisting of: 2-238 , (1) One power and control distribution cable assembly between the Rate Gyro Six-Paclt distributor and the individual gyros (6). (2) One Y-cable assembly connecting between the control distributor of the Rate Gyro gix-Pack, the ~IDA cable connector 807W46Pl and receptacle 807W44J21 of the ATM C&D distribution panel (80~~46Pl wao launched mated with 807A44J2l). (3) One power cable assembly connecting between the Rate Gyro Six-Pack distri?utor and the ~IDA High Power Accessory Outlet No. 2 to provide 28 VDe (AM Bus 2) operating power. ~: An additional external cable was designed and built by MSFC. C. Test Requirements - Refer to Section 2.2.4.3.C. D. Mission Results - Operation of the ATM Rate Gyro system, using the Rate Gyro Six-Pack and associated cabling, met all requirements during the SL-3 and SL-4 missions and subsequent orbital storage periods. E. Conclusions and Recommendations - The Rate Gyro Six-Pack Cabling performance was satisfactory. 2.2.4.7 Rate Gyro Six Pack Meter Checkout Cables A capability to evaluate operational characteristics of each Rate Gyro was required. The operational checkout cable set consisted of two (2) cable assemblies. A. Design Requirements - Refer to Section 2.2.4.3.A. B. Functional Description - By using the two cable assemblies and a digital voltmeter, the output signals from each gyro and the internal operating temperature of each gyro could be measured I monitored, as desired. The checkout cables mated with the Rate G>~o Six-Pack Control &Lstributor and a digital voltmeter. C. Test Requirements - Refer to Section 2.2.4.3.C. D. Mission Results - During missions SL-3 and SL-4, the per- formance of the cables met all requirements. E. Conclusions and Recommendations " The Rate Gyro Six-Pack Meter Checkout Cables ped'ormance was satisfactory. 2-239 2.2.4.8 TV Hini"Honitor POI~er/Signal Cable During mission SL"3, A'.CH TV HOnitor No. 1 system failed. A requirement was generated to provide capability to use the onboard TV Hini-Honitor to replace the failed A'.CH TV Honitor No. 1 during mission S~4. A. Design Requirements" Refer to Section 2.2.4.3.A. n. Functional DeScription - The power/signal cable was a Y configured cable. The cable mAced with the ~roA Low Power Outlet lf2 (Panel No. 134),. the TV Hini"Honitor and with the A'.CH HON 1 Cable connector 80!W51P4 that mated to J-l of the ~roA Video Switch Selector Assembly. C. Test Requirements - Refer to Section 2.2.4.3.C. D. ~tlssion Results - Due to CSH storage priorities, the TV Hini"Honitor cable I~as not carried up on S~4. E. Conclusions and Recommendations - No mission data for conclusions and recommendations. 2.2.4.9 Adapter Power Cable/Hodified Lunar Drill (Electric Nibbler) A power cable was designed and fabricated to be used with a modified Lunar Drill. The assembly was to be used as a metal cutting tool in support of mission S~2. The concept I~as to use the CSH as a power source for the modified Lunar Drill during an EVA to aid in releasing the malfunctioned OOS Solar Wing Panel. A. Design Requirements" Refer to Section 2.2.4.3.A. n. Functional Description ~ The power cable configuration was a two-wire cable sheathed in convoluted scuff resistant tubing approximately 20 feet in length. One cable end terminated into a ZeroooG connector, type ZG6E2525-19PA. permitting mating to CSH Panel 230 to provide 28 VDC power. The other cab le end terminated into a IIYardney battery" drill interface connector which required a special backshell. The backshell allO\~ed for potting of the connec- tor and attachment of the convoluted tubing. The cable/connector assembly was secured to the Lunar Drill battery interface adapter plate. The cable/adapter plate then became an integral portion of the modified LUnar Drill (Electric Nibbler). Usage was to be in conjunctiOn with a CSH flyaround and a standup EVA. C. Test Requirements - Refer to Section 2.2.4.3.0. D. Mission Results ~ The modified Luna~ Drill (Electric Nibble~) and powe~ cable we~e prime candidates fo~ mission S1-2, howeve~, an alte~nate method was developed which deleted the ~equirement for the "Electric Nibble~". E. Conclusions and Recommendations ~ No mission data for conclusions and recommendations. 2.2.4.10 MDA Engineering Mockup Unit (EMU) Article A. Design Requirements - The design requirements for the finalized MDA EMU Article was to provide an MDA test article of suitable fidelity to work component, systems, crew and vehicle ~elationships. To achieve that objective, the components and cable bundles were representative in visual appearance and manual operation to thei~ flight counterparts. The specific "defined" requirements for the EMU are dp.fined in MSFC MOD, ~ffiFC-165. B. Functional Description ~ The ~A EMU electronic system consisted of nonfunctional as well as functional prototype equip- ment and circuitry. (1) Electrically Functional Equipment - The electrically functional equipment which MMC provided for the MDA EMU was as follows: • Interior Lights (8) • Entry Light Switch ~ Utility Outlet, Low Power (4) • Accessory Outlet, High Power (2) • Speaker Intercom Assemblies (3) (2) Nonelectricslly Functional Equipment ~ The nonelec- trically funotional equipment which MMC provided for the MDA EMU was as follows: • TV Outlet Unit • TV Control Unit • UV (Fire Sensor) • Inverter/Lighting Cont~ol Assembly • UV (Fire) Sensor Control Panel • 16 MM Camera Cab les • Window Heater Control Switch • Intervalometer • Radio Noise Burst Monitor (2) • Window Heater Limit Switch 2-241 'l • Bacl~up D .A.S • • Wall Heaters • Pressure Sensor PSIA • Pressure Sensor (3) Electrically Functional Circuitry H The electrically functional circuitry which MHC provided for the MDA IlliU \~as interfaced by facility power at the EHU Raclt. The electrically functional circuitry and EHU Raclt functions and their interfaces were as follows: • Interior Lights (8) 75 VAC to 117 VAC, 60 liz • 5009 28 VDC (GFP 8009) • Utility Outlets, Low Power (4) 28 VDC • Accessory Outlets, lIigh POI~er (2) 28 VDC • External Acquisition Lights (4) 28 VDC (GFP Lights) • Area Fans (2) 28 VDC (GFP Fan) , Entry Light 81dtch 28 VDC • CSH Fan (1) 28 VDC (GFP Fan) The electrical and facility interface requirements for the ~!U Reck and its interconnecting cabling were as follows: • PrOVide individual ON, OFF, and LOW brightness control for each of the eight interior lights. • PrOVide a relay to interface with the ~lDA entry light slJitch, simulating the function of the flight article's Power Distributor Assembly. • Provide intercom with subjects in vehicle. • Provide 28 VDC power to the electrically functional ~lDA equipment. • .erovide ~lDA ~ru equipment with facility power, 28 VDC and intercom. C. Test H Dur:l.ng manufacture, and upon completion of each assembly, the units were examined tlO verify .:onfo=nce to the engineering drawings with respect to materials, dimensions, con- struction, identification, and interface requirements. Acceptance tests \Jere also conducted on each assembly to assure design verification Idth intended use of the item. D. Mission Results - Prior to the launch of 8kylsb the IlliU article was converted to the One-G Training Article under a new MSFC MOD (See Section 2.2.4.11). E. Conclusions and Reconnnendations - The mru article pro- vided its required functions satisfactorily. 2.2.4.11 ~IDA One-G Training Article A. Design Requirements - The Design requirements for the ~IDA One-G Training Article ,~el'e: adequate and proper training of the astronauts and the generation of suitable crew procedures and flight problem workarounds. Compor-ent and system fidelity was required to be representative in visual appearance and manual operation. TIle specific component requirements are defined in MSFC HOD, NSFC 322 "~IDA One-G Trainer Definition". B. Functional Descl'iption - TIle ~IDA One-G Trainer electl'onic system consisted of nonfunctional as well as functional eltuipment and cll'cuitry. Due to tl'aining requil'emcnts being unique, NASA along with ~!HC support, established a fidelity matrix (Table "A" and "B" of the above l'efel'tlUced mod) to be adhered to in component and system design. (1) Electrically Functional Equipment - The electrically functional equipment '~hich ~mc provided for the ~IDA One-G Trainer ,~as as follows: • Interior Lights (8) .. Entry Light SWitch • Utility Outlet, Low Powel' (4) .. Accessol'y Outlet, lligh Power (2) • Video Switch • Television Input Stations • Extel'Ual Acquisition Lights (4) (2) Nonelectl'ically Functional Equipment - The nonelec- trically functional equipment which NHC provided fol' the ~IDA One-G Tl'ainer was as follows: • UV (Fire) Sensor (2) ., UV (Fil'e) Sensor Control Panel • S190 Window lleatel' Control Panel • S190 l'1indow lleater Cable '~ith Temp Sensol' • Radio NOise BUl'st ~IDnitor o Backup D.A.8. • Temperature Tl'ansducers (2) • Window Cover Limit Switch • 8190 Window Sensors and Electronics .. Doc\tj,ng Port lleater!l (2) " . Docking Port Thermostats (2) • Hall Heaters 40 watt (4) • Hall Heaters 20 tlntt (3) 0 : i~:~i ;~::~:~ i~::~:~:~ ~~o~ • Gas Temperature Sensor _ Cone • Auto Transformer (DI/LCA)(2) • DC-DC Converter (DI/LCA)(2) • Shorting Plugs - I/LCA(4) • Shorting Plugs - DI/LCA(4) (2) (2) (3) Inflight ~!aintenance equipment ,~hich HMC provided for the ~IDA One-G Trainer was ns follows: • Video Switch - Nonelectrically functional • Television Input Station - Nonelectrically functional • S190 l~indow Heater Cable with Temp Sensor - Nonelectrically functional • Video SWitch Contingency Power Cable - Electri- cally functional • Revis ion of ATIt C&D Conso le cab Ie interface to facilitate astronaut training toward expedient on-orbit installation of the carry up Rate Gyro Six Pack system. (4) Electrically Functional Circuitry - The electrically functional circuitry which NMC provided for the }IDA One-G Trainer ,~as interfaced with the training faci- lityat the Training Interface Panel (TIP). The electrical and facility interface requirefu~nts for the TIP and its interconnecting cabling were as follows: • TIP Functional Requirements - Provide simulation of AM Bus 1 or ~1 Bus 2 failure causing }IDA component(s) loss. Provide individual ON, OFF and La~ brightness control for each of the eight interior lights. Low brightness ,ms accomplished by a rheostat which allowed varying voltages to be applied to the lights instead of the normal 117 VAC. • Provide a relay to interface with the ~IDA entry light switch, simulating the function of the flight article's Power Distributor Assembly. • Provide power and control for the external acqui- sition lights. Provide 28 VDC power to the electrically functional ~IDA equipment. The electrically functional circuitry TIP functions and associated interfaces were as fo11ol~s: • Interior Ughts (8) - 75 VAC to 117 VAC, GO Hz • Television Input Station - 28 VDC and Speaker Inte~com Assemblies (2) - 28 VDC Signal • Rate Gyro Six-Pac!t (SL-3) - 28 VDC and Signal • S009 - 28 VDC • Utility Outlets, Low Power (4) - 28 VDC o!I Accellllory Outlets. High Power (2) - 28 VDC • External Running Lights (4) - 28 VDC • Entx'y Light Switch - 28 VDC • Rste Gyro Checkout Cables ~2) - Signal C. Test - During manufacture, and upon ~ompletion of each assembly, the units were examined to verify conformance to the engineering dral~ings with respect to materials, dimensions. con- struction, identification, and interface requirements. Acceptance tests were also conducted on each assembly to assure design verification l~ith intended lise of the item. D. ~tlssion Results - The One-G Training Article provided the high-fidelity necessary to successfully support the Skylab mission. The Article was used extensively during the mission to develop astronaut procedures and assist in developing new cables for crel~ on-orbit installation and checkout. E. Conclusions and Recommendations _ The One-G trainer successfully provided its required functions throughout all phases of the ~IDA program. 'rilis Page Intentionally Left Blank '_.i' 2.2.5 Instrumentation System The instrumentation system consisted of a signal conditional.", temperatura transducers and a pressure transducer. The temper- ature transducers \~ert' platinum resistance eleme~ts Nhich stlnsed the temperature at various locations intl'rnal and external to the ~~. The signal conditioner consisted of power supplies and bridge completion networks of which one leg was the temperature transducer. '£he measurement output range of the signal condi- tioner \~as a 0 to 20 mv signal corresponding to the temperature at the temperature transducer. '£he pressure transducer \'13S a potentiometric device \~hich measured the internal ~~ pressure. The output of the transducer was a 0 to 5 volt signal correspond- ing to ~IDA absolute pressure. 2.2.5.1 Signal Conditioner The Signal Conditioner, PIN 82000001000, provided signal conditioning for the ~IDA instrumentation system temperature measurement sensors. A. Design ReqUirements - The specific design require- ments \~ere not specified in an ICD. The Equipment Specification 82000001016, gave all the details necessary for the design. The signal and loading are described in ICD 50~U3l22. Following is a list of drawings and specifications needed for the build of the Signal Conditioner: 82000001000 82000001016 82000001018 82000001026 82000001027 Top Assembly, Signal Conditioner Equipment Specification, Signal Conditioner Assembly Test Specification • Range Cards Range Card Assembly Range Card Schematic B. FUnctional Description The Signal Conditioner provided to the AH PCH system, electrical signals proportional to the ambient temperature of platinum sensors electrically con- nected to it (See Figure 2.2.5-1). The basic Signal Conditioner circuit design came from the A~I I&C subsystem and required syn- thesis of the bridge resistors for use on the ~~. The Signal Conditioner weighed 16 pounds, \~as 475 cubic inches in volume and required 2.5 mltts at 28 VDC for operation. 2-247 TEMPERATURE TRANSDUCER REMOTE SITE RECEIVER DATA COMPRESSION f- SIGNAL CONDITIONER TRANSMITTER CENTRAL DATA REDUCTION ( LOW-LEVEL ) MUL T I PLEXER l.. AID CONVERTER USER Figure 2.2.5-1 ~IDA Temperature Neasurement System Block Diagram The Signal Conditioner consisted of 40 bridge completion cirCUits, oJ; which 37 were actively used (See Figure 2.2.5-2) and four power supplies. There \qere three unique bridge circuit designs \~hich conditioned measurements to the three requirud temperaturu ranges. The Signal Conditioner \~as divided into four groups of 10 bridge circuits and one pO\~er supply each. The four power supplies provided identical voltages (8-9 volt open'circuit) to each bridge circuit with the actual bridge vol- tage and the maximum output voltage determined by a zener diode and a voltage divider net\~ork consisting of R1, R2, R3 and the bridge itself. The bridge was designed such that the lol~est temperature to be mensured produced a null voltage condition. The null voltage adjustlnent was provided by R8. The maximum R2 Rl .0' ... ,A ,. ".,,, " ... POWER R4~ > R5.~ SUPPLY INPUT ~CRl ~Cl R3~ ,~~ 'oj .... • H R7: ~ g PLATINUM , TRANSDUCE R " ,. tJ ,,"\.RB; RT ; > ) < .~ " , . , ., BR lOGE , v ! OUTPUT + Figure 2.2.5-2 Bridge Completion Network Schematic ., nominal output voltllge corresponding to the highest temperature to be mellsured I~as 20 mv. The maximum nominal output I~as ob- tained through adjustment of R2. C. Test- (1) Qualification Test - Due to the similarity with the ATH Signal Conditioner only a delta qualification test was performed. This consisted of II shock and vibrlltion test. The primaIY rellson for this I~as the laclc of shock requirements on the ATH. The ~~ shock requirement was 380 gOB and the vibration I~as 7 g rms maximum. The operations are called out in the Equipment Specification 82000003816, Paragraphs 3.2.?,S.2.S and 3.2.2.5.2.6. A delta test was later performed to verify en- vironmental temperature requirements compliance. DI"·· .. 'g the test, 10 signals I~ere monitored I!(R AM 2 CSM AUDIO CENTER SIA MIKE AMP ALC MIKE AMP r--- -- -or; SIA SPICR AMP CCU MIKE INPUT CCU OUTPUT IMIKE AMP I I SWITCHING/ SIDETONE '----- Figure 2.2.6-3 SIA Signal Flow In this mode, private on-board intercom and voice record capability was maintained without an active ground communcation loop. The normal mode of operation required one of the channels to be configured as above, while the other channel was inter- connected to the CSM S-Band transmitter/receiver to allow real time communication with the ground. An over-view of the CSM-MDA audio subsystem configuration is shown in Figure 2.2.6-4. It should be noted that the SWS intercom was ino~erative in the normal configuration when the CSM Audio Center was off. Only in an emergency mode configura- tion was it possible to operate the SWS intercom independently from the CSM audio center. (1) Speaker Intercom Assemblies - Each SIA contained the fnllowing major components and controls: speaker, speaker amplifier, SPICR VOL control, mike, mike amplifier, COMM CHAN sw, ICOM/XMIT sw, CHANNEL B sw, and a MASTER ALARM and a Record light. The functions of the above com- ponents were, in brief, as follows: 2-269 I ____ ~. '_" __ '_"""_' __ _ , '" I '" ..., o r-------I ---- I S-BAl,D Ab"IEM:A -, I ";:1 (.~I I -I ! ,IfW!MD : L. c Rfr~l£ r: !' ______ ~L 3 I E Q u I p H ..... - .-- E N T --~ Figure 2.2.6-4 CSt.'/MDA A • udlo System ALDIC.. CO.!'L~·"'L (ALe A.) ...... ii-A , --I- I i :t!-": ,,:li.3.!1 :wOL! : Ii @ I I li. I I iA._;" __ ! (a) Sp~aker/Speaker Amplifier - The speaker responded to two input sources: a high level alarm signal direct to the speaker and a signal via the speaker amplifier for voice and Low Level Alarm. (b) SPKR VOL - Controlled the level of voice but not the Low and High Level Alarm Signals. (c) Mike/Mike Amplifier - Provided input to ALC mike amplifier for simplex mode of communica- tion. (d) COMM CHAN sw - Enabled selection of Channel A or B to the ON or SLEEP mode. In the ON mode, power was applied to speaker amplifier and the Push to Talk (PTT) relay. In the SLEEP mode, both the speaker amplifier and the PTT relay were disab led. (e) ICOM/XMIT sw - With COMM CHAN sw Channel A or B ON, the ICOM position activated the mike amplifier and, to avoid audio feedback, inhi- bited the local speaker amplifier (simplex communication). The XMIT position enabled voice transmission to ground in addition to the ICOM functions stated above. (f) CALL sw - Enabled all speaker amplifiers in the OA with the exception of local speaker amplifier and ICOM/XMIT relays (including those in SLEEP mode). At the same time, enabled the local mike amplifier and connected its output to both Channels A and B, simul- taneously. (g) RCD/OFF sw - Enabled or inhibited tape record- ing of Channel A or ~- ,nel B audio Signal (as selected by the; ::, SYS RCDR AUDIO sw on AM Panel 204). SIll. Record light was ON whenever voice recording was in progress, except when SIA was in SLEEP mode. (h) CHAN A (B) sw - Selected the operating mode of the CCU/headset connected to the Channel A (B) connector. 2-271 .. (i) r:-:iXlRD Light ,. See RCD/OFF sw function. (2) CCU Functional Characteristics - The Crewman Com- munication Umbilical (CCO) was used to connect the crewman Personal Communication Assembly (Figure 2.2.6-5) to the intercom Chsnnels A or B. The CCU, ae shown in Figure 2.2.6-6, inter- faced with a T-adapter which separated and routed the audio and biomed func~ions to the headset and the crew's bioinstrumentation assembly respectively. \ \ LIGHT WEIGHT HEADSET SOFT HAT Figure 2.2.6-5 Personal Communications A'lsembly ---------- _. --._-----_., --- .. " I i I I , I MATES WITH INTERCO!-1 ABSY CCU RECEPTACI,R ~ VIEW K-K ,M MATES WITH SPEAKER INTERCO ASSY CCU RECEPTACLE INTERCOM KEYINGPOWE PUSH TO TRANSMI R T PIN NO, r-- 15 13 26 11 26 21 53 31 22 41 39 9 3 4 55 56 45 46 5 14 6 ""-- VOLUNE CONTROL -. , .' 604, QJINS 2.5K OlillE{06v J Xl11T , ) 4 ICOM CREWMAN'S T-ADAPTER PIN HaTm; WITH NO, CRE~1.~· S T -ADAPTEI\ r-- 15 13 28 11 26 21 53 31 22 41 39 9 3 4 55 56 45 46 --- BIO-MED SIGNALS RETURN ELECTROCARDIOGRAM IMPEDANCE PNEUl10GRAPll HEART RATE BODY n;l1PERATURE CREWMAN IDENTIFICATION BIO-NED POWER BIO-MED POWER RETURN LEFT MICROFHONE POWER LEFT MlChOl'1l0NE POWER RETURN RIGRT MICROVRONE POWER RIGHT MICF.Ol'HONE POilER RETURN J EARPHONE SIGNAL 1 WARIUNG TONE S IGNAI. 1 MICROPHONE U IGNAL Figure 2,2.6-6 Crewman Communications Umbilical I ~ ! ! , I (3) LCCU Functional Characteristics - The LCCU contained audio cabling to connect the crewman Personal Commun- ication Assembly (Figure 2.2.6-5) to the Intercom channels at the SIA. The LCCU, as shown in Figure 2.2.6-7, connected to the Crewman Communication Con- trol Head AssemHy (CCCHA), Figure 2.2.6-8, which in turn mated with the Personal Communications Assembly. (ll) CCCHA Functional Characteristics - The CCCHA con- tained a volume control for the headset and a switch for intercom or PTT (transmission to ground). Two LCCUs could be connected in series if a longer umbi- lical was required. (5) Special Mounting Criteria - Shock and vibration cri- teria defined in the MDA CEI exceeded the qualification testing levels imposed on the SIA. The SIA installed at the AXMC&D console (Panel 131) was shock mounted to attenuate the levels imposed on the SIA. C. Test - As stated previously, the SIAs and associated com- munication accessory equipments were furnished to MMC as GFP. ( 1) Qualification Tests - All of these equipments, except for the headset, were qualification tested by the devp.loping contractor. However, the SIAs were sub- jected to a delta vibration qualification test because the MDA vibration and shock environmental requirements exceeded those to which the SIAs had been initially qualified. A special qualification test was performed to verify the attenuation of the SIA Isolation System. Accelero- meters were installed on the SIA which measl1red the vibration levels received at the SIA with the follow- ing levels inputted to the base of the isolation assembly. High Level Random Criteria 9.6 g rms, 1 min/axis Low Level Random Criteria - 4.8 g rms, 4 min/axis ICD 5OMl3l48 was revised to specify the increased random vibration levels for the SIA and the tests were successfully performed. , I ~ I MA.TES WITH SPEAKER INTERCOM ASSEMBLY CCU RECEPTACLE l.EFT MICROPHONE POWER RIGHT MICROPHONE POWER RIGHT MICROPHONE PO\'ER RETURN WARNING TONIl SlGNAL f EARPHONE SIGNAL [ MICROPHONE SIGNAL [ INTERCOM KEYING POWER PUSII TO TRANSMIT PIN NO ,:=... 22 39 9 55 56 3 4 45 46 5 14 6 '-- .... ------ 180" -----_-1 MA.TES WITH CREWMAN COMMUNICATION CONTROL HEAD ASSEMBI,Y PIN NO • 22 39 9 55 56 3 4 45 46 5 14 6 Figure 2.2.6-7 Lightweight Crewman Communications Umbilical 2-275 ., , .. , I 28. 7"~~ I .. :--- 21,,+1 ---.... -11 CLIP .. MATES WITH -0 (-::~ ___ -r'l-""'""1tl11LIGHTWEIGHT ~ CREWMAN --- CO~NICATION CLIP UMBILICAL MATES WITH CREWMAN1s LIGHTWEIGlrr HEADSET MATES WITH LIGHTWEIGHT CREWMAN'S COMMUNICATION UMBILICAL " INTERCOM KEYING POWER PUSH TO TRANSMrr PIN NO ~ 22 3 4 55 56 45 46 39 9 5 14 6 I-- CONTROL (ICOM) (XMIT) MATES WITH LIGHTWEIGHT HEADSET r-"4 60~ ~HMS 2.5K Ou>A~' ~ "'"1 • ---- XMIT 41CO* '. 8 13 14 1 2 10 11 6 7 "- LEFT MICROPHONE POWLP EARPHONE RIGNAL WARNING TONE SIGNAL MICROPHONE SIGNAL RIGIIT MICROPHONE POWER MICROPHONE POWER RETIlRN Figure 2.2.6-8 Crewman COlDluunications Control Head Ass"eIIlbly 2-276 (2) MDA Module Test at MMC, Denver - The MDA communica- tions system was successfully tested in accordance with Operational Checkout Procedure, OCP-D-4000l. Results of this test are included in Section 7.0 of this report. (3) AM/MDA tests at St. Louis and Cluster tests at KSC - Results of these tests are included in Section 7.0 of this report. D. Mission Results - (1) SL-l/2 - The communication system within the MDA provided the communication and data transmission capability for which it WbS designed. There were no anomalies reported by the SL-2 crew, nor were there any malfunctions reported by the ground sta- tions. However, because of the proximity of the SIAs in the MDA, feedback wouJ.d invariably occur when using the SIA microphonE' if more than one SIA was powered on. Operational discipline was required to mitigate thiS condition. Audio difficulties were reportedly experienced by the SL-2 crew while conversing directly with eacil other between SWS compartments. Crewmen in the OWS could not be readily heard by a crewman in the MDA or AM without shouting. The poor sound-carrying condition was attributed to 1:he 5 psi cabin pres- sure. Usage of the 100M mode ~n the SrAs was man- datory under these condition~. Functioning of the Caution and Warning System (C&WS) input to the SIA audio and visual alert presentation was demonstrated through the activation of a "Service Propulsion System" (SPS) Pressure Low warning trig- gered in the SWS and properly identified in the C&WS panel in the Structural Transition Section (STS). (2) SL-l/3 - The Communication system within the MDA provided the communication and data transmission capability for which it was designed. There were no anomalies reported by the SL-3 crew, other than the SIA feedback problem evident in the SL-l/2 mission which caused occasional degradation in the communicat'ions. ' Due to the close proximity of the SIAs in various sections of the SWS, audio feedback occurred and interferred with crew communications, especially with the ground. A partial resolution to the feed- back problem was made by reducing the gain of the SIA speaker amplifiers on Sky lab missions SL-l/2 and SL-l/3. This wasn't completely satisfactory, how- ever, 80 a change to the audio system was incorpor- ated into SL-4. This change conSisted of the addi- tion of an electrical load to. the microphone and earphone lines between the CSM and the MDA r.educing the overall system gain. The load on the earphone line was active only when the PTT switch was acti- vated. (3) SL-l/4 - During the SL-4 mission the feedback reduc- tion network provided a significant improvement to tl1e audio feedback problem. On DOY 333 SIA Panel 131 microphone circuit fail~d. The cause of the failure was never determined and could have been associated with any of the following electrical components: o Microphone transducer o Electronic component within microphone channel assembly o Output transformer o PTT relay o lCOM/XMITswitch contacts o Comm Channel (rotary switch) contacts The unit was remove1 and replaced. No further pro- blems were exper.ienced by any of the SIAs in the MDA. ~ E. Coaclus10ns and Recommendations - The crew reported during the SL-2 debriefing that they believed they lost some recorded voice data due to mistakenly operating the SIA ICOM/XMIT for the RECORD/OFF switch. They suggested that for future designs, the switch should be shaped differently or should operate in different directions. For future programs it is also recommended that the deSign of speaker systems include testing in a full scale mockup at flight ambients and subsequent design of thc system to prevent feedback problems. Some consideration should also be given to design of the SIA to facilitate operation from any angle in a zero-G situation. It is also recommended that portable, wireless communication assemblies be developed for use by crew members to allow more free- dom of movement and positive communication with each other and/or ground personnel. 2-278 .. --''''-1-- " , - ... , 2.2.7 ~ion andWarnins (CcSW) System The MDA CCSW subsystem was supplied to Martin Marietta as GFE for installation in the MDA. A. Design Requirements - Design requirements for the CCSW System were specified in the Cluster Requi~ements Specification, RS003M00003, AppendtK H. System and component design was per- formed by the SWS Integrating Contractor. Requirements levied on the MDI. consisted of: • A study to determine the number and location of Fire Sensor Assemblies (FSA) required to assure optimum coverage of the MDA. • Provide mechanical interface for installation of the FSAs and the Fire Sensor Control Panel (FSCP) (5OM16147). • Provide cabling iniormation to electrical design area to assure compatibility with OWS CcSW system functional requirements and the AM/MDA Electrical rCD (40M35662-2). • Provide the capability of verification and checkout of the subsystem at the MDA module level. B. Functtonal Description - The C&W system monitored the CSM, ATM, AM, and GWS for malfunction (out-of-limit) conditions categorized as caution, warning or emergency, and identified malfunctions by visual and distinctly coded audible alarms. Functionally, the caution and warning system was divided into a Caution and Warning (CcSW) subsystem and an emergency subsystem. The CCSW subsystem monitored OA systems perforn~nce parameters categorized as caution and warning conditions. The emergency subsystem monitored two hazardous conditions: fire in the MDA, AM and OWS, and a rapid decrease in pressure (rapid ~P) within the OA. Each subsystem was further divided into two subsystems, providing redundant parallel parameter monitoring and mslfunc- tiop indicators. The C&W system was active only when the SWS was manned. No ground control of the CCSW system was provided. The components used to detect and initiate a caution and warning alarm (high or low limit detection) consisted of CCSW sensors, C&Wdetector module and CCSW signal conditioning display converters. Emergency condition detection was provided by two rapid delta-P sensors located in the STS, and 22 fire sensors 2-279 -'-'--"'~-- - ,,------ installed throughout the SWS. The two Fire Sensors, one Fire Sensor Control Panel (FSOP), and the Master Alarm lights located on each Speaker Intercomrr. Assembly made up the C&W &ubsystem in the MOA. (~,ee Figures :<:.2.7-1 and 2.2.7-2.) All circuit breakers for the emergency subsystem were located on Panel 202 in the AM. Power on/off control was provided by POI"!ER EMERGENCY 1 switch (Panel 206) for subsystem 1 and POWER EMERGBNCY 2 switch (Panel 206) for subsystem 2. EPS control bus 1 supplied power to emergency subsystem 1 and EPS control bus 2 supplied power to subsystem 2. Either subsystem could be disabled and the remaining operative subsystem would provide monitoring of all emergency parame_~ers, however, all fire sensor power swItches would have to be configured to the operative SUbsystem (BUS 1 or 2). All circuit breakers and control SWitches, except for the Fire Sensor Control Switch, were in the AM STS. , ,~---------------- (1) Ultra Violet Fire Sensor Assemblies - Each UV fire sensor used + 28 vdc for internal power and provided two output signals upon sensing a flame within its coverage 20ne or application of test signal (Figure 2.2.7-3). One signal latched on the fire sensor idencification light on the fire sensor control panel, and the other drove a relay in the fire sensor control panel as long as a flame \4aS sensed. The coverage zone by each sensor was a 120-degree cone with the apex being the sensor element. An external sensitivity adjustment (requiring a'slot screwdriver) set the senso~ electronics sensitivity. Numerals 0 through 5 provided a range of 75 to 25 counts per second with position 4 (35 counts/sec) being the normal settin,;. The shielded background sensor provided protection against false alarms due to high energy particles in the South Atlantic anomaly. (2) Fire Sensor Control Panel (FSCP) - The FSCP provl.ded controls for operation and test of the fire sensor assemblies. See Figure 2.2.7-4. The FSCP had the capability of controlling both sensors in the MDA. 1\,0 power swi tches were provided, one for each sensor, which allowed manual selection-of one of two normally energized 2-280 i J N • N co ~ . ,-~~""''''''='''''~'''~=---·~~...:ruF.!I:=--F-T'_W=.E_,._.l\I!'!ll! __ .l :!t! 1lIIl_S:::::,_t.~:.~ \., ' AREA FIRE LIGHTS - f MIlA/STS FI RE ISENSOR 10 LIGHTS I A.'II AFT FIRE II PER SENSOR) AREA FI RE LI GHTS ! MDAISTS ( PNl t 120,236,237,238) • 0\'15 FWD FIRE FIRE TONE GROUP (8 SENSORS) I SENSOR I MASTER AlARM "'" OWS CREW LIGHTS ID LIGHTS QTRS ;:IRE t WARNI NG TONE • AM AFT (PNl392) GROUP f. OWS EXP FIRE (2 SENSORS) I SENSOR I '. 10 LIGHTS INDICATOR (P~JL 207&516) t (PNl 529, 5301 OViS FWD CONTROL ~I I GROUP ELECTRONICS FIRE TONE (3 SENSORS) I SENSOR I ID LIGHTS OViS CREW (PNL t 633,638, 639) (KLAXONS OViS- QTRSGROUP AM) (6 SENSORS) I SENSOR I I-H MASTER ALARM I 10 liGHTS OWS EXP .2..L2.. COMPf t (PNL 618, 619) :Ii :Ii GROUP (PNL 2CO 6161 (j SENSORS) INTERCOM BOX • I I- 1-1 MASTEll AI.ARM LT I L- f--I WARNI~!G TONE I , Figure 2.2.7-1 Fire Detection Subsystem ------- - .... ~-- ------------~- r N I N 00 N u • MOA/STS • AM AfT • O'I/S FWD • O'I/S CREW QTRS • O'I/S EXP fI~E DETECTION GROUP SENSOR 10 LIGHT 122/ ON RESPECTIVE FIRE SENSOR CONTROL PANEL • MOAJSTS • AMAfT INHIBIT • OWSfWD SW PNl1!l7 • O'I/S CREW QTRS , flJlE? • O'I/S EXP • flqE2 TEST (PNl206) • MDA I STS INHIBIT sw • MIAfT fiRE I • OWSFWD • O'I/S CREW QIRS • OWSEXP • FIRE I l5T PULSER (PNl206) (EMER SUBUNIT II (PNl 206 & 616) o-r SENSOR IJ~I :;~ ~ lOF12 FIRE SENSOR @: CONTROl. PANELS TEST INDICATOR CONTROL !C&w SUBUNIT 2 EMER SUBUNIT 2! Figure 2.2.7-2 Fire Detection Functional .- • • AREA FIRE UGHT • OWS fIlID fiRE • OWSEXPFlRE • OWS CREW Q1RS fiRE l~l1!l7 U!6l FIRE TONE -ONE OUTPUT I'D! FIRE OETEC1ION GROUP FIRE SENSOR CONTROL PANEL UV FIRE SENSOR 10 TO 33VOC DETECTOR ElECTRONICS BUS 1 • :: +15 VDC Of Fe ,NPUT 13 DCIDC -15 VDC .~ CONVERTEr! ~ +5 VDe BUS 2 • - 350 VDC I - EXT SENSITIVITV FIRE COVERAGE r------, \" ( ~"""' '"J2f 10,1,2,3,4,5) I TO I :;:t COMPARATOR r"'f'1 ISHIELDED f I F.MI::R I 1 SUBUWT 1 1 ~ , r- -- ----t , OUTP~T SIGNAL "1~:CKGROUNDI I I TO I , ~ +l2V: FIRE r-- SUMMING 5 NSOR I EMER I -12V - NO II I L_~B~~T!_J , FIRE NETWORK...-J UV 120 I FIRE 1 '",. N SENSOR I ,LATCHING . '35"L~ \ RELAV ~~ "::" I LAMPORI~ 1REO _____ l.r.\ II nil I, II : '-../ r-------·---, \..J.,.- I' ~ Ii uv SENSOR 1 MASTER MASTER ALARM I TEST ALARM I RESET FUNCTION: SOURCE RESET ::1'. LT£~~V ______ I e-!----- ( I TEST • Figure 2.2.7-3 UV Fire Sensor £~--~ , \ J t:'lo r©f~ ,... ,... ,... 0 0 @ SENsor.t S~NS(.'R 1 2 MASTEFl At..ARM RESET BUS I 00" U @~a ~ 0 ~. Ir~' ~ F ·F ~1 e~:;;'( @ U BUS~ TeST '"" '-' @ Fire Sensor Control Panel (FSCP) Figure 2.2.7-4 Fire Sensor Control Panel 2-283 --- " I buses capable of supplying power to the respective sensor. A master alarm reset/test switch was pro- vided for testing the sensor(s) and resetting the SWS C&W system. A red display lamp was provided for each of the two sensors and remained illuminated until power was momentarily removed from the senl'toJ:. Each display contained one bulb which drew 40 milliamperes of current when illuminated. The bulbs and lenses on the panels and the panels themselves were in-flight replaceable. When both sensors were energized, the panel dissipated 5.5 watts of power. The FSCP l'leighed 1.4 pounds. (3) Fire Sensor Test - Individual fire sensor testing was accomplished by the MASTER ALARM RESET/TEST switch on the respective remote fire sensor control panels (Figure 2.2.7-5). Actuation of the MASTER ALARM RESET/TEST switch to TEST applied a test signal to an UV test source in sensors 1 and 2. Individual fire sensor testing was accomplished by turning power off to either sensor 1 or 2 as desired' prior to performing the test. MASTER ALARM reset and cycling of ~he sensor power switch to off and back to the bus 1 or 2 position was required after each sensor test. LAMP LATCHING CICl @ I. EMf. SUBUNIT 1&2 Figure 2.2.7-5 Fire Sensor Test 8206 @ " 'r I I I , I I (4) Performance and Design Data - UV Fire Sensor Aseembly • Input Voltage • Input Power • UV Spectrum Sensitivity • Response to Test • Size • Weight 18 to-33 vdc 3.6 watts standby, 6 watts active 1850 to 2650R Approximately 1 sec 5.3 x 5 x 3.15 inch 5.8 pounds For a more complete description of the Sky lab Caution and Warning System, see MSFC 40M3570l, Skylab Caution and Warning Technical Manual. C. Test - The FSCP and FSA were provided to MMC-Denver as GFE to be installed in the MDA. Subsystem testing waB accom- p~.shed on-board the MDA per MDA-OCP-D-10001. An ultraviolet light test tool was designed and functionally tested per SK82ODM6020 OP125. Two fire sensors failed subsystem testing. The units indi- cated the presence of a fire during a background noise verifica- tion test. The units were bench tested and all hardware functioned per specification. The test requirement and procedure were sub- sequently rewritten. The MDA C&W subsystem was satisfactorily tested in St. Louis and at KSC per STACR ED-2002-2020. There were no other failures in the C&W subsystem during Denver Testing. D. Mission Results - C&W hardw&re components in the MDA functioned satisfactorily throughout the Sky lab mission. E. Conclusions and Recommendations - The Caution and Warning system performed its intended function adequately. However, it is recommended that future designs provide sufficient isolation to prevent intra-system noise from inadvertantly coupling into other systems. For example, the converter switching spikes asso- Ciated with the emergency power 8latem caused data perturbations on MDA Temperature measurements. MOdifications were incorporated but the problem was never totally eliminated. ,·1 __ - This Page Intentionally Left Blank 2-286 TV 2.2.8 Television (TV) System Major TV system components installed in the MDA included a Video Switch, Television Input Station (TVIS) and a Video Tape Recorder (VTR). (Ref. Figure 2.2.8-1). A discussion of each of these components, including their contribution to the performance of the OA TV System, is included in the follOWing paragraphs. ATM MDA CSM ATM ATM OWS Video Video 1 2 5OM16131 5OM16159 5OM16149 Video Video CSM I..- Selector ~ Tape Switch r- Trans- Switch Recorder miller TV TV Input ~ Input. I- Input 15OM16149 Station Station Station ~ ...... TXput AM TV m Input ~-iiJ-' 5OM16154 Station Station .9~r:!)~i ...... I '" l W Monitor Power r, TV ~ I I L_J - Camera 5OM13l22 5OM13125 Monitor Figure 2.2.8-1 Skylab TV System 2.2.8.L Video Switch A. Design Requirements - The design requirements for the Video Switch were specified in Drawing PD7l00078. The system re- quirements applicable to the Video Switch were specified in the fo llowing lCD's: 50M16l32 - Sky1ab Orbital Assembly Television Systew Requirements 50M16139 - Multiple Docking Adapter Measurement List 50M16131 - ATM to AM I&C Interface 50M13122 - AM to MDA I&C Interface 5OM13125 - CSM to MDA I&C Interface 2-287 .. B. Functional Description - The Video Switch, Figure 2.2 .8-2, provided manual switchinfl and conditioning of TV video signals (rom the ATM or the MDA/AM/OWS TV bus. Figure 2.2.8-2 Video SWilCh The switch was a three-position rotary switch with posilions for A1M NON 1, ATN NON 2, and TV. The switch was hardwi.ed to two 75 ohm coax cables from the Al'1/AT!-I interface "nd one 93 ohm cable from the !-IDA TVIS. Another 93 ohm coax connected the video switch out- put to the VTR and through the V1R t.:> the CSN unified "s" band transmitter . Power (28 VDC) was supplied from the Airlock Circuit Breaker Panel 202. The unit h"d no local power switch. The unit conditioned the video signals as follows: ATN imped~nce of 75 ohms was converted to 93 ohms and the ATI! video signal bias and ampli- tude were adjusted so as to be compatible with the S-band trans- mitter . The portable TV camera bus signal was not conditioned . 2-288 I The AIM signals were isolated from each other, each having a separate power supply and conditioning circuitry. Adjustments were provided for both gain and bins. The ATM TV camera video for each of the two channels was se- lected at the ATM C&D panel from one of five TV cameras in the ATM. The video being viewed on the ATM C&D TV monitor ill could be routed to the VTR and/or transmitter by placing the video switch in the ATM MON #1 position. Likewise, selection of ATM MON il2 permitted that video being viewed on ATM C&D TV monitor il2 to be routed to the VTR and/or transmitter. In the TV position a relay was activated whtch connected the output of the TV bus through the video switch to the VTR and trans- mitter. When in either ATM position, the TV hus coax was connected to a 93 ohm load internal to the video SWitch, with the shield heing connected to structure. This provided a fault current path in the event of a short in the portable camera. The Video SWitch had three event measurements which indicated swit~h pOSition to the ground controller via the AM telemetry sys- tem. These were 28 V indications to the TM system and w~re dis- played on the ground console as ATM MON 1, MON 2 and TV. C. Test - The test requirements for the Video SWitch were specified in the PD7100078 drawing. Bendix Corporation Report No. 5426A covered the qualification testing. There were no anom- alies reported in the follOWing tests: • EMI: MIL-I-6181 and CEOI, eso,; of MIL-S'rD-461 • Thermal Vacuum: Temperature Pressure - +400F to 900F; - 321 mm Hg to 5 mm Hg • Vibration: 7.4 grms for 1 min/axis; 3.7 grms for 2 min/axis • Shock: 60 gs - 6 shocks/axis • CCOH: I percent salt solution followed by oxygen and humidity • Temperature, Altitude, andfStorage: Temperature _400 F to +l60oF; Pressure, Sea level to 35 K ft Because of the addition of the TV bus relay which provided a ground connection for the shield, a Delta Qualification Test was 2-2.89 •. I . --------- performed which consisted of Acceptance Tests and Delta Qualifl.- cation Vibration. There were no failures reported. The results of these tests are covered in Bend ix Corporation Report M'['-17, 701, dated October 1972. The system testing at Denver Dlld St. Louis was minimal. The unit received comprehensive system test at I!Hz .., '" 5. 6. Radiated interference at 436 MHz Narrow band method RE02 at 880 MHz Radiated susceptibility ~lethod R503 Exceeded level from 59 MHz to 62 MHz NOTE: TVIS is ON ~nly when camera is plugged in and TV system curned ON. SPEC LIMIT 90 db 90 db 90 db I>!EASURED 14!l db 140 db 119 db 70 db out of 66 db out of 40 db out of 11 db above limit 13 db above limit REl1ARKS Violation only occurs when power switch is actuated spec Violation only occurs when power switch is spec actuated. spec spec The emission was found to be common mode spec 123 KHz and peaks of 2 mao 25 db above spec Violation only occurs limit when power swit~h i3 actuated. 18 db out of spec 7 db out of spec 1.0 Volt/Meter Reduced RF level to .25 Volt/meter or 12 db be 101. required level to pass. Table 2.2.8-2 TVIS EMI Deviation Report , L " i !, , ~, I " I: l' r , r , , f f , I I I , (3) Delta Qualification - Report #3512 - Due to a re- vision in thp. vibration requi.rementR, D delta test was performed. While the overall composite level was lower (27.7 grms), there waR much more energy concentrated at the lower frequencies. This was the main reason for the performance of the test. The test Was successfully completed using SIN 7 TVIS with no nnomDlies. (4) Acceptance Test - The purpose of the acceptance test was to prove out the assembly of the produc- tion units. The test consisted of a thermal cycle test and a vibration test at 7 grms/axis. A func- tional test was also run before and after each en- vironment. The results of the ATP tests were suc- cessful. The major anomalies consisted of the following: (5) • ST88D8 EMI filters had a shorted capacitor. The problem was traced to foreign matter in- side the filter. All filters were returned to the vendor for additional tests to update the part to "hi-reV' status. All filters in the TVIS were replaced. • The bottom shell of the ST82D29 connector (Jl and J2) became loose. This was corrected by the addition of a small amount of "Locktite" to the threads as well as torquing the bottom shell to 8 to 10 in.-lb. The above changes were incorporated into the draw- ings. The functional tests and the final check- out of the 1VIS consisted of the following: Impedance Isolation Gain and Bias Frequency Response Insertion Loss Power System Test - The system test program took place at Denver, St. Louis, and KSC. At Denver, all tests were completed successfully with the exception of an isolation test. This test showed a short between the +28 VDC power return ~nd 2-297 structure. The problem was traced to a shorted EMT filter (see C. (4), herein). As noted, all EMI fil- ters were retested And replaced. At St. Louis no anomalies occurred. However, during a system development test excessive reflections ,~ere noted. The problem WilS traced to the impedance mis- match caused by the 10 ohm output impedance of the TVIS nnd the impedance characteristics of the RG 180 coax at these relatively low frequencies. All TVIS' s were returned to Denver and the output impedance rnised to 93 ohms. During subsequent system testing at St. Louis, no further anomalies were reported. At KSC, a series of anomalies occurred. One was a reported gain change. The output of SIN 11 was re- ported to h:Jve be~n ""t to 3.72 VP-P. After a period of time it dropped to 3.24 VP-P. Subsequent burn-in testing, thermal cycling and vibration t"st- ing with 100 percent monitoring could not verify the failure. The unit was sent to St. Louis as the in- flight maintenance unit for the backup article. The next anomaly was reported against SIN 16. This unit was located in the OWS which was tested for the first time at KSC. The offset voltage was reported to be high and out of specification. In testing and investigation at Denver it was discovered that a selected value resistor was chosen incorrectly. Re- selection of the resistor corrected the problem and retest resulted in no further anomalies. All other TVIS records were checked to verify correct resis- tor values. The next problem that occurred nt KSC was mechani- cal. It WilS discovered that the portable camera cable did not mate with SIN 13 TVIS. The problem was traced to a tolerance build-up of the camera cab1.~~ connector. However, the solution was to tight',,, :1? tolerances allowed on the TVIS side and use shit""' ,,,der the Airlock adapter where neces- sary. This approach was chosen because it was the quicker solution and would not require retest. No further anomalies occurred during the rest of the system testing at KSC (6) Backup System Testing - As a result of the flight system and development testing programs no signifi- cant problems occurred during the TV testing that could be attributed'to the TVIS. Backup system 2-298 I ~ " i ----- testing was the same as that performed on the flight vehi.cle. All anomalies encountered during the entire testing phase were lnalyzed and proper design adjustments were made. These changes were all incorporated in- to the qua,ification and prodUction units. (7) Special Testing (a) Relay Moisture Test - An alert against Tele- dyne RF relays was concerned with inoperative con- ditions,due to moisture internal to the relay. At the time a requirement was made to test all relays (CCBD800-70-0859) prior to installation, only two TVIS units were left to build. As a result, o~ly two relays were tested. The test consisted of energizing the relay at 140 percent of rated coil operating voltage for a period of two and one half minutes. An electrical check of the relay was per- formed before and after the stress test. The primary characteristic observ~d was the insulation resistance. A change in the resistance before, during, and after the test would show the presence of mllisture. In the test no change was noted and the relays were installed in SiN's 17 and 18. (b) Gain vs Turns - Due to the interchangeability of the TVIS units it was decided to run tests to determine the gain adjustment when moving the unit from one position to another in case of a failure. The results were first found analytically using specified cable losses. The analytical results showed the adjustments were needed. However, tests both at Denver and at St. Louis showed that the total adjustment was less than 3/4 of a turn. This was felt to be so nominal an adjustment that it would not be needed if it became necessary to perform a change-01.,t. During SL-4 this was proved to be true when the spare was used as a replacement for the TVIS in the OWS. No adjustment was made and the video received was satisfactory. D. MiSSion Results (1) SL-1/2 - No anomalies occurred during the first 'Sky1ab mission which could be attributed to the 2-299 , I -~- TVIS. All units, with the exception of the AM TVIS, were used during real time 1V transmission. The units in the OW5 were subjected to higher wall temperatures as a result of a meteoroid shield loss during launch. However they still operated proper- ly with no observable problems. Flight performance was analyzed by viewing flight video data. Nominal performance by all units was indicated. '(2) 5L-3 - During this mission all units were used. The AM unit was used during the EVA of DOY 236. During this EVA the camera failed due to over- heating. To verify that it did not cause a prob- lem with the TVIS, the AM unit was used at a later date. No problem Was observed. (3) SL-4 - During the mission all units were again used. On DOY 361 the crew reported a broken pin in the Airlock/Microdot connector on the TVI5 located in the OWS. At the crew debriefing it was stated that the pin had been broken while attempting to straighten it. No explanation of how the pin was bent vas given. The unit was replaced and the mission was completed with no further anomalies. E. Conclusions and Recommendations - The prime areas of im- provement for the TVIS would he: • Increase in the gain-bandwidth product • Use of a potentiometer for bias adjustment • Use of smaller connecto.s for Jl and J2. (1) The need for the increase in gain-bandwidth became evident when the output impedance was raised to 90 ohms. The original design had a 10 ohm output impedance. Analysis had shown that there would be little reflection due to the mismatch. Howeve1, actual system tests showed that reflections were greater than expected. To reduce tbe reflection, the output impedance was raised to 93 ohms. As are- s~lt, the gain needed to maintain the required out- put was increased. The efiect of this was more roll- off from 2 MHz to 4 MHz. The exact roll-off is shown in Report ED-2002-l550. For future usages, thought should be given to improving this design. 2-300 I i " I I I 2.2.8.3 (2) A potentiometer could have been used for the bias adjustment. Possible movement during vibration was the main reason for not using it. However, the use of a gain potentiometer provided an ext'mp 1e of satisfactory stability of a cermet potentiometer. If the bias potentiometer had been used, time would have be~n saved when the R7 (bias select) was re- placed as a result of specification change. (3) In the design of ~he TVIS a new coax connector was developed which plovided isolation of both center pin and shield from chassis ground. The conn~ctor worked well, however, it was very bu~ky for a unit of the TVIS's size. A TNC bulkhead mounted on fiberboard would have been adequate and would have reduced the overall envelope. Video Tape Recorder (See Figure 2.2.8-4) A. Design Requirem~nt - The Video Tape Recorder (VTR) was a modified version of the RCA ERTS VTR originally built for Goddard Space Flight Center. The Interface Control Documents which describe the VTR are: ICD 50M16l59 ICD 50MlP132 Video Tape Recorder and Audio Splitter to Multiple Docking Adapter Interface Sky1ab Orbital Assembly Television System Requirements B. Functional Description - The Video Tape Recorder con- sisted of a tape Transport Unit (TU) and an Electronics Unit (EU), each in its own separate package. Thc TU was installed in a 21.5" X 15" X 6.5" hermetically sealed housing. The EU was psck- aged in a 16.75" X 16" X 7" housing. These two units were con- nected together via four cables and had a combined weight of ap- proximately 74 pounds exclusive of interconnecting cables. The transport contained 2,000 feet of special two-inch-wide video re- cording tape which was scanned transversely by a rotating head with a head to tape speed of 1,964 inches per. second. The ta~e was re- corded or played at a tape.speed of 12 inches/second resulting in a 30-minute minimum record time. The rewind speed was four times faster. The wide-band recording electronics were function- ally similar to those used in cqnventional broadcast television recorders. The recorder had a bandwidth of 4 MHz. All circuitry was designed to insure an operating life per- formance of three years. 2-301 Figure 2.2 .J-4 Video Tape Recorder The recorder electronics included circuitry for control and telemetry. The VTR could be controlled manually or by ground co~ mand with the exception of playback, which coutd only be controlled by ground command. The command system had beel designed such that command sequencing was performed internal to che recorder, thus de- leting prerequisite commands from most VTR operating modes. The following functions could be commanded from the ground: • Headwheel Drive Motor On, • Headwheel Drive Motor Off, • Fast Forward, • Rewind, • Playback, • Record. The VTR provided an output signal to the MDA for telemetry transmission of tape position. This signal was a 0 to 5 volt signal in which five volts indicated no tape had been used, and zero volts indicated that all tape had been used. The VTR was connected to a Speaker Intercom Assembly (SIA) in the Sky lab audio system. The VTR accepted a voice signal from 2-302 the earphone circuit and interleaved it with the recorded video such that a single composite signal was available for transmission to the STDN. In the event that one or more external VTR command lines became disabled, a separate device called the Command Transfer Unit (CTU) could be used to sacrifice less important commands and restore necessary ones. The CTU was essentially an in~line patchboard whi.ch permitted cross-patching of command functions. C. Test - A nonflight VTR was installed in the MDA at St. Louis. During icolation testing the 28 vdc return line was found to be only 10 ohms above structure ground instead of the re- quired isolation. 'rbe VTR was returned to the manufacturer for rework. After rework the unit was reinstalled into the MDA at St. Louis and tested briefly. During this test, data was recorded q,d played back through a CSM simulator and transmitted to an S- Band STDN receiver. This nonflight unit was then returned to RCA. The flight VTR was installed in the MDA at KSC. Isolation tests determined that an audio cable shield was grounded. This was traced to a VTR connector pin which was grounded internal to the VTR. Although thi. ground was in conflict with the control- ling lCD, the module cable shield termination was changed in the intereBt of speed and simplicity. Subsequent testing revealed that the·tapearemaining·telemetry channel calibration was incorrect. A problem also developed be- tween the VTR and the audio spUtter. The audio splitter was GSE equipment whose purpose was to r.~cover tlle audio recorded on the VTR. The bias in tlLe VTR wall not compatible with the audio split- ter and the voice recordings we:ce not btelligible. As a result, the VTR was returned to RCA for rework. During retest, streaks were occasionally seen across the mon- itor. The problem was traced to the interleaved audio. However, since it was only observed when the audio levels were high and the monitor was set up for high contrast, it was judged acceptable. No further anomalies occurred during testing. D. Mission Results - VTR (1) Skylab 1/2 - The VTR operated properly throughout the S1.-l/2 mission. All uplink cOlDIIIBnds were suc- cessfully exercised except the RECORD function. The RECORD function was always operated by the crew. Since all commands operated satisfactorily it was not necessary to utilize the CTU during S1.-1/2. 2-303 (2) Skylab 1/3 - The VTR operated properly until mission day 6, when it failed during a playback. On-board troubleshooting, using ground-formulated procedures, isolated the probable cause to the EU. The crew replaced the flight VTR with the inflight maintenance unit and restored video record1.,'~ capability. It was thought that the TU may have b,·".n damaged, either by the BU failure o~ the fact thut it had been left ON for approximately 13 hours. Skylab Test Unit (STN)/ STDN testi~~ revealed that only the failed EU need be replaced.on the next mission (S1-4). The EU from the backup MDA VTR was being prepared for launch on S1-4 when a loose connector was discovered on the unit. It was found that the connector nut had not been epoxied in place. The connector was tightened and epoxied, and the unit was shipped to KSC for launch on S1-4. Failure mode analysis on the ground led to the deci- sion to have the crew remove four printed circuit boards from the failed VTR EU. This was done accord- ing to a procedure developed on the ground. Upon return of the four printed circuit boards to the manufacturer, failure analysis isolated the failure to an inductor on the Video Demodulator board. The failed inductor was replaced and all four cards were inspected, X-rayed, temperature-cycled and tested. These four boards were launched on S1-4 for replace- ment in the failed VTR BU. The inflight maintenanc~ VTR operated properly throughout the S1-1/3 mission after its installa- tion on mission day 6. The CTU was not used during S1-1/3. (3) Sky lab 1/4 - The VTR operated properly during the entire S1-1/4 mission. The four p.e. boards carried in the C5M by the crew were not used. The unit installed on mission day 6 of 51-1/3 operated suc- cessfully and so there never was a need to repair the unit which failed. No problema were indicated with the uplink commands. As a result the CTU was not used during SL-4. 2-304 I 1 I I f I ) E. Conclusions and Recommendations - The flight VTRs ade- quately performed the required functions throughout the manned Skylab missions. However, the following recommendations would enhance the capability and usability of the VTR. (1) Remote switching would allow a crew member to start and stop the recQrder without going to the VTR loca- tion in the MDA. (2) A visual readout of tape pcsition, which could be read by a crew member, would aid in tape management. 2-305 ~-··-'-i --------- '-"' •. 1 This Page Intentionally Left Blank 2-306 I -.. -- J 2.2.9 Cr~ Systems 2.2.9.1 Cr~ Stations A. De.ign Requirements - The design requirements for the MDA Crew Stations were delineated in the Cluster Requirements Specifl~ cation (CRS) RS003M00003. The following is the Cr~ seGtion from the CRS, Appendix G: Cr~ Stations - The cr~ stations established for accomplish- ment of mfS8ron activity are generally located as shown in Figure G-l (figure not included herein). Multiple Dockins Adapter (MDA) . a. In addition to those requirements specified in paragraph 3.1;1.1.4.2.2 of the basic Cluster Requi7~ents Specifica- tion, the following items shall be prOVi"J in the MDAr, 1) Lighting and associated controls. 2) Caution and Warning 5y.tem (audio only). 3) Communication stations. 4) Ventilation fans. 5) Astronaut mobility/stability aids. 6) Utility outlets (high and low power). 7) Experiment and vi~ing windows. Also applicable were Sections 3.1.1.1.4.2.2 Multiple Docking Adapter (MDA) which specified the basic requirements for eluster integration of the MDA, and 3.1.3.7 which referenced MSFC-STD-267, lOM32447, and MIL-STD-1472 as guides for .tandard. and practice. for human engineering design for n~ harduare and Appendix G, Crew System Design Requirements, Section 2.1 System Requirements. B. ~unctional Description - This section described the crew stations of the MDA. The MDA had crew work stat.iolls at the ATM C&D console, EREP C&D panel, EREP Vi~finder Tracking System (VTS) , and the M512/479 Material Processing in Space Facility (MPF). B~cause of its small volume, the MDA module was also treated as a cr~ station in the evaluation. This crew station section will discuss work space, work space layout, reach envelope., habitability factors, and compatibility between cr~ station •• ----- -----~ The term crew station was rather a generalized term. Originally it was associated with control panels and experiment installations but as the MDA r~ceived additional installations such as the EREP experiment, the VTR and numer~us stowage containers, the whole of the MDA was looked on as a crew station by the flight crew. With the growth of the MDA installed experiments, it became obvious that task and volume sharing was required and this requirement became part of the crew station definition. The primary criteria for defining a crew station was the provisioning required for long dura- tion, two-handed tasks. Where these requirements were identified a foot restraint was provided; i.e., EREP COD Panel, ATM C&D console, and the MS12/479 facility. The single exception was the VTS crew station for EREP. The foot restraint for this station was deleted at the astronauts' request. The rationale for the VTS was that hand- holds mounted on the VTS panel would adequately position the operator and give hill the freedom to quickly move away from the station and back again. The crew believed this would be easier to do if they did not have to disengage their feet from the foot restra~nt grid. Each crew station was evaluated by task analysis to establish the operator's functions. His reach and work envelopes were major constraints for positioning the foot restraint at the crew station. Tradeoffe and compromises were made as required and on occasion, equipment was re-positioned, e.g., the positioning of SIAs at EREP, MS12/479 and. ATM C&D console. Where operator volume sharing was required, the scheduling of the experiments was studied t~ assure no conflict existed such as between EREP VTS and the MS12 which share the same work envelope. (1) ATM C&D Crew Station (Ref. Figs. 2.2.9-1 and 2.2.9-2) - The ATM Crew Station hardware consisted of the C&D Panel, the ATM foot restraint, the chair and a speaker intercomm assembly. The ATM COD console was originally designed for seated operatiqn and installation in the Lunar Module (LM). Although changes were made in the panel for Skylab, its basic siz~ and shape did not change. At crew reviews early in the program, the astronauts elected to operate the ATM COD Panel from a standing position. This decision was based on two considera- tions, 1) that two operators may be required at the ATM, and 2) the requirement to monitor the STS con- trol panel while physically oriented at the ATM C&D Panel. Neither of these requirements remained by the time the Sky lab was being readied at KSC and the 2-308 I I' I . ' .. Figure 2.2.9-1 - Crewman at AIM Crew Station (left view) Figure 2.2.9-2 - Crewman at ATII Crew Station (right view) 2- 309 decision was made by the flight crew commander (CDR) to install a chair at the ATM COD console. To pro- vide flexibility in the chair, its seat and back angles could be changed and its height adjusted. It was mounted with captive connectors in the ATM foot restraint grid and stowed in the Orbital Work- shop (awS) for launch. The ATH COD foot restraint was composed of the Skylab triangular grid; j.t was the same length as the con- sole width and approximately 20 inches wide. The foot restraint was adjustable in 3 positions, at 6-in. increments, vertically to the panel face. (2) EREP COD Crew Station (Ref. Fig. 2.2.9-3) - The EREP crew station hardware consisted of the COD Panel, the S 190 camera array. the S 190 stowage container, a speaker intercomm assembly, and the MS12/497/EREP foot restraint. The major crew interface with MDA hardware was with the foot restraint. The original foot restraint concept for the EREP COD console ,~as a grid platform, serving both the ERE~ COD Panel and the VTS. Functions on the COD Panel were not fully developed and were quite limited at that time so it was decided to remove the COD Panel foot restraint but leave the VTS foot restraint. However, during this design period a crew review reversed this concept placing the foot restraint back at the COD Panel and removing it from the VTS. It was at this crew review that the recommendation wa.s made to use a combined MS12/479 and EREP COD Panel restraint. This is the concept that was ulti- mately designed and flown. The EREP COD Panel foot restraint fitted into mount- ing brackets and provided a standing orientation of the operator to the panel with the center of the panel chest high to a 50th percentile astronaut. This restraint was not adjustable in its vertical orientation to the panel. It was removable for pOSitioning and utilization at the MS12/479 experi- ment. 2-310 F I ~~Il r. ' 9 - \ • Cr, '\-'I1I, 111 . 11 Eln:p C~J) Cr, '\v S( , II i ~ lll 2-311 ... (3) EREP VTS Crew Station (Ref. Figs. 2.2.9-4 and 2.2.9-5)- The VTS crew station hardware consisted of the View- finder/Tracking System, its associated control and display panel and a clipboard restrained on the S19l closeout cable cover. A crewman al: this station utilized the SIA located adjacent to the MPF. No foot restraint was provided at the VTS crew sta- tion. Handholds on the VTS panel were pr~vided for crew positioning and operation at. this station. The operator needed to interface with the EREP SIA and the C&D Panel. Neither of these units were posi- tioned to provide this capability from a foot restraint. (A major modification to the MDA equip- ment arrangement would have been required to con- figllre this station for that capr,bility. A modifi- cation of this magnitude was deemed undesirable at that time.) (4) MS12/479 Material Processing Facility Crew Station (Ref. Fig. 2.2.9-6) - The design of the MS12/479 crew station foot restraint utilized the same restraint platform provided at the EREP C&D console, but repositioned to the MS12/479 experiment. The placement of the restraint in the MDA provided the operator with access to all the pallet-mounted MS12/479 equipment, the MS12/479 SIA and the two 4-inch vent valve handle~ controlling the experi- ment furnace venting. Du,~ to the wall mounting of the MS12/479 and the positioning of the mounting pallet, it was not possibla to position the operator to the MS12/479 in a standup position. The resul- tant operator position was a compromise between a standup attitude and a positi.Oll wherein the operator leaned slightly forward to operate the experim~ ItS. In effect he assumed a bent-over "hovering" position. This presentation to the exp.,riments was evaluated in the Neutral Buoyancy Facility (NBF) and deter- mined to be satisfactory. 2-312 I I Figure 2.2.9-4 - Skviab Crewmen at EREP VTS and C&D Crew Station Figure 2.2.9-5 - CrcwmJn 3 t VT5 Cre" Station 2-313 Figure 2.2.9-6 - MS12/479 Experiment Crew Station (5) HDA Module Work Space (Ref. Fig. 2.2.9-7) - The significant feature of the HDA as a crew work area was its cylindrical layout of hardware and crew stations as opposed to the OWS floor-ceiling arrangement of equipment and crew work stations. The evolution of the HDA from a five port docking adapter to the two-port docking adapter and experi- ments/stowage module resulted in an add-on approach to interior layout. This prevented a dedicated area approach to HDA layout of experiments and stowage. Experiment work stations were laid out according to space available rather than with a specific orientation in mind. 2-314 , ) . , I -- Figure 2.2.9-7 - Total HDA Workspace The crew interfaced with the HDA in the following areas: • Passage between the AM and the CSM. • Stowage of hardware and support "equipment for experiments. • Performance of experiments at the respec- tive crew stations. • Stowage of probe and drogue during activa- tion. • Photography and TV recording of IVA activities. C. Test - Crew station reviews wer~ held at Denver, St. Louis, and KSC as discussed below: 2-315 (3)' _ 'fl • 18 Discrllpancies dispositioned rework to engineering • 30 Discrepancies agp{nst &TP/Experiment hardware • 13 Discrepancies requiring flight crew nomenclature changes • 21 Discrepancies requiring hardware changes. The most significant hardware changes involved captivating screws, addition/modification of Velcro, stowage relocation of an S056 magazine to reduce interference and the extension of inflight stowage straps to ease operational access. The intent of this test was to have a total with items n~t accomplished in Denver to be in delta C2F tests at St. Louis and KSC. During the course of this test, the flight crew also made a subjective evaluation of the MDA lighting with the result that it was considered low but adequate. 2 2 St. Louis Crew Compartment Fit and Functional (C F ) Test - The St. Louis C2F2 test was a composite of four events utilizing a common test procedure, MDA- OCP-S-8000l. The first two events were incremently held in February 1972 utilizing the vehicle in a vertical orientation. The third event '~as a bench review held in May 1972 with the final event a com- bined AM/MDA C2F2 held in June 1972 with the AM/MDA horizonta 1. The culmination of all crew tests held at St. Louis resutted in 40 discrepancies. Trie breakdown of these discrepancies follows: • 20 Discrepancies against GFP/experiment hardware • 3 Discrepancies dhpositioned no item • 4 Discrepancies dispositioned rework to engineering • 6 Discrepancies requiring flight crew nomenclature changes • 7 Discrepancies requiring hardware changes. 2-316 (4) The most significant hardware changes involved captivating washers to bolts designed for in-flight removal ~hanging the mounting hardware for the lV input station and video switch, adding a 1/16 Allen wrench to the MDA tool kit and adding additional restraints to the miscellaneous stowage container. KSC Crew Compart~nt Fit and Functional (C~2) Test - The KSC C F2 was held in April 1973 for the MDA portion of the SL-l. The test was conducted U~i~izlng the MDA portion of KSC-OOIO Integrated C F Test. Prior to the test, all available flight crew and experiment equipment available at KSC was launch stowed in accordance with MDA stowage pro- cedures KM-3014 and KM-7000. At the conclusion of the test, 13 discrepancies were recorded. Their ~reakdawn follows: • 7 Discrepancies against GFP/experiment hardware • 2 Discrepancies dispositioned no item • 1 Discrepancy re.quiring flight crew nomenclature changes • 3 Discrepancies requiring hardware changes. The three hardware changes consisted of removing the blue paint from the ATM handrail due to chipping, stowage configuration changes for EREP attenuators and the MDA tool kit launch pip pins. D. Mission Results - (1) ATM C&D Crew Station - The comments made by the SL-2 crew on the ATM C&D crew station were generally favorable except for the layout of the controls and displays. The SL-2 Science Pilot (SPT) commented in detail on his reach envelope Bt the ATM C&D station while using the chair (Dump Tape 154-03). The SL-2 SPT further states that the ATM C&D in his opinion was designed to be worked in a one-g environment (Dump Tape 155-12). He goes on to say that they did not want to sit at the C&D station, but neither did they want to stand on the foot restraint. 2-317 During the SL-2 crew debriefing, the CDR and Pilot (PLT) said t~at the ATM integral panel lighting gave a nice effect when the MOA floodlights were shut off, but the lighting was not necessary. When the floodlights were turned on the ATM edge lighting effect disappeared and I'lhen the ATM lights were used alone they couldn't .ead the checklists. The crew further stated in their debriefing that, because of the similarity between the SOB2A and SOB2B panels, control and displays on one panel were often mistaken for those on the other panel. The Sky lab 3 crew in all their comments about the ATM crew station indicated that they preferred to use the triangular grid foot platform alone without the ATM seat/backrest assembly. The SL-3 CDR gave a complete description of how the crew arranged their checklists and portable equipment around the ATMwork station. He also said: '~e know where everything is and - I think that works pretty well - it's a nice area to use." The SL-3 CDR further stated that it was really pleasant to work the ATM. (Ref. Final Dump Tape 251-11) The SL-3 SPT evaluating the ATM work station stated that the foot restraint at the ATM work station was very adequate and worked well but added that the lighting was poor for reading or updating checklists. The SL-4 crew also conSidered the ATM foot restraint to be very adequate. They did not consider the ATM seat/backrest an acceptable work station restraint. The SL-4 crew preferred the freedom of having just one foot fastened to the restraint and the shoulders and body unrestrained. The SL-4 SPT made one comment saying that he would have liked the foot restraint to be just a bit lower (Dump Tape 022-06, Pg. 13 of 24). No other comments were located to suggest thst other crewmen would lrke to have had a lower platform. The SL-4 crew, explicitely by the SPT, made sugges- tions that th& addition of a trash bag at the ATM station and in general. !I bag in the MOA would have aided operations in the MDA (Dump tepe 36l-03, Pg. 4 of 17). (2) EREP C&D Crew Station - The SL-2 crew operated at the EREP C&D station as planned, and no major pro- blems were indicated, however, the arrangement of the experimel,t controls (from top to bottom: 5192, 5l9l, 5190, 5193, 5l94) was a source of minor irritation. The 5L-3 CDR and the PLT gave evaluations of the EREP crew station. The CDR said (Final Dump Tape 251-11) : "The foot restraint there, that's the greatest thing since pop,corn." The 5L-3 PLT's comment on the EREP crew station was; "You've got to have the ability to get your feet locked down at the EREP panel. The C&D does have that ability. It's easy to work that." The 5L-4 comments were very similar to the 5L-2 and 5L-3 commen.ts. The EREP C&D crew station posed no problems and again the foot restraint was considered a very adequate restraint (Dump Tape 365.07, Pg. 3 of 21). (3) EREP VTS Cr~w Station - The kinescopes of the VTS passes sh~~ed the ease at which the VTS operator acquired and tracked the target site. The SL-2 crew described the VT5 as working better than the simulator. They did feel, however, for fQture designs a wider field-of-view would be desirable. The only bothersome problem on the 5L-'2 mission associated with this crew station had to do with the clipboard mounted on the EBtP experiment 5191 closeout cable cover. The clipboard was attached to the cable cover by two snaps and was utilized to hold checklists, maps, photographs of target sites, etc. The clipboard came unsnapped several times when used by the crewman. 2-319 I E Ii -I t: I! \ The significant comment the Sky lab 3 crew made relative to the VTS crew station · .. as the lack of a foot restraint for the VTS operator. The CDR said of the work station (Final Dump Tape 2S1~11): "One of our biggest mistakes in EREI' I'as not having one of those (foot restraints) fo~ the VTS. Sure you can hold on by your hands, but then you can't grab your map cause you are holding on." As with the SL~3 crel~ the S~4 crew thought that the VTS station needed a foot restraint (Dump Tape 36S~07, Pg. 3 of 21): CDR: "I think we need more of the grid~work sort of thing, like the AIM COD and the EREP C&D foot grid restraints. Those are very, very useful and very versatile and very handy •••• I think the VTS Operator needs some sort of foot restraints. The way it's working right now, you ~ we're wrapping our feet around the restraint system that holds the - the elephant trunk that goes OVflt' the s ill into the Command Module down through the tunnel, the AID." (4) MS12/479 Materials Processing Facility Crew Station~ There was littl1 S~2 crew comment on this experi~ ment station, The S~2 crew did not report using the MS12/EREP foot restraint in the MS12 position. In review of the S~2 kinescopes it was noted that the suit which was stowed near the MS12 operator's head appeared to cause minor infringment into the operator's work space. Stowage of a suit in this ares was not nominal and was assumed to have resulted from stowage constraints due to the extra equipment brought up for the repair operations and the early EVAs. Also, it was seen from viewing the S~2 kinescopes that the furnace door evidently had some unanticipated forces acting on it. The door would not remain open, causing minor incon" venience to the operator. The MSl2/479 crew station appeared to have adequately provided for the tasks performed by the crew. The S~2 crew stated in their. debriefing (14"117) that using the MS12 was just like working on the trainer. 2"320 ---- --_._-- -_ ... _._ ... ------ , F i (5) The only reference to this station by the SL-3 crew was during the crew ~.nventory. The CDR pointed out that the MS12/EREP foot restraint was in the MS12 position to perform the MSIB experiment operations. The MSIB Multipurpose Electric Furnace Experiment was the only MS12 series experiment that was performed by the Skylab 3 crew. Therefore, this crew sCation was not heavily used by the SL-3 crew- men and did not receive a significant evaluation on this mission. The most significant comment from the SL-4 crewmen concerning the MS12/479 Materials Processing Facility crew station come from the PLT (Dump Tape 356-010, Pg. 15 of 17): PLT: ''When you use the foot restraint for 512 it's not very good. It - in fact I stopped using it, it was so bad, I could get along better without the thing. It holds your body in the wrong position." However, the PLT did say that the station was operable without the restraint. MIlA Module Work Station - The SL-2 CDR (TAB 154-02) stated that there was disorientation upon initially entering the MDA from the AM early in the mission. The SL-2 SPT (Dump Tape 155-12) stated that the MDA size was very good for hanging onto things, but that it was not too good for traffic, in that if two crew members were working in the MDA the third had problems getting past them. The add-on type evolutl.on of the MDA module layout generated such descriptive crew comments as "hodgepodge" and "boiler room". The SL-2 PLT (Dump Tape 159-13) stated: "Orientation is all right, I've come to learn to accept ic during training. The general arrangement is kiIld of helter-skelter and hodgepodge ••• lt's not good, you come in here and things are - you have trouble finding things in here ••• The volume is good, more than adequate." 2-321 .. - ----,- The crew preference was strongly in favor of a one-g floor-ceiling orientation of spacecraft nlodu les • This was evidenced by conunents lik~ the CDR' 8: "Trouble with the MDA is it's not oriented like a room ••• Also by having circu lar rooms, YO'J end up having a prob lem knowing where different cabinets and things are stowed. It's much better to have rooms, like dO\m in the workshop where you've got a floor and you've got cabinets; you've got certain places to put certain things, and it just seems to work better." The floor-ceiling orientation seemed to be largely a I118tter of crew preference rather than an opera- tional necessity. The fact that the crew had no problems working in the ~mA was pointed out by such conunents as the S1.-3 CDR's (Final Dump 'rape 229-13): , "Now this is certainly acceptable for what we're doing. We don't have allY trouble in there except bumping into each olher unless things accident ly slide into spots and maybe, who knows, msybe that's a thing of the future. But right now, my feeling would be that you want to stick to something that you put things of a similar nature in the same place: Put all stowage against one \~all; put all this against another wall; put all the equipment in a little corner. In other words, it gets everything in a spot where it can be useful and not have to try to hunt for it." 'fhe S1.-3 PLT expressed a similar opinion about improving the arrangement in a cylindrical vehicle. lie said (Fina 1 I: .. op Tape 232-05): "Next Uille we build pomething like that \~e ought to I118ke it so things are faired in better and there's not so many nooks and crannies for stuff to get lost into, so msny head knockers and sharp objects sticking out from lack of things to grab on to and to fas ten yourse 1£ down to." 2-322 In evaluating the total volume of the MDA the SL-3 PLT said (Final Dump Tape 232-05): "The volume of the MDA is probably about right, but it's so cut up it's herd to really evaluate the volume in there. The volume is, in my case, is unusable becaUBe its small sections of volume tucked down behind boxas and around boxes. And a lot of volume in the MDA is not available for use. " The SL-4 crew was the first Sky lab crew to describe to Borne degree the MDA arrangement as having other than s "hodgepodge" or "boiler room" effect. Comments relating to the MDA by the CDR are as follows: "MDA/STS, general arrangement and orientation of compartment, I would say given the Bize and volume you got to work with, it's rather well oriented and arranged and compactly done so; the vol.ume is acceptable. adequate." (Dump Tape 356-05, Pg. 17 of 19). "The MDA is fairly adaptable it's kind of crowded there." Pg. 2 of 16). to other uses, but (Dump Tape 347-11, Comments relating to the MDA and STS by the PLT are as follows: "Boy. both of those are so lousy, I don't even want to talk about it until I get back down to the ground, because every time I think about how stupid the layout is in there I get all upset. You can't evan find numbers on panels • • • That MDA is reai'ly bad." ,(Dump Tape 356-06. Pg. 14 of 17). Although the SPT did describe the relationship of working spaces to stowage spaces in the MDA as a hodgepodge, his additional comments are as follows: "Now there!s one thiDS I do like about it. General srrangement and orientation of compartment, Come people, I guess, do knock it, but I kind of like having the walls as working space." (Dump Tape 361-03, Pg. 3 of 7). "That's one feature I do like about the MIlA, is that at least they co-manage, it seems, to use up all the wall!!. The walls are the working area. (Dump Tape 361-02, Pg. 6 of 6) The SL-4 crew also experienced difficulty in locating panels and stowage locations in the MIlA. Typical comments noted are as follows:' PLT " ••• This is one of the reasons that they got in trouble - of course they just didn't make the numbers big enough in a lot of cases." (Dump Tape 365-10, Pg. 14 of 22) SPT "The MDA/STS is one of thc biggest mysteries of the world w.len you go in there to find a panel ••.• Tha guy - when he did that, it looks as though he ,just kind of flipped numbers up in the air and s." charts and checklists. (4) M512/479 }mterials Processing Facility Crew Station- In accord ',ith the concept of negative reporting the laclt of SL-2 and SL-3 crew conuuents on this cre", station indiCated satisfactory perforllumce. The SL-/. comments concerning the H512 tOOt restraint should again emphasize a need for a foot restraint at each "ork station and the possibility of designing a restraint "ith position flexibility for compli- menting different cre_cn, (5) MDA Module \~OI:k Station - The }IDA evolved from a multiple purt docking adapter to include experi- mentlll and stowage provisio\ls. This evolution generally entailed "add-on" of an item at a time and was governed by a "minimum impact" groundrule. Consequently installations "ere made where space and system interfaces were readily available. Crew convenie\lce and optimum work station groupings of equipment were compromised. The addition of stowage items to the }IDA continued following c:use- out of the (MS. This mode of evolution in the development of the MDA configuration resulted in a somewhat disassociated arrangement of the ~IDA installed hardware and equipnvmt. The performance of the Sky lab crews proved that man can function effectively in a cylindrical spacecraft module with a z"ro-g orientation and layout of hard- "are. There eXisted, however, a longer per'.od of adaptation to working in the cylindrical layo\t of the }IDA than the floor-ceiling layout of the crew and experiments modules in the (MS. Each of the Sky lab crews thus far expressed a problem of orienta- tion when arriving in tl,e ~IDA until they found a 2-326 ~i i ~ t ;i " P f' ~ ,. I , , f-' ~. t - familiar piece of experiment hardware to key on. ~Iost crewmen found that they used the Ant C&D Pand or the EREP experiment hardware to orient themselves in the MDA. It also took the crewmen longer to locatlll a particular stowage container in the ~IDA than in the OWS where the stowage containers are laid out in floor to ceiling shelf-type cabinets. Each of the Skylab cre,~s felt the volume of the ~IDA was good for working in and hanging onto things, but expressed problems with traffic when two crewmen were working in the MDA and a third crewman tried to get past them. The volume of the MDA, 17 feet long and 10 feet in diameter, was suitable for its functions as a mUltiple docking adapter to a larger space station and experiments/stowage module. The volume ideally should be larger for a module similar to the MDA that is used as a single space station experiments module for a crew of three. The floor-ceiling layout of a spacecraft module was preferred by the Skylab cre'~11 but more than prefer- ence, the floor-ceiling layout is more efficient. The Skylab crews aJapted faster to the floar-ceiling layout and were able to locate stowage containers qUicker than in the cylindrical layout of the MDA. This would suggest that in future spacecraft it would be efficient to layout experiment and stowage hardware in a one-g ori~ntation even in small cylin- drical vehicles like the MDA. At the very least the early design concept for a small cylindrical vehicle like the MDA should provide for functional grouping of similar hardware. Stowage containers should be grouped along one axis like the OWS experiment com- partment stowage containers, or around the radius in a particular location like the ring lockers in the OWS. In the development of future modules of this type, opportunity for a more analytical, systematic design approach to crew integration considerations should be afforded. The design process obviously should include application of established human factors technique!! and sUlslations utilizing both ~~e-g mock- ups and a neutral buoyancy facility to develop optimum crew interfaces with the installed equip- 2-327 ment and systems. Future design concepts would capitali£e significantly on the experience and crew insights to be gleaned from the Skylnb missions. 2.2.9.2 Stowage A. Design Requirements - For the purpose of normal and con- tingency resupply and to support specific operational equipment, a number of items were required to be stowed on Skylab. To acco- modate these items, stO\~age containers were designed to secure and protect the stowed equipment from prelaunch, launch and docking loads and to provide convenient locationB for orbital. storage. Specific requirements for latches, restraints, operation, inter- faces, sharp edges, etc., are set forth in the following documents. • Contract End Item Specification, CPll4Al000026, Rev. E • Human Engineering Design Requirements for AAP, 10M32447 B. Functional Description - Flight crew equipment, consisting of communication equipment, tools, film magazines snd cassettes, camera filters and assorted experiment equipment and supplies were stowed in the MDA in forty-three (43) different stowage Locations. Th·j MDA was assigned a block of stowase location numbers from 100 thru 199, inclusive although all of the numbers were. not used. To differentiate stowage numbers from panel numbers, the prefix (M) was added to the stowage numbers. A total of 418 items were stowed for launch in the MDA. }Iost of the items were stowed inside con- tainers which were designed to provide restraint and protection for launch and docking environments as well as zero-g restraint once the container was opened. The film vaults additionally provided radiation shielding for the ATM film contained therein. One panel location (SIA 131) provided stowage for two dust caps. Fifteen of the stowage locations were containers. The remain- der were wall-mounted locations, use locations or experiment loca- tions. The containers utilized basically four types of equipment restraints: • Equipment nested in Mosites foam (Ref. Fig. 2.2.9-8) • Equipment stowed between partitions padded with Mosites foam (Ref. Fig. 2.2.9-9) e Mechanically clamped and secured with Calfax fasteners (Ref. Fig. 2.2.9-10). I I I , i I fr'" ':';' . ',,",: ; !<~I . !<;4 , ",'N I / ... ; ;.~:~,. 7~ 3 "_1._0 / 9-8 -Figure 2.2. Nested Eqt".ipment -;,' ':. 'tes Foam in Mosl. "" I '" '" o 1 F~fj ·z 1.-' -, .,.......-r .z ( ) l. (:.vow,,,, ~r:_WJ{"A. "t ....... ;(~: ... _~1- ..... ~I'-JC:II_.pq.1."'~· v:.t-q ...... ~-II ~::.tIl:>t: JUElJ: .... II "F.-'li''"-'. '. \ :J':L!"'_',fi'lf" 'I'.u')<.n , ... ' .,t"~:' .-.9I"I:""~~ ~,. ~ ~':.~, .-,<,r. " : - - '., "_, E, ~""': .... <'-"':! ~".,~~, . .' .... ............. T: '.:"-~"F." xc.;: r~~·~~ ~~~=.:.~ I? OO'A;> .,...H .... ..,.,.. L~-=~:~~:~::'~·""- .... u_ .... __ ~~ _'._ ......... _ '" ;::::::::':::''''::;':':1 f .. ""~.,,,,"~ .• ~""",~s=i .. ..., ..... ~ ':9(!~J •.IJf ___ / .i-JoX..~< Figure 2.2.9~9 - Equipment Stowed Between Partitions Padded with Mosites Foam j i i I -j N I W W t-' I • ~WD -. • ,-- fIOTES' fi::>. tOI>'J\.I£ All K"ObS '!"'l09~-' cq"E AS.;'~, ... tt .. ~S vtLT,t. c<"\CAt "O .. O'T£I; .. 9~"'O_rl' ""'HC, [ ..... £"~ POPT '.'·US 10 <:61.t'(I.t~-' ",S''". cOvE:>, ","""'OR1 '. ".,l[[-, '15"'00;88 Q, ... 't. c.AUP"':· 12 '.t"; ... 'O~!')- I S~~"C"'T ~~sv-S"""U: rL""'''''SII.Jh' 13 ~"".Zl -' cCVE~ HEAr S'''~ "',,"~~c- r .. sst. ~l!EII ::l','n':H IS 9'''''::10-1 ~l~"E""'SS'l'. Sf'"flE:I?f:FGfiI/IIlHG (2. Pt. .. ccs) 'f <'~"-'164_1 "'LH:" A1SY~ I 11 ~!y 'f.~-; F'lltr..!;$y .. nz r~ 9~"'l.ca, (..1" .. ~~~ v"';.ouu ~L;;""'EII: .i p, .. ~c tg 9~"'Ii:':U~" .~':;', ~OV[II.r~'lOO lI(,.n 20 ~~"'::'O~I-I ""';Y, "hi "U~1I0" , -1-1 ¥-~ ~TI'" "lL{ASE rfUZ$l-00t' __ '" Figure 2.2.9-10 - Equipment Mechanically Clamped and Secured with Calfax Fasteners • Equipment with clevis/lug interfaces secured with expandogrip pin (Ref. Figs. 2.2.9-11 and 2.2.9-12) There were a variety of container door latches, hinge fric- tional devices, and equipment restraint designs. There were several last minute stowage items added to the MDA after the vehicle was on the launch pad. Two spare water heaters were mounted to a plate that was added to the outside surface of the door of film vault No.2 (M152). r"o Scientific Airlock (SAL) window-covers were added to the M5l2/EREP foot restraint (M127). An EVA hatch window cover and the S183 kick plate were attached to the ATM COD console foot restraint (M17S). One earth terrain camera magazine was added to film vault 3 (M143). A complete listing of MDA stOl,age may be found in the Skylab Stowage Locker List (MDA) #1-SL-012 which lists the items by stow- age location number or Ifrl-SL-007 which lists the items by stowage list item number. C. Test - Final stowage of the ~IDA was accomplished by per- formance of test and checkout pt'ocedures (TCPs) KM-30l4, KM 7000, and test preparation sheets (TPSs), written in real time, to accomodate revisions to the original stowage plan as well as last minute additions. The MDA Stowage Installation Drawings (SK820000l00) were used extensively detailing and clarifying the TCPs and TPSs. No waivers were reqUired to be written, although 273 deviations were written against TCP KM-30l4 and 101 against TCP KM 7000. D. Mission Results - B .. ~ad ,)n all reports available, the overall stowage program was elltirely adequate and went smoothly. No launch stowage anomalies were reported by the crew; everything was secure as stowed when the MDA was activated. The sticky back Velcro strips were the only temporary stowage/restraint devices reported to be totally inadequate throughout the entire spacecraft. The Velcro which was bonded to the vehicle before launch performed satisfactorily. The crew stated a disli;,e for the dialatch fast- ener. Although swelling mosite was a major problem during the altitude chamber test at St. Louis, the subsequent modifications made to such containers proved excellent as stated by the crew at their debriefing of July 1973. During thc SL-2 mission, des towing and restowing of headsets, IWCCUs, film magazines, cassettes, etc., from the 15 MDA stowage containers went "as advertised". 2-332 i '" I '" '" '" H-ALPHA-I FILM ",u;.o.zll .. £ 5Q1roII13Ie9 H-AtPH.t.-1 HMo..E ASSY 5OMIS806 3 PLACES FILM vAULT (/,of) )24 PAllET I (ABLE CONTAINER) a2OOOO40010-019 -J Figure 2.2.9-11 - Equipment with Clevis/Lug Interfaces Secured with Expandogrip Pin I I I I I I ! , I I Figure 2.2.9-12 - Equirment with Clevis/Lug Interfaces E. Conclusions and Recommendations - Standardization of latches and hand operated fasteners related to stowage compart- ments should be of prime concern for future spacecraft design. Customizing of latches and hand-operated fasteners should be avoided in favor of off-the-shelf products to the maximum extent possible. Use of the Dialatch type of latch should be avoided as these were considered too co~plex and awkward to operate (and too numerous per cont&iner) by both the SL-2 and SL-3 crews. Cal- fax fasteners need to be improved with regard to the reliability of the retainers intended to keep them captive. Containers or drawers stowing like itews of varying sizes such as toolb should be designed to present these items in order of size to expedite selection of proper item, i.e., allen wrenches, sockets, and screwdriver bits. Attention should also be given to categorization of tools with respect to their application. More temporary stowage devices should be provided in the spacecra€t of the future rather than requiring the crew to impro- vise. In conjunction with gener~~ temporary stowage devices, the design and location of planned operational temporary stowage aids should be considered. 2.2.9.3 Habitability (Comfort Evaluation) A. Design Requirements - (1) Noise - The design requirements for the MDA noise levels were detailed in the Cluster Requirements Specification, ~ppendix A, Paragraph 2.l2.2a. Sound pressure level limits were identified for varioUs "requency ranges including an overull internal sound pressure le~el no greater than 72.5 db when the summation of the individual sound pressure levels from all sources is considered at any given time. (2) Illumination - The paragraph below was taken fro~ the CRS, Appendix G, Section 2.8 and gives the general crew systems lighting requirements. The details of the interior lighting requirements were presented in Section 2.8.1 of the CRS. "The lighting system shall provide general interior lighting during the mission tQ allow the crew members L~ locate; operate, and read all displays, controls, and nomenclature, to provide visual access to interior visual sur- 1-335 ,---------~.------.-.- faces, allow storage and retrieval of all articles of crew equipment, and provide for location and orientation. of the crew n~mbcrs within the various crew areas." (3) Thermal and Atmospheric Habitability - The MDA Crew Thermal Design requirements were called out in the Thermal Comfort Toleran~e Design Criteria BRO DB- 57-67, Rev. B. The crew comfort criteria was deter- mined by a "comfort box" area on a plot of wall temperature versus air temperature. See the Thermal Cont::ol System, Section 2.2.3 of this report for a plot of the comfort box. The maximum surface touch temperature of 1050F was also specified in the above referenced design criteria document. The air flow velocity design requirements for crew systems was defined in the CEI Specification CPll4A1000026 which specifies velocity at the MDA crew stations of 15 to 100 fpm. B. Functional Description - (1) Noise Sources - The primary sources of MDA internal amLient noise were the three circu~ation fans and the Rate Gyro Six-Pack. Intermittent noise sources emanating from the MDA were the EP~P (S190 Camera Array) and the Nuclear Emulsion experiment (S009). However, the predominant source of noise in the MDA emanated from the Rate Gyro Six-Pack which was installed in the MDA by the S1-3 crew. Also contributing to the MDA internal ambient noise was the Airlock Module's Environmental Control System. In this system the noisiest sources were the Molecular Sieve fans and the Cabin Heat Exchange Module fans. A cluster wide analysis of noise sources was con- ducted which effected the development of acoustic mufflers for the MDA circulation fans and produced predicted on-orbit noise levels. The predicted ambient noise level in the MDA (including noise sources in the AM but excluding intermittent noise generated by experiments), with all MDA circulation fans operating at high speed was approximately 60 decibels overall. 2-336 1 .' r \. ~ " Ii IT 11 t: , " ~ 1 , "', ~ l' (2) Illumination - The interior of the MDA was illumin- ated by eight interior floodlight assemblies that provided an illumination level of five foot candles (fc) minimum at the ATM Control and Display (C&D) console, EREP C&D console, and experiment MSl2 work stations, and a general illumination level of 3.5 fc minimum when measured along the X-axis of the MDA. The two lights nearest the ATM C&D console were provided with removable light attenuators. Each of the eight lights had a local switching capability of "OFF", "lAM", and "HIGH". The above stat.ed illumination levels were met with aU lighLs on "HIGH". A switch for on-off lighting control of all ~IDA lights was prOVided near the axial docking port of the MDA. (3) Thermal and Atmospheric Habitability - Three cabin heat exchangers located in the STS provided cooling to the MDA/STS area. Three circulation fans locatea in the MDA provided air circulation for the MDA and the CM interiors. Each fan could. be operated at high or low speed or could b~ turned off. Two of the circulation fans had their inlets and outlets in the MDA with adjustable diffusers at the outlet. The third fan forced air through a removable duct into the Command Module interior. Thermostatically controlled electric wall heaters could be set to actuate based on MDA air temperature in either the 70~ range or the 45~ range. An air temperature sensor was located at the inlet to the "CSM" fan which provided telemetrtc data. There was a ground capability to select, through telemetry, the heating range. The integrated sys- tem (wall heaters, air heaters, circulation fans and control systems) was designed to be capable of keeping the MDA atmosphere within a prescribed astronaut comfort: range. This range assumed the astronaut had some capability to adjust to the temperature through clothing, metabolic rate, and circulation fan control. C. Test- (1) Noise - The Skylab crews during prelaunch tests made a few subjective comfort evaluations of individual noise sources and found all MDA noise sources accep- table. See Section 2.2.2. Environmental Control System. of this report for sound pressure level test results in the MDA. (2) Illumination - The one lighting test performed with the flight lights resulted in the crew stating that the light levels were low but acceptable. See Section 2.2.4.3, Lighting, for illumination test results. (3) Thermal Bnd Atmospheric Habitability - There was no subjective evaluation by the Sky lab crews of temper- ature and air velocity in the MDA during prelaunch tests. See Section 2.2.3. Thermal Control System, and 5b~tion 2.2.2.1. Ventilation System. for pre- launch cest results of temperature and air flow. D. Mission Results - (1) Noise - During the SL-2 mission. noise measurements were taken by the crew (Dump Tape 152-05). The overall sound pressure level (reported as "ambient noise level") was 53.5 db. The SL-2 PL'r evaluated the MDA noise level as satisfactory. but stated that it got high when EREP was operating. Comments and evaluation by the SL-3 crew indicated that the noise environment throughout the cluster was quite comfortable. On Dump 'rape 230-03. Page 3 of 3 on mission day 22. the Sr~3 pilot commented: "Noise levels are all satisfactory everywhere." Later on mission day 24. the SL-3 pilot further elaborated (Final Dump 'rape 232-07): "Noise level is quite low. It's higher in the STS area than anywhere because the fans on the mol sieves sre running but otherwise it's quite quiet. There is no objectionable noise. It just hums along with a very comfortable noise level. That's throughout the whole spacecraft ..•• so I don't have any complaints about the noise at atl." 2-338 I: I , ! ~ .. ~ ----- Commentary relative to the noise induced by the rat~ gyro six-pack was provided on minsion day 49 and appears on a transcript of the communication, wherei.n the pilot' s ans,~er to a query from Cap Comm was: "No, I wasn't turning anything on and off, Bruce, probably the rate gyros. They do a lot of humming back here and that's the thing that makes the most noise up here in the MOA, when EREP is not with us." A comparison of the sound pressure level measurements recorded by the SL-3 crew and the internal noise spectrum shape over nine frequency ranges specified as the design goal maximum in the Cluster Require- ments Specification, MSFC Document RS003M00003, substantiated the subjective evaluation describing a comfortable noise level environment. The SL-4 crew reported that unacceptable noise levels in the MDA affected them in areas of communications, concentration and work as explained in the following crew comments. CDR "Noise: ••• has affected our recordings. And the people on the ground have complained on several occasions about the recording situation and the fact that there's a lot of background noise." (Dump Tape 365-07, Pg. 4 of. 21) 8FT "Noise: ••. I find that it gets to me when I'm trying to concentrate." (Dump Tape 003-01, 8PT Pg. 3 of 11) "The noise working in 3 of 11) used t· get to me when ,~e' re the MOA." (Dump Tape 003-01, Pg. Some sources of noise are pointed out by the SFT on Dump Tape 361-03, Pg. 6 of 7. "Aside from the pump which I mentioned, we've got rate gyros in there. And they're both making so much racket, I can't tell "hat noise level exists under either t"o of these." 2-339 .. , ;-...,.- ,..~- (2) Illumination - The 31-2 mission power problem caused the 51-2 crew to operate with reduced lighting in the MDA for a portion of the mission. The 51-2 PLT rated MDA illumination as adequate to poor (Dump Tape 159-13). The SPT stated, "Illumina- tion is low in the MDA and a little bit confusing in a circular compartment" (Dump Tape 159-12). The S1-2 PLT also said, "l'he lighting bugs me 11 little bit. I think the light level is too low ••• the color temperllture or quality of the light is too harsh .•• " (Dump Ta;>e 155.12). After splashdown, the PLT evaluated the MDA lighting as adequate but stated that since the first two weeks were spent with reduced lighting, when the lights were com- pletely turned on everything looked g~od. During the S1-3 mission power-down requirements impose" on S1-2 as a result of EPS (Electrical Power System) anol1l81ies were not necessary. How· ever, crew comments indica ted that in genera 1 they still felt the lighting levels should be increased. Some trouble-shooting and maintenance tasks required the crel;' to work in out-of-the.way places ("Nooks and crannies") where adequate lighting could only be provided by handheld "lashlights and penlights. This prompted a recommendation for head-mounted lights I;,hich would leave both hands free to per- form the desired task. For a short period during 51-3 lighting within the }IDA was somewhat restricted uue to an outage of aft floodlight assemblies 2 and 4. The general impreSSion regarding cluster illumination was well summed up in the following comments expressed by S1-3 pilot in Tag Tape 232-07, Pg. 5 of 7: "Okay, illumination seems to be generally a little bit low. It could be higher everywhere, I guess, although we're able to accomplish our work with the illumination that we have •• , Just to work around in here and throw switches and so forth, it seems adequate, but if you want to read a boole or something, it's best to find yourself near the window or something like that so that you've got illumination. But for just working and moving around and doing your job, why the illumination is adequate although it could very easily be higher and make every- body happier." The subjective evaluation of the SL-3 crew that the cluster illumination level should be increased reiterates the recommendation expressed by the crew of S1-2. Lighting levels we~e apparently adequate for the performance of scheduled tasks. The S1-4 crew was somewhat more tolerant of the illumination level than previous crews as the following comments indicate. CDR "Illumination in the airlock MDA/STS more than adequate, quite adequate." Tape 356-05, Pg. 18 of 19) is - is (Dump PLT "Illumination is satisfactory." (Dump Tape 356-06, Pg. 15 of 17) SPT "Adequacy of lighting. No problem." (Dump Tape 025-05, Pg. 7 of 28) (3) Thermal and Atmospheric Habitability - The S1-2 mission habitability of the MDA was affected by the total Sky lab thermal and power problems. The S1-2 crew wore their jackets at times when working in the MDA because the heaters were kept on low range to conserve power. The thermal problem in the OWS caused PLT Weitz to sleep in the MDA for two nights until the sleep compartment temperatures cooled down enough to be comfortable. The S1-2 crew said that the air flow in the MDA, as in the whole Skylab vehicle, Was excellent. The CSM fan was operated almost con- tinuously to provide air flow to the CM while the MDA area fans were used as required when the crew was working in the MDA. A unique feature of the zero-G air flow system is its ability to transport items to the intake duct of the ventilatioh system. The foUCI,ing comments express some crew thoughts. These comm~nts were made at the S1-2 Technical Crew Debriefing June 30, 1973. CDR "Any time you Ilre handling a lot of lit t 10 piocus of stuff, y\ll\ reu11y havo to tako your til\\~ <11' you 1<111 lose it. The "ay the circula- tion system 1M!! blo"ing ail' into the Conulland Hoduln, if somllthillS sot al~ay frolll you Ilnd you didu 0 t see it, it \~ould quickly be up ill tho middle of the NDA. This I~as bocause tho air- f 10\~ I~as \lut the tunnel. 1'he duct b le" it dOlm the side of t:he tunnel and ducted it ill. Thore I~ns a nice little flO\~ dOlm the bottom snd right bllek oul. If somethit.~ got out in tho middlo of the cOIl.unt,d module y,)U "ould look out and BOO that the thing "ould be 15 feat dOl'"' there i.n tho ~IDA heading for the "orkshop." 1'he follo"illl; conversation occurred at the samo de- briofing as abovo: CDR "But as soon as fans lire going ill then1, that circulntion "ystem cauBes ovet'ytiling that 0 s flontins to line up on a fnn screen somcplnce." SI''r "'1'his is n very good desiSt\ point in the vehicle. You don 0 t lose things. If it 0 s properly closed dO\m nn:1 you have good fails, eve\,ythi.ng winds up on n scrcan." PL'f "'fhat 0 s right. I,e agonized a lot, especially Bob OVel'\1\cyer 0\\ thoso closeouts in the ~IDA. But it I~as worth it. because it kept stuff from getting lost bacl< thOll"a." 'rhrough telematl"y the Imll temperatures and air temp- el"atures in the ~IDA \~ere monitored 011 the ground mId the plotting of lIir versus "all temperatura revealed that the ~IDA DIet thf,\ design comfort bolt cril:eri/\ for only three· days of the SL-2 mission. 'rhe reason for this I~as that the ~IDA I~all heaters I~ere kept off to conserve electrical 1,0\~er. Reviel~ of the SL-3 cro" COtlUlIcuts and subjective tlvaluations indicated that the thermal environment "liS ossantiall>' quite comfortable. 'rhe 81-3 PL'C in a H4B7 Habitability E: I t.> .;- .., I- VHF I UHF 8-190 MULTISPECTRAL PHOl'OGlIAi'HIC FACILITY ~i .9fm .5pm S 191 Im'BARED 8PEC'm.CtII'l:IIl ISSS ~~ 15.51'. 6.2J1a 2.41'm .4pm 8-192 iIllLTISPEC'lRAL SCAJlND. B 12.5r 10.21"" 2.351' m .411' m ~ 8-193 MICROWAVE RADIamTEIl/SCA'l."rBR<»mT1!Il/ALrnmTER 13.9 GBZ ~ S -194 L-BAlI]) RADIClfBTD. 1.4 TO 1.427 GHZ MICROWAVE I 8HF I I!IIF J VISIBLE I I' I ULTRAVIOLI!T t- L- lIAND -\. Au -lIIlNlJ 1 GHZ 10 GBZ I I I '2 I ) ,10 103 FRl!QUlNCY - HIIZ I I I I I 105 106 107 108 109 I I I I I I I I J MB'I1lS 30 CH 3CK .3 CK 300 30 3 .3 MICRONS MICIla'IS HICllttiS MICROIIS Figure 2.2.10-2 EREP Data Frequency Spectrum I (3) Cabling - MIlA cabling between sensors and the data electronics within the C&D Panel was required to handle the following capabilities: (a) Transmit analog signals from sensors to the C&D and Tape Recorder (T/R) with a maximum frequency of less than 0.2 Hz, with a voltage range from 0 to 5 VDC and 250 ohms, or less, source resistance. (b) Transmit on-off signals between sensor, T/R and C&D as required for display. (c) Transmit a 36 bit time signal from the AM/M1lA interface to the C&D. The signal was time multiplexed into an NRZ-L PCM format and run at a nominal bit rate of 8.192 KBPS. (d) Transmit DC power of the quality described in paragraph (7) below. (e) Transmit discrete control signals, as required, of three types: • Contact closure - sWitching for loads up to 0.5 ampere at 28 VDC. • Logic - differential discretes to provide the capability to operate properly with up to 10 volts DC of common mode voltage between the driver and receiver circuits. • Multidiscrete Level - voltage discretes to provide a voltage scaling network within the panel. (f) Transmit PCM NRZ-L wave forms at 0 & 5V from the sensors to the C&D Panel. Each PCN nignal was accompanied by a synchronizing signal, where required, at twice the PCN bit rate. The unit frequency multiplexed, or encoded the PCM NRZ-L signals as Miller Code. (4) oata Recording System - The EREP system required a capabillty to record and store data generated by the system. The data recording was accomplished by mounting t~o (one primary and one backup) magnetic tape recorders in the HIlA. The MIlA was 2-350 '" .<' •• : Jr." ",!, required to provide wiring between the C&D panel h~ and these TIRs for the following data transmission and control capabilities: (a) 1.0 MBPS Maximum - Miller Code Data - 24 lines (b) 60 KBPS Maximum - Miller Code Data - 2 lines (c) A composite signal consisting of one 200 BPS (maximum) PCM signal, one B KBPS (maximum) PCM signal and one 10 KBPS (maximum) PCM signal and one 10 KBPS (maximum) PCM signal; each PCM Signal frequency shall. modulate a Voltage Control Oscillator (VCO). The three VCO outputs would be mixed by mixer amrlifier - 2 lines. (d) Control signal to select servu controlled speeds of 7-1/2 and 60 inches per second. (e) Transmit Miller encoded or FM multiplexed signals from the Control and Display Panel for recording on magnetic tape. The bit error rate for these signaGs would not exceed an average of 5 bits in 10 • The MDA was required to provide for crew access to permit tape changing apd head and guide rollers cleaning, a shirt sleeve environment, and cooling of either TIR when manned (see item (5) below). (5) Special Thermal Requirements - The EREP System requireJ a liquid coolant loop to thelmally con- trol the C&D Panel, the primary and secondary tape recorders and the 5192 Electronics Assembly. This coolant loop was connected downstream of the ATM Control and Display Console coolant system and performed as a dependent part of that system. A means was required in the MDA to isolate the EREP coolant loop ·rom the ATM C&D Console coolant system. The EREP coolant loop required high purity inhib- ited water as the working fluid: (a) Naximum supply pressure: 37.2 psia 2-351 " .. (b) Maximum 4:. P from EREP inlet to outlet: 2.0 psid (\1 220 Ib/hr (c) Minimum flowrate: 220 lb/hr (d) Inlet Temperatures - EREP operating: +40"F to +81(\" - EREP not operating: no flow thru system (e) Maxim'.lm heat dissipation to coolant loop: 810 btu/hr @ 8lor inlet temperature The coolant 1uop was required to maintain surfaces of the equipment being cooled (which were like ly to contact the crew) between SOoF and 10SoF. The maximum allowable leakage from the BREP coolant loop was not to exceed 17 cubic inches from final fill to the end of a 240-day mission. The MDA wall temperature in the vicinity of the S192 mounting plate was required to be greater than 6SoF prior to operation of the S19l cooler. (6) Structural Requirements - The F,R£P system was constructed to operate after being subjected to the dynamic environments of the MDA. The NDA provided mounting space and crew restraints in a controlled environment. The MDA also provided mounting plates, trusses and windows for various pieces of EREP equipment. (7) Electrical R(lquirements - The MDA was required to transmit powar to the EREP system from the AN power system with the following characteristics at the experiment interface: (a) DC Steady-State Voltage Limits: 30 volts maximum at Zero power transfer to 24 volts minimum at rated power transfer. (b) Ripple Voltage LImits: composite ripple voltage, superimposed upc,! the DC steady- state voltage, not exceeding 1.0 volts peak to peak from 20 Hz to 20 KHz. 2-352 1m! S190 S191 (2) S192 S193 S194 (3) (c) Under Voltage: not less than 21 VDC returning to the steady-state voltage within one second under normal conditiops. (d) Over Voltage: not exceeding 33 VDC returning to the steady-state voltage within one second under nominal conditions. (e) Transients: transient voltage at the inter- face not exceeding plus or minus 50 volts with a pulse width not greater than 10 micro- seconds. (f) Reflected Ripple: reflected ripple meeting the requirements of MIL-STD-46l, CE 01. (g) Power Consumption: power consumption used to size the transmission system in the MDA system are given in Table 2.2.10-1 • . ELECTRICAL POWER - WATTS AT 28 VDC ~ STANDBY AVERAGE 580 60 153 (1) (2 sec interval) 85.5 (1) (8 sec interval) 72 (1) (20 sec interval) 481 90 150 266 124 117 300 59 131.5 35.4 20.4 35.4 C&D Panel 298 130 117.6 Tape Recorder N/A N/A 260 (1) Intervals shown are between camera exposures. (2) Includes the V/TS. (3) Includes heater power. Table 2.2.10-1 Er~p Po~er A11oc~tions 2-353 (8) Alignment Requirements - The mounting provisions of the M~ were required to keep the 1ine-of-sight (viewing axes) of the EREP data taking sensors perpendicular to the M~ X-Y reference plane within ±D.5 degrees. (9) Window Requirements - Experiments 5190, S191, and 5192 required viewing windows set into the M~ shell. The particular optical requirements of each window are specified in the paragraphs below. (10) Weight Allocations - The total weight: of the EREP system within the M~ was 2159 pounds. This was exclusive of the M~ cabling, windows, the Sl93 experiment .and film and n~gnetic tapes. (11) Thermal Allocation - The acceptable heat dissipa- tion required by the M~ atmosphere from the EREP system was 2740 btu/day. The heat dissipation from the EREP system to the EREP coolant loop provided by the M~ did not exceed 2740 btu/day. B. System Description - The EREP System is pictorially illustrated in Figure 2.2.10-3. The following (Table 2.2.10-2) is a list of the contract end items that comprised the EREP system: 2-354 EXPERIMENT S190 S19l S192 S193 S194 ESE (1) SUPPLIER NAME END ITEM ITEK S190 M/S Photo Ass'y 173200 Boresighted Camera Array 173150 Magazine Assembly 173160 Cassette Assembly 173155 Flight C/O & Support Equip. N/A MMC S190 Supplemental Hardware 220401A Block S19l IR Spectrometer Module PI--9 5016 7 Engineering Electronics Module PL-950l39 MMC S19l Viewfinder/Tracking Sys 22030lA Honeywell External Scanner Assy DJKllAl Radiation Internal Scanner Assy DLK79Al Center Digital Electronics Assy KHK9Al G.E. Microwave Rad/Scat/Alt 3240 AIL LCBand Electronics Box 375668 Microwave Radiometer 375584 Antenna 375667 MMC Control and Display Panel 22060lA Data Recording System 220l0lA ESE Subsystem 22020lA Table 2.2.10-2 EREP System End Items S190 Multispectral Photographic Facility (MSPF) - The S190 MSPF was a six camera system with a for- ward motion compensator. The six cameras had a matched distortion and provided photographs, in the visible and near infrared regions, of the earth's features. The specific objectives of the S190 MSPF were to : • provide a photographic facility to study the value of multisp'otral photography using various film/filter combinations for the identification and assessment of the earth, oceans and cloud features. • determine to what extent multispectral photo- graphy could be applied to detailed analysis in earth resources. 2-355 N . - ... '" '" S194 SI90 S19T & V/TS SECONDARY TAPE RECORDER PRIMARY TAPE RECORDER S193 S192 ELECTRONICS S 192 Figure 2.2.10-3 EREP Hardware Interfaces STATION 1 2 3 4 5 6 The S190 MSPF con"isted of a boresighted camera array with a Forward Motion Compensator (FMC), a Mount Support Assembly (MSA) and a viewing window in the HDA shell. (a) S190 Boresighted Camera Array (BCA) - The S190 BCA employed six camera stations, each using 70 mm film. The six camera lenses were distortion matched so that the impage points fall within a 20 Tan Q micrometers (tangential dimension) by 10 micrometers (radial dimension) elliptical envelope. The BCA was boresighted to position the optical axis of each camera station parallel to each other within a cone of 60 arc seconds full angle. The spectral region cove.ed, the film type used and resolution of each of the camera stations, are given in Table 2.2.10-3. WAVELENGTH RESOLUTION LP!MM ( MICROMETERS) FILM TYPE STATIC DYNAMIC .5 - .6 PanX Aerial 116 102 .6 - .7 PauX Aerial 130 115 .7 - .8 IR Aerographic 55 50 .8 - .9 IR Aerographic 50 45 .5 - .88 Ektachrome IR 45 40 .4 - .7 Aerial Color (S0242) 130 116 Table 2.2.10-3 S190 Sensor Specifications The BCA was capable of sequencing exposures from one frame every two seeonds to one frame every 20 seconds, controllable at 2 second intervals. 2-357 r ~ Q I E ~ ~ , 0 . 8 0 ""- 0/ / ~ " " 0 0 0 4 .4 .5 .6 .7 .8 ., 1.0 WAVELENGTH IN MlCROMETERS Figure 2.2.10-4 S190 Window Transmittance Requirements 14 13 12 II 10 , 8 6 5 .4 ,. .5 .6 .7 .8 ., 1.0 WAVELENGTH IN MICROMETER; Figure 2.2.10-5 S190 Window Reflectance Requirements 2-358 ---_. ~.~-.-... (b) S190 Window - The S190 window was mounted into the MDA hull and performed a photographic function, an astronaut viewing function, a structural function and a sealing function. The area of optical quality was a minimum of 13.5x19.76 inches with the following characteristics: • Wavefront Variation - Less than 0.06 micro- meter from original plane, less than 0.012 micrometers from best RMS fit plane (any 3 inch diameter area) • Transmitting 1/4 Figure 2.2.10-4 • Reflectance - Figure 2.2.10-5 • Parallelism - The exterior surfaces of the window parallel to within 2.0 arc seconds over the entire window area. The window was provided with external and internal covers. The external cover was mechanically operable from within the MDA. (c) S190 Mount Support Assembly (MSA) - The MSA was the member that attached S190 to the MDA shell. The MSA positioned the S190 camera array over the MDA window during launch, during sensor operation, rotated the camera array to a stowed position to clear the window for crew viewing and filter changes, and provided an intermediate position for camera checkout. Thp. MSA mounting in the MDA positioned the BeA over the center of the S190 window assembly during photographic operations with the optical axeS positioned within +0.25 inches of the center of the MDA wind~. The MSA was capable of holding the BCA such that the Forward Motion Compensation device (FMC) axis was perpendicular to the MDA X-Z plane within 0.060 inch and parallel to the window within 0.057 inch. (d) Functional Interfaces Description - The operation of the S190 experiment was controlled at the EREP C&D Panel, with the exception of certain basic controls wh'ich were located on the BCA. The S190 housekeeping and timing signals were recorded on magnetic tape by the EREP Data Recording System. 2-359 '. . 1 (2) S19l Infrared Spectrometer System - The S191 IR Spectrometer had the capability of acquiring spectra of small (approximately one nautical mile diameter) ground targets with a one milliradian spatial reso- lution from orbital altitudes of 200 to 260 nautical miles. The IR Spectrometer scanned through the spectral regions .4 to 2.4 micrometers (visible to near IR) and 6.2 to 15.5 micrometers (thermal IR). The acquisition and tracking of the specific ground targets was accomplished by the utilization of an astronaut controlled Viewfinder/Tracking System (V/TS). The IR Spectrometer had the same line-of- sight as the V/TS by the manipulat' ~ of a two-axes hand controller. Once the ground <~"get was being tracked, the EREP Data Recording System would record the spectrometer outputs. Concurrent with tracking the target and recording data, the V/TS provided the capability to take photographs of the target area. The specific objectives of the S19l IR Spectrometer were to quantitatively evaluate earth resources sensing in the above spectral regions from near orbit and to evaluate the use of an astronaut c~ontrolled tracking system to acquire ground sites. The S19l IR Spectrometer consisted of the Infrared Spectrometer, a Viewfinder/Tracking System and precision machined mounting plate, set in the MDA shell. (a) S19l Infrared Spectrometer Description - The S19l IR Spectrometer consisted of a filter wheel deSign utilizing circularly variable interference filters as the spectral bandpass selection elements. The spectral resolution of the spectrometer is shown in Figure 2.2.10-6. The IR Spectrometer completed one spectral scan per second through the entire wavelength range. The IR Spectrometer had full internal calibration in radiance, and employed sandwich detectors of silicon and lead sulfide for the short wavelength channel and mercury-cadmium- telluride for the long wavelength channel. The mercury-cadium-telluride d~tector was cooled to below 900 K by a closed cycle cooling engine. ~Kln 1O.2~_-:'::_-:-'::--:-':---:''::--::71-7---7--,:':---4.:---,L- 0.4 0.8 1.2 1.6 2.0 2.4 6 8 10 12 14 \lIiVRLENGTlI (Hlcr"",eten) Figure 2.2.10-6 IR Spectrometer Spectral Resolution Appropriate elec~ronics were provided to output the various signals in a form compatible to the 8191 pulse code modulation (PCM) system. The PCM system sampled each spectral channel (5) and the filterwheel angular position at a rate of 684 samples per second (SPS) and 31 housekeeping channels at a rate of 21.375 SPS. The PCM system had a 10-bit accuracy. A clock output was prOVided to a1.low the.PCM data stream to be Miller encoded. (b) S19l Viewfinder/Tracking System Description - The V/TS permitted an astronaut in the MDA shirt-sleeve enyironment to visually acquire a selected ground target, direct the field of view of the IR Spectrometer within the target area, then maintain this concition during one second of data acquisition. The system provided a structural/environmental enclosure for the externally mounted portions of the S19l Experiment. 2-361 'i I Key oharacteristics of the V/TS were as follows: • The magnification of the astronaut viewing telescope was adjustable between 2.25 power and 22.5 power. • The field-of-view ranged from 70 ± 4 nautical miles at minimum magnification to 7 ± .4 nautical miles at maximum magnification from a 235 nautical mile altitude. • The static ground resolution of the V/TS telescope was: Maximum magnification: On-axis 73 ft/cycle Maximum magnification: 0.850 from 105 ft/cycle the center of FOV On-axis 8.50 from the center of FOV. 660 ft/cycle 930 ft/cycle • The V /TS was designed for in-flight align- ment of the telescope line-of-sight to the IR Spectrometer ~etectors. • The V/TS had the capability to direct the line-of-sight 10 degrees aft to 54 degrees forward along the ground track and 23 degrees left and right measured from the +Z axis. These angles are defined for the center of the field-of-view with the entire field of view unobstructed. • The telescope field-of-view displayed time. gimbal angles. and an alignment light for V /TS and IR Spectrometer alignment. • The V/TS provided all controls and displays necessary for complete operaticn of the system. The controls and displays were located at the V/TS station. • The external environmental enclosure was equipped with an electrically operated aperture cover. The cover was designed to o open or close at a rate of 2.0 per second and had an automatic electrical/mechanical latching mechanism. 2-362 - .. ---~--~ "-----~"--.. ~---"--- l' , , f:, fj , " i j r, , ~ ! • The V/TS &ccommodated a camera, either TV or nata Acquisition Camera (DAC), and incorporated a pick-off mirror to allow the camera to photograph the field-of-view of the V/TS. It was also possible to dump photographic data to the ground via TV. (c) S19l Mounting Plate Description - The S191 mounting plate provided the internal and external mounting of all S19l components. The mounting plate provided feed through connection for transmission of all data, power and control signals between the various portions of S19l. The mounting plate also provided a viewing window (which was a part of the optics of the telescope gimbal mirror system) for the V/TS telescope and a thermal sink for thp. S19l Infrared Spectrometer. The window had, as a minimum, the following optical qualities: • Transmissivity - In the wavelength range from 4,000 K to 7,OQO X, a minimum of 95 percent transmission at normal incidence. An anti-reflection coating was provided. • Parallelism - 5 arc seconds or less. • Wavefront - Peak-to-peak variation did not exceed +- for .,. = 6,000 R over a total window a,rea. • Clear Aperture - Three-inch diameter, minimum. • Index of Refraction Variation - The index of refraction of the glass measured at ~ = 6&000 X would not vary by more than ± SxlO- over the clear aperture. (d) Functional Interface Description - The S191 equipment operation required two· crewmen (one at the COD for power, and spectrometer operation and Jne at the V/TS). All S191 data a19t:tg with housekeeping data, was trans- mitted to the C&D panel to be re~orded on magnetic tape by the EREP system. (3) S192 Multispectral Scanner - The Multispectral Scanner was capable of gathering high spatial I I I I i I !!!!!!! 1 2 3 4 5 6 7 resolution and quantitative line scan data on the radiation reflected and emitted by selected test sites. The data was taken in 13 spectral regions of the visible, near infrared, and thermal infrared regions of the. spectrum. The Multispectral Scanner could gather the dat.a in these spectral bands with a high signa1-to-noise ratio in a spatially registered manner. The data was digitized to maintain the infotu~tton content and spatial registration of the data as it passed through the system electronics to the EREP C&D panel and to the EREP recorder. The S192 Multispectral Scanner employed 13 detectors to gather information in the 0.4 micrometer to 12.5 micrometer region of the spectrum and separated the spectral information into the follOWing 13 bands: Wavelength (Micrometers) .!!!!ll!. Wavelength (Micrdneters) 0.41 0.46 8 0.98 1.08 0.46 - 0.51 9 1.09 - 1.19 0.52 - 0.56 10 1.20 - 1.30 0.56 0.61 11 1.55 1. 75 0.62 - 0.67 12 2.10 - 2.35 0.68 - 0.76 13 10.2 ~ 12.5 0.78 - 0.88 The S192 Multispectral Scanner consisted of an interna1.and external scanner, a digital electronics assembly and a mounting plate in the MDA shell. (a) S192 Multispectral Scanner Description - The external scanner was provided with a remotely actuated cover for the objective aperture. The instantaneous field-of-view (IFOV) for all detectcrs was 0.182 milliradian times 0.182 mil1iradian or 260 feet by 260 feet, from a 235 nautical mile orbit. The total scan overlap was less than 5% of the area scanned. The variations in the scan pattern were less than 0.1 times the dimension of the smallest IFOV in both the in~track and cross-track directions. The spatial registration. between \ I I ) , ! I , ii ! , I \ \ 1 i -!' ;1 n i, ! ~ • ! - I " \ , , (' ! I, i " , , --""'l'-'-- any two bands was maintained to one-tenth the dimension of the IFOV of the two bands. The angular coverage &swath width) was 1200 of rotation of a 5.5 of a half angle cone. The optical resolution of bands 1 thru 12 was such that the diameter of the blur circle of the optics was smaller than one-half the dimension of the IFOV. For band 13, the optical resolution was essentially diffraction limited. The Multispectral Scanner had a cooler/detector/preamplifier assembly replace- ment and realignment capability. The replace- ment assembly was stowed in the internal scanner assembly. The Multispectral Scanner had the capability to calibrate each spectral band radiometrically, once each scan line. (b) S192 Digital Electronics Assembly (DEA) - The DEA accepted the video outputs from the detectors and digitized/formatted this data. The DEA also distributed MDA power, controlled S192 gains and provided circuit protection. The output of the electronics assembly was 22 channels of digital scientific data and a single channel of housekeeping data at a rate of .970 megabits per second per channel. Each scan line (data frame) was divided into sub- frames with synchronization signals at the beginning of each frame and subframe. The Jigital data output was coded in pure binary and was then Miller encoded in the C&D panel before being recorded on tape. The DEA also digitized and multiplexed all electrical signals necessary to define the instrument status, at a rate of once each scan line; such as operating conditions and calibration source conditions. These signals were routed through the EREP C&D Panel at the same rate as the scientific data to be recorded by,the EREP Data Recording System. This housekeeping data was redundant!y recorded on T/R tracks 1 and 27. 2-365 . --:-~--. The electronics assembly also provided selected analog signals for display on the C&D panel. (c) S192 Mounting Plate - The S192 Mounting Plate provided for the mounting of the internal/ , external portions of the scanner. The mounting plate provided a thermal sink for the external portion and provided feedthrough connectors for all data. control and power transmission between the internal and external portion of S192. The mounting plate included two windows for sensor viewing. The window material for spectral bands l'thru 12 was T17 Infrasil I. The window had as a minimum the following characteristics: • Clear Aperture: 2.0 inches in diameter by 0.25 inch in thickness. • Transmittance: 93% minimum at any wave- length between 0.4 and 2.4 micrometers; 96% minimum at wavelength of peak trans- mittance; uniform within 0.5% over any 1/4-inch diameter. • Coating: Single layer of magnesium fluoride anti-reflection coating to both sides with 1/4 wavelength optical thick- ness for peak transmittance at 0.6 micro- meters per MIL-C-675. • Wavefront Variation: Variation not to exceed 1/4 wavelength for a wavelength of 0.6 micrometers over the total window area. The window material for spectral band 13 was germanium with the following minimum require- ments. • Clear Aperture: 2.0 inches in diameter by 0.25 inch in thickness. • Transmittance: 92% minimum average over the 10.2 and 12.8 micrometers; band uniform within 0.5% ever any 1/4 inch diameter. • Coating: Multilayer anti-reflection coating. to both sides • j ) I ! (d) Functional Interface Description - The S192 ExperUnent was controllable from the EREP C&D Panel and required only one crewman for operation during data passes. The experiment used 24 recording tracks of the EREP Data Recording System; 22 for sCientific data and 2 (1 redundant) for housekeeping data. The Di~ital Electronics Assembly was supported on equipment rack no. 2 and used cooling water from the EREP coolant loop. (4) 8193 Microwave Radiometer/Scatterometer/Altimeter - The 5193 Experiment was a combination radar alti- meter, radar scatterometer and passive microwave radiometer. The 5193 Experiment measured near simultaneously, the radar differential backscattering cross section and the passive microwave emissivity of the land and sea surfaces. The microwave radiometer and scatterometer were capable of oper- ating independently of each other and of operating independently of the altimeter. The system used a single antenna which was gimbaled to scan in various modes. The S193 Experiment also consisted of a gimbaled (pitch and roll) antenna and an electronics package mounted externa~ly. (a) S193 Microwave Radiometer/Scatterometer/ Altimeter Description - The 5193 System was designed to ~perate on a single frequency of 13.9 GHz. A single antenna was used for all operations. The antenna exhibited a pencil beam of approximately 1.5 degrees and was gimbaled to allow for scanning up to 48 degrees on ei.ther side of the flight track and 48 degrees forward along the flight track relative to the Z axis of the MDA. The system was electronically controlled from the EREP C&D P~nel to perform the various modes for the altimeter radiometer and scatterometer. In addition, the altimeter range gate was set from the C&D panel. The S193 electronics data output was digital and adaptable to a lO-bit word PCM format. It was 10 KBPS for the altimeter mode and S.333 KBPS for any radiometer/scatterometer mode. All data was redundantly recorded on the EREP Tape Recorder System, tracks 14 and lS. The flight hardware, antenna and electronics box, was provided for mounting directly to the AM IlI\ truss. (b) Functional Interface Description - The entire 8193 Experiment was mounted to the AM DA truss. It received power directly from the AM power bus. All 8193 controls were contained in the EREP system in the MDA. The AM also provided survival heater power for the unit. (S) 8194 L-Bsnd Radiometer - The S194 L-Bsnd Radiometer was a micr~ave radiometric sensor, utilizing a fixed planer array antenna, oriented toward Nadir. The system measured the earth's thermal radiation and provided a digital representation of 0 to 3S00 K input temperature range to an accuracy of 10 K, at a center frequency of 1.413 GHz. The antenna beam provided a non.inal 6Ox60 nautical mUe footprint coverage of the earth. The energy received by the antenna was integrated at a rate that ensured a minimum of 80 percent ground coverage overlap. The 5194 L-Band Radiometer consisted of the antenna, an electronics box and a mounting truss. (a) S194 L-Bsnd Radiometer Description - The 8194 L-Bsnd Radiometer was a modified Dicke type radiometer with gAin m~dulation utilizing a tuned radio frequency -eceiver. It had an integration time of ,.~ond and a band width of 27 MHz (1.400 to 1..-+Z7 GHz). The radio- meter measured the effective antenna tempera- ture by comparing it to a reference at a Dicke switch rate of lOS Hz. The electronics had a dynamic range of OOK to 3S00 K with an accuracy of '± 10 K. The system included two automatic calibration intervals; one cycle calibrated every four minutes and the other every 34 minutes. A manual calibration could be initiated by the crewmen from the EREP C&D panel. I 2-368 ) ~, The data output of the radiometer was a slowly vRrying DC voltage sampled at a rate not to exceed 200 :·1PS. The mounting truss supported both the antenna and the electronics box. It was designed to maintain the alignment requirements of the sensor and withs~and the MDA dynamic enviro- ments. (b) Functional Interface Descriptipn - Control for the S194 L-Band Radiometer was contained in the EREP C&D Panel and all scientific and hOllsekeeping data was routed from the sensor through the C&D Panel and recorded on the EREP Data Recording System. C. Test - The component tests were performed by the expedme!lt developer prior to being delivered as GFE. For details refer to the Experiment Final Program Repor';. For systems testing see section 7 of this report. D. Mission Results - All aspects of MDA and AM/MDA inter- face requirements affecting the EREP experiments were satisfac., torily met. Concerns that developed at the EREP system level were possible loss of Flight Time Reference System (TRS) in the AM and possible loss af AM coolant loop. The severe electrical power restrictions during the earliest part of the mission were successfully worked around. Results of individual experiments performance during the mission can be found in the Experiment Final Program Report. (1) S190A - Interfaces were satisfied. Concerns with malfunctioning lights, with "dust or bubbles" inside the lens assembly and, later, with slowing or inoperative shutter drive were internal to the experiment. (2) S191 - All interfaces were satisfied. A substan- tial concern that an 5191 door failure was eminent developed early in the mission and persisted until the operation was demonstrated to be complete, including proper latching. The first opening of the door, reported at 3 minutes (in contrast to nominal KSC test value of 1:45) was the basis of this concern; door operations were absolutely minimized throughout the mission in the belief that total failure might occur at any time. As a 2-369 result of leaving the door open or unlatched: • alignment could not be performed as had been scheduled • colder temperatures were presented to the Malaker cooler • longer warmup time was required. These matters were routinely handled by the MDA Mission Support!EREP Support Opera~ions. (3) S192 - MDA intetface requirements were met. Thu cooler-detector-preamplificr assembly (CDPA) was installed at the beginning of the first manned mission and the CDPA did not, it was later found, mate properly. This created considerable crew difficulties and confusion in alignment procedures and final readings. The second crew readjusted the CPDA and normal procedures worked and expected values were observed. A noise in the 18-20 Hz range was present in the flight an~ in the St. Louis test data as modulation on the expected data. It appeared that this noise was built into the experiment design. (4) S193 - Mechanical, electrical and operation~l interfaces with the orbital assembly and the EREP C&D Panel were satisfactory throughout the mission. The crew interface ·~ith S193 C&D Panel presented a more complex situation than usual as a r~sult of constraints on sequence and timing of S193 switches and sights. After the first operations by each crew, the problems were mastered and operations became routine. The gimbal system of S193 exhibited an abrupt failure during the SL-1!3 mission. A short in the power circuits to the gimbal systems rendered the pointing uncontrollable. A test··and-fix box was taken up on SL-4 and . sed during EVA. The existence of a short was confirmed and the box was used to open the circuit to the shott restoring the remaining functions employing the power system. The gimbal launch-lock pin was also installed locking the inoperative axis. The 8193 operations during the SL-l/4 mission were performed within this additional constraint. The mechanism which 2-370 L s could have caused the short was considered, and sper-ulation seemed to suggest that thermal blanket material may have moved into the gimbal pot near the high end (with respect to ground) of the electrical sensor winding around the structural member. (5) 5194 - Mechanical, electrical and operational interfaces with the orbital assembly and the EREP C&D Panel were satisfactory. The rare, unexpected operations of indicators were the result of out of tolerance temperatures or insufficient time to reach in-tolerance temperatures. E. Conclusions and Recommendations - All EREP interfaces with MDA hardware and subsystems were satisfactory. The crew interface at the EREP C&D panel was highly successful, confirming thls approach of a centralized nerve center for all the EREP expertments. Centralized power distribution, sensor control and data processing is highly recommended for future experiment operations of this nature. 2-371 / ,--,,--------- -----'1 'J 1 ~ ii 2.2.10.2 Materials Processing in Space Facility (NFF) A. Design Requirements - The Materials Procl'ssi.ng in Space Facility consisted primarily of a sphere lor vacuum envir<>nment, an electron beam source, and ass~ci .. ~"d mechanical and electrical hardware. The' facility was utiHzed for numerous experiments which were performed in the Zero-G anrl vacuum environment. The MDA/Experiment interlaces required for these experiments, and the correct environments were: (1) Mechanical - The MPF "as shock-mounted in the NDA, The entire facility was mounted on honeycomb panels and then in9talled in the MDA. The stowage con- tainer was mounted in th" same n;anner. (2) Electrical· The MPF requirlld only the 28 VDC interface fat, its operation, When the M518 Multi- purpose Electric Furnace (MEF) was added, it also required pO',ler from the hi-power utility outlet and telemet't"y data interface utilizing the Speaker Intercom Sys~em. (3) Vacuum- (a) The MDA provided a 4-inch line to the external vacuum environment. This line was controllable with two 4-inch valves placed in series between the MPF and the MDA bulkhead. (b) A Battery Vent Line was provided for overboard' dump of battery gas. (4) Water - The MDA was compatible with a flex line water hose from the OWS to provide quenching water for M479. (5) Vacuum Cleaner - Access around the MPF was necessary for using the vacuum cleaner attached to the vacuum cleaner port. B. Functional Objectives - The objective of the MPF was to provide a facility (see Figures 2.2.10-7 and -8) in which to demonstrate and evaluate the merit of performing various repair and assembly techniques and numerous procedures needed to process certain materials research projects in a Zero-G and vacuum envir~nment. Molten metal flow, freezing patterns, thermal 2-372 '- .~ Figure 2 .2.10-7 H512 Materials PrJ cessing in Space Facility Figure 2. 2 .10- 8 M~ 1 2 E1ui pmcnl St ow~ Re Con t ~in e r 2- 373 stirring, fusion across gaps and surface tension were examin.ed. The Experiment objectives were met by performing various experiment tasks within the facility. The following is a listing of the experiments and their objectives by number and title: (1) M479 Zero Gravity Flammability - Ignite various materials in Skylab cabin atmosphere to determine: • Extent of surface flame propagation, flashover to adjacent materials, etc. • Rates of surface and bulk flame propagation under ZCT~ convection. • Se If -e.'(tir.guishment. • Extinguishment by vacuum or water spray. (2) M55l Metals Melting - • Study behavior of molten metal in micro-gravity. • Establish means of materials joining and cutting in space, and maintenance of orbiting structures. (3) M552 Exothermic Brazing - • Study behavior of molten metal in reduced gravity (in particular, surface wetting and capillary flow) • To demonstrate a heat source fo~ melting metal in space. • To test and demonstrate a method of brazing components for space repaiI and maintenance operations. (4) M553 Sphere Forming - • To evaluate segregation in binary alloys and pure metal solidified in micro-gravity. • To determine amount of supercooling of a pure metal solidified in micro-gravity. • To determine the smoothness of metal surfaces solidified in micro-gravity. The M5l8 Multipurpose Electric Furnace (Figure 2.2.10-9) experiment system was approved for the Skylab Mission in June 1972 to provide necessary thermal parameters for the following experiments: 2-374 Figure 2.2.10- 0 MS18 Multipurpose Electric ~'~nace .... -,-.-,.,.------ (1) M556 Vapor Growth of IV-VI Compounds - To determine the degree of improvement that can be obtained in the perfection and chemical homogeneity of crystals grown by chemical vapor transport under weightless conditions. (2) M557 Immiscible Alloy Compositions - To determine the effec~s of near Zero-Gravity on the processing of material compositions which normally segregate on earth. Solidification of immiscible metal liquids under isothermal conditions with a third sample to be solidified in a temperature gradient. (3) M558 r~dioactive Tracer Diffusion - To measure self-diffusion and impurity diffusion effects in liquid metals in space flight and characterize the disturbing effects, if any, due to spacecraft acceleration. Specifically, determine the diffusion coefficient of radioactive zinc in natural zinc. (4) M559 Microsegregation in Germanium - To determine th~ degree of microsegregation of doping impurities in germanium caused by convectionless directional solidification under conditions of weightlessness. (5) M560 Growth of Spherical Crystals - To grow doped indium antimonide (InSb) crystals of high chemical homogeneity and 'structural perfection and study their resulting physical properties in comparison with theoretical values for ideal crystals. (6) M561 Whisker-Reinforced Composites - To produce void-free samples of silver reinforced with oriented silicon carbide whiskers. (7) M562 Indium Antimonide Crystals - To produce doped semiconductor crystals of high chemical homogeneity and structural perfection and to evaluate the influence of weightlessness in attaining these properties. (8) M563 Mixed III-V Crystal Growth - To determine how weightlessness affects directional solidifi- , cation of binary semiconductor alloys and, if single 2-376 . . crystals are obtained, .to determine how their semi- conducting properties depend on alloy composition. (9) M564 Halide Eutecticd - To produce highly continuous controlled structuces in samples of the fiber-like NaF-NaCl eutectics, and to measure their physical propertie s. (10) M565 Silver Grids Melted in Space - To determine how pore sizes and pore shapes change in porous structures when they are melted and resolidified in space. (11) M566 Aluminum - Copper Eutectic - To determine the effects of weightlessness on the solidification of Lamellar structure in an eutectic alloy when directionally solidified. C. Test - Component level tests were performed by the experiment developer prior to being delivered to the MDA as GFE. For details refer to the Corollary Experiments Final Technical Report, TMX-64809. MDA systems level testing results are included in Section 7 of this report • D. Mission Results - 8L-l/2 - Experiments 14551, M552, and M553 were performed as scheduled.· Slightly longer than anticipated times to achieve the desired working pressures in the chamber, and a malfunction in the cir- cuitry controlling the shutoff of the electron be~m were the only events marring the success- ful operation of the facility. The extended time to achl~ve the pressures impacted the number of samples cQmpleted on M553 (21 of the scheduled 28). The malfunction of the electron beam gun was successfully corrected through an oper~tional procedure using the battery circuit breaker to terminate the ·beam when necessary. SL-l/3 - The M5l8 series of experiments was scheduled to be performed on the SL-l/4 miSSion, but due to the availability of mission time and the crew's request for additional work, approval was granted by the Flight Management Team to perform as many of the M5l8 expeliments as .... ---.~ .. ------------- possible on SL-3. Thus, the entire series of eleven experiments (3 samples each) was performed. The system performed as designed with two exceptions, neither of which created a problem or was considered an anomaly. First, the heat-up times were generally shorter than expected. This was due to the AM Bus 1 voltage being slightly higher (but well within tolerance) than that used to predict the heat-up time. Second, there was an apparent" slip" in the "Soak Temp" potentiometer, resulting in slight variations in the furnace soak temperatures obtained. SL-l/4 - Seven of the M5l8 backup experiments were launched, performed, and returned successfully. The heat-up times were slightly longer than anticipated, again due to minor variations of the AM Bus 1 voltage. M479, "Zero-G FlamabUity" was performed as scheduled. All samples were performed, with the only Significant problem being the perfor- mance of the water quench system. The system did not operate as in~ended, but it could not be determined whether the problem was proce- dural, or a hardware malfunction. A more detailed discussion of the results obtained during the three manned mission can be obtained by referring to the Corollary Experiments Final Technical Report, TMX-64809. E. Conclusions and Recommendations - See the Corollary Experiments Finsl Technical Report, TMX-64809. I " r, ------- ,.i I. I' ; i I I j J i i i j. ", I I I I I f ) 2.2.10.3 SOO9 Nuclear Emulaion A. Design Requirements - MDA support to the SOO9 consisted of physical ~upport, a controlled environment and electrical power. The experiment consisted of a detector package, an experiment housing assembly and the support structure furnished by the experiment developer, the Naval Research Laboratory (NRL). The detector package wae launched in the OWS film vault and transferred on orbit to the experiment housing which was per- manently mounted in the MDA. The support consiated of two besms attached between two longerons in the forward section of the MDA. This aligned the experiment housing such that the detector pointed along the -y axis. The skin of the MDA, between these two longerons, was then chem-milled to 0.076" from a nominal thickness of 0.250", to allow a uniform skin as thin as possible to "look" through. The MDA provided the controlled environment required by the detector package emulsion and 28 VDC at a maKim~m of 1.25 amps. Further details concerning the design requirements and. interface requirements can be found in the Experiment Require- ment. Document (SE-010-022-2H) and the appropriate leDS: • Mechanical l3M12l9l • Electrical - 4OM35652 B. Functional Description - The objective of the experiment was to study the charge spectrum of primary cosmic rays, obtain detailed chemical composition of the heavy primary nuclei, search for rare particles, and study these phenomena aa a function of the solar cycle. This w~s accompliahed by exposing a stack of layers of emulsion and studying the tracks left by the cosmic rays as they passed through. Two actions were taken to eliminate unwanted particle tracks such as protons in the South Atlantic Anomaly. First, the detector package containing the emulsion was hinged along one edge much like an open book. This allowed the package to be closed or put in a "data reject" mode. Thus, any track that could be traced across the interface between the two halves could be considered to have occurred during the data reject mode and wal not analyzed. Second, the detector package was oriented so that it "looked" eaaentlally perpendicular to the orbit plane. This wal to eliminate secondary particle tracks resulting from collisions between the primary cosmic rays and the earth's atmosphere. 2-379 ···········-r·· 1 ! I ! I I I I I I I • These two functions were accomplished by the detector housing assembly mounted to the wall of the MDA (see Figure 2.2.10-10). The opening and closing of the package was con- trolled by a stepping motor activated through a timing circuit. The period of the orbit was set, then the fixed open snd closing cycle insured that the package was closed whenever the OA was north of 30 degrees north latitude or south of 25 degrees south latitude. Orienting the package perpendicular to the orbital plane was accomplished by the astronaut. His participation was required because the pointing of the experiment varied with the beta angle of the orbit. Thus, he was required to make an ad- justment to the experiment pointing anywhere from once a day to once every six days, depending on what part of the beta angle versus time curve the mission covered. C. Teat - Component tests were performed by NRL prior to being delivered as GFE. For details refer to the Corollary Experiments Final Technical Report, TMX-64809. MDA systems level testing is included in Section 7 of this report. D. Mission Results - The 8009 Nuclear Emulsion Detector Package was transferred from the OWS Film Vault on MD5 (toy 149) of SL-2 and was successfully deployed, although the crewman commented at the time that the package was very difficult to install because of tighter-than-expected tolerances between the package and the Experiment Housing. The package was exposed for 21 days, and then on MD26 (DOY 170) it was removed on schedule from the experiment housing and stowed in the CM for return. The experiment did not perform as well ss expected, and the data was degraded due to: (1) High temperatures in the OWS Film Vault during the first 13 days of SL-l. (2) Late deployment due to the delay of the lsunch of SL-2. (3) The tendency of the package to stall on the cycle of the automatic open/close sequence. problem was noted on MD17 (DOY 161). close This The first two of these problems were related to the loss of the OWS meteoroid shield with the resultant high temperatures and late scheduling of the SL-2 launch. The OWS temperatures climbed far above nominal and remained there for several days. The Nuclear Emulsion Package reSided in Drawer J of the OWS Film Vault during this period. Although there was no temperature 2-380 I .-, Figure 2.2.10-10 S009 Nuclear Emulsion 2- 381 sensor in the FiUn Vault, the temperature could be closely estimated by use of the sensors in the vicinity of the vault. The temperature was above 90oF, the nominal maximum, from DOY 136 to DOY 149. From DOY 142 to DOY 147, the temperatures were between l200 F to l2SoF. These extremely high temperatures led to the softening and sticking together of the individual layers of the emulsion to such an extent that they were deformed when separated for analysis. In addition, the background fogging level increased by a factor of 2. Late deployment was deleterious because the Nuclear Emul- sion Package begins to gether data (cosmic ray tracks) from the day the film is made until the time it is processed. In spsce, of course, the effect is much greater since there is no shield- ing atmosphere. Therefore, the additional ten days that the package spent in orb1t in a data reject mode (package closed) added to the background "noise" that had to be eliminated during the postmission analysiS. Or MD17, the motor/drive train proved incapable of closing the Emulsion Package. This condition interrupted the timing sequence of the package openings and closings that were accurate- ly synchronized with 300 north and 2So south latitude crossings. -The decision was made to turn off the motor and deploy the Emulsion Package open, but with the continued manual pointing updates. This mode of operation continued through MD26. In order to evaluate the motor/drive train condition, a set of questions were uplinked to the crew and later a malfunc- tion procedure was prepared in a coordinated effort with NRL, JSC and MSFC. The procedure called for the cycling of the motor/drive train through several opening/closing sequences without a package present, but with the crewman actuating limit switches manually. When tried by the crew, the motor closed the emulsion package with some hesitation at the midway point. It then opened, but when the attempt was made to close it again, it stalled. A backup package was prepared for launch on SL-2, but was not launched due to limited CM stowage. It was then approved to be launched on SL-3, but was again deleted due to stowage considerations. It was launched and performed on SL-4. A replacement motor assembly was launched on SL-3 to replace the degraded unit on orbit. Inflight maintenance was performed prior to the activation of the experiment on SL-4. 2-382 ) E. Conclusions and Recommendations - 8kylab experience has shawn the importance of supplementing Telemetry over and above information gathered through voice contact with the crew. The anomalous condition of 8009 could have been discovered at· its first occurrence and possibly converted had telemetry been provided to indicate when the motor was operating. This also would have allowed the ground support personnel to relieve some of the duties of the crew, such as requiring them to adjust the experiment only when required, rather than on a regularly scheduled basis. Testing of the experiment could have included zero-G simulation. This would have allowed investigation of the effects of the high mass of the detector package on the open and close cycle. It also would have provided an evaluation of the adequacy of the motor to perform this function. Overload protection on the motor itself might have detected those times when it is predicted that the package stalled. 2-383 I .. -.. ~, --------------- • , 2.2.10.4 Proton Spectrom~ter A. Design Requirements - The Proton Spectrometer required support from the MM it. the form of physical support, electrical power, and instrumentation and communication. Specifically, the instrument was mounted to the L-band truss (see Fi§ure 2.2.10-11) such that the detector had a clear field of view (a 45 acceptance cone) along the Y axis. The instrument was, in addition, bonded to the structure through the truss. Electrically, the MM provided 28 VDC at 5.9 watts maximum load. The I&C interface accommoda ted: I Figure 2.2.10-11 Proton Spectrometer Installation 2-384 , I , ~ " I f, I'! rl b rl ~ r: Ii tl ~: l' i f I' , ~ ! 1'1 \ , , I I I \ • A 6 VDC count/calibrate threshold change signal. • Detector head, and electronics temperature measurements. • Trsns~ission of a l2-bit digital word. • Two particle rate counting measurements. • A spacecraft clock signal for data synchronization. Further i,nformatf.on can be found in the Instrument Require- ments Documel',c for the Proton Spectrometer (Repository No. SE-010-050-2H), or the applicable ICDs. • Mechanical - l3M135l3 • Electrical - 4OM35664 • I&c - 5OM16134 B. Functiol1a1 Description - The objective of tlle experiment was to determf.ne the energy spectrum and intensity, as well as the pitch angle distribution, of electrons and protons trapped in the radiation balts of the South Atlantic Anomaly. Time variations of thece measurements over long periods should help in the analysis of: solar modulation of the radiation belts. Solar flare radiation was also recorded. This knowledge of the energy spectrum of the particles should aid in the design of shielding, the choice of films and film developing procedures, and the determination of radiation dosage being received by the crew. The Proton Spectrometer was a charged particle spectro- meter mounted on the L-band truss external to the MDA. It measured electrons from 1.2 to 10 MEV and protons from 20 to 400 MEV. The spectrometer consisted of a detector head, and electronics housed in a single instrument. The detector head was a particle-identifying and measuring device (see Figure 2.2.10-12). It measured specific energy loss in two thin 801id state detectors and energy in a cesium iodide crystal detector. These three detectors were surrounded by a fourth detector, a plastic scintillator. which operated in anti-coincidence. The scintillation counters were viewed by photomultiplier tubes. When in the South Atlantic Anomaly, the intense electron radiation environment resulted in a very high counting rate in the individual detectors despite heavy shielding. Therefore, very fast electronics were used and multiple coincidences and anti-coincidences were required before a particle was counted. 2-385 , . " , ''l. ----,--'" N I ~ '" D2 I'REAWLIFIER 01 "'EAMPLIFIER SOLID STATE DETECTORS ANTISCATTEIUNG IYSTEM HIGH VOlTAGE POWERS~IES CESIUM IODIDE CRYSTAL RF COMMAND BOX -Figure 2.2 . 10-12 Proton Spectrometer Detect9r Head Assaably r ;, i P l- i , f~ Ii II t , t I , I I ; 1 I I , The instrument was normally acquiring calibration data, using an alpha source grown into a cesium iodide crystal as a reference. Both scintillation detectors sensed the radiation environmentcontinuoua1y. One ac1~ti11ation detector signal was sent to a threshold discriminator. The discriminator was used by the control logic to bring the detector system into its counting mode automatically. This method of automatic count-ca:ibrate mode changes re.uir~d initial knowledge of radiation to be measured in order to properly set the reference threshold voltage for the diacri- ulinator. Therefore, a ground conunand was used to change this reference voltage, as well as providing a ground command capa- bility for turning the instrument on or off. The status of the reference voltage was changed in steps by repetition of the ground commands. The Proton Spectrometer, due to the layout of the coinci- dence and anti-coincidence detectors, had an acceptance cone angle of 450 from both the front and rear of the instrument. Knowledge of the orientation of the OA while passing through the South Atlantic Anomaly Yielded information ebout the pitch angle distribution of the spiraling particles. The output of the instrument consisted of two analog temperature measurements, two analog count measurements (indic~ting the total flux of the radiation field) and a l2-bit digital word. The digital output was updated at a 10 per second rate and provided the complete data frame of 12 words in 1.2 seconds. The complete data output per orbit was reconstructed aftel' the orbit. Real time data recorded by the ground stations was combined with AM recorder dump data covering periods when no ground coverage existed. Real time monitoring was limited to the four analog measurements. Near real time monitoring could be accomplished by addressing the mission data retrieval system via MOPS. C. Test - Component level tests were performed by the Experiment Developer prior to delivery as GFE. Details of these tests are contained in the Corollary Experiment Final Techn£ca1 Report, TMX-64809. MDA systems level testing is discussed in Section 7 of this report. 2-387 i "" D. Mission Results - The instrument was scheduled to be turned on appI~ximstely five hours after the lsunch of SL-1 by ground command. The activity caused by the loss of the meteoroid shield delayed instrument activation until approximately twelve hours after launch. By this time, the temperature of the instrument had dropped to _23 0 F. The design condition low temperature wss +14°F. Data output uuring this period indicated that the instrument was not calibrating itself. Efforts were then undertaken to lower the OWS temperatures by taking the cluster out of the Bolar inertial orientation, basically pitching the X-axis toward the sun. This resulted in some radiant heat input to the instrument, and the tempera- ture increased to approximately +40~ and stabilized there for the next eight days. The data during this ·period indicated some improvement in instrument performance. The third period of the instruments thermal history occurred with the assumption of solar inertial attitude (returning the Proton Spectrometer to the shade) and tbe hard dock of the CSM. The temReratures were within ±5~ of -25~ for the detector head and -15iF for the electronics. The result of this lower than predicted thermal environment is discussed in HOSC Action Request AR-444, and a Failure Analysis Report prepared by the experiment manager, George Detko, S&E-SSL-S. Briefly, the internal gain of the instrument dropped so low that it could not calibrate itself, rendering only two of the thirteen data channels UGGful. All of the proton channels and two of the three electron channels were lost. The remaining data consisted of on~ channel of low energy electrons and one channel indicating the total flux of the field through which the instrument was passing. The lower internal temperature resulted due to a design error concerning the value used for the emissivity of the inner face of the thermal shroud. An emissivity 0.05 was used rather than the actual value of 0.88. Thus the instrument did not retain as much of its internally generated heat (both from the electronics and two small heaters) as was predicted. The low temperature was predicted.to have caused a mechanical failure within the detector head. Specifically, the scintillation detectors (protons or electrons striking them create small flashes of light - scintillation) were· light coupled to a pholo- multiplier tube by RrV 615. The coefficient of thermal expatlsion 2-388 \' I' !\ Ii I: I' I' 11 'I " i , " , , i I I , L \ and contraction was believed to be responsible for a gap at the interface either between the detector and the RTV or the RTV and the photomultiplier tube. Either way the end result would be an effective loss of gain in the instrument. Thus, the instrument was incapable of determining the energy levels of the electrons or protons. The failure could poss1.b1y have been reversed by raising the temperature of the detector head to bring the RTV into contact with the surface. It was proposed to install a thermal blanket to accomplish this, but due to the complexity of in- stalll.ng it on orbit and limited launch stowage, the effort was tern.lillated. The Proton Spectrometer continued to transmit the two useful channels of data throughout the Sky lab missions. E. Conclusions and Recommendations - It is likely that had the Proton Spectrometer been subjected to a thermal vacuum test, the error in the thermal shroud emissivity value ,~ou1d have been detected and corrected. Although one was planned, a failure of the qual unit prior to the thermal vacuum test necessitated qualification ~y analysis. Schedules for the development of space hardware should include adequate time to allow a failed unit in test to be analyzed and all scheduled testing completed. 2-389 2.2.1 0 . 5 So l a r Radi o No i se Bur s t ~l o nit 0 r (RNBH) A. De si gn Requir eme nt s - 1he ATN So lar Radi o No ise Burst Monit or re ce ive rs we r e mounte d on a n !-lOA pane l ab ov e the ATM C&D pane l ( see F i gure 2 . 2 . 10 -13 ) . The tw o identical units were mounte d s uc h that th e two ca bl es ( one ant e nna , and one power and signal) c ou ld b. connected t o e ithe r uoit. the flight o r spare. I 1', It. ' . 1 Figure 2.2 .10 - 13 Solar Radio Noi s e Burst Nonitor Installation 2-390 I I , The MDA, in addition to physically supporting the receivers, provided approximately 1.4 amps of 28 VDC power,. and a signal interface with the ATM C&D console for an analog output to a history plotter and a discrete to an alarm. B. Functional Description - The ATM Solar Radio Noise Burst Monitor system received solar electromagnetic radiation in the 5 GHZ frequency range, and indicated the absolute intensity of this radiation relative to an internal noise source calibration. The system consisted of a two-foot diameter parabolic antenna mounted on the AM truss, and a receiver mounted in the MDA, connected with low loss coax cable. The operation of the system was based upon the detection of an increase of approxi- mately 5 solar flux units (SFU) to accompany most significant solar events. The receiver accepted the signal from the antenna and displayed its intensity on a 0-5 volt meter on the face of the instrument. In addition, it presented an analog signal to a history plotter on the ATM C&D console and, when the intensity exceeded a threshold set by the astronaut (which corresponded to the ambient solar radio noise), it delivered a 28 volt DC signal to an alarm circuit. The receiver had a built-in calibration noise source and a mode switch that allowed the selection of either the antenna or this cal source. A system gain adjustment and balance adjustment was provided to allow calibration relative to this n01se source. It also contained an internal clock that allowed the pariod of the orbit and the "on time" to be set. Thus, the instrument could be adjusted to be activated only when the cluster was in the view of the sun. C. Test - The component level tests were performed by the experiment developer prior to being delivered as GFE. For details refer to the Corollary Experiment Final Technical Report, TMX-64809. For systems level testing, see Section 7 of this report. D. Mission Results - The RNBM was activated at approximately 16:40 on DOY 163. The activation occurred later in the mission than scheduled due to power conservation efforts in the early phases of the misSion. Dr. Kerwin reported that "it cal~brated very nicely." 2-391 r ,\ \j I , I As the mission progressed, it was reported that the paper had jammed in the history plotter and could not be repaired. It was also noted that the threshold setting was fsirly critical to preclude false alarms at sunrise and sunset. Since the calibrated signal to the history plotter was no longer required, the Principle Investigator, Dr. Owen Garriott, revised the sensitivity adjustment to mBximum. On SL-3 Dr. Garriott utilized this same calibration system. In the crew debriefing he reported that the RNBM was a useful tool as a backup to the X-ray sensors as an early indicator of solar flare activity. E. Conclusions and Recommendations - Refer to the Corol- lary Experiments Final Technical Report, TMX-64809. 2-392 . \ I I I , ') ; a t ~ 2.2.10.6 ATM Control and Display Subsystem A. Design Requirements - (1) The ATM Console supplied the necessary controls and displays for conducting the following experiments. • High Altitude Observatory (HAO) White Light Coronagraph (WLC) Experiment • American Science and Engineering (AS&E) X-Ray Spectroheliograph Experiment • Naval Research Laboratory (NRL) Extreme Ultra- violet (XUV) Coronal Spectroheliograph and Spectrograph Experiments • Harvard College Observatory (HCO) Ultraviolet (UV) Scanning Spectrometer Experiment • Goddard Space Flight Center (GSFC) X-Ray Telescope to Hydrogen-Alpha (H OC ) Filter Experiments , (2) Controls and displays were also provided for moni- toring and/or operating the ATM Attitude and Point- ing Control System (APeS), Power Supply System, Lighting System, Telemetry System, Computer System, Experiments Closed-Circuit Television (TV) System, Canister Thermal System, Event Timer and Alert Subsystem. A cooling system was provided to con- trol the console thermal characteristics. (3) The overall Console dimensions were in accordance with 4007870. (4) The console weight was limited to the value speci- fied on 4OM37870 (630 lb max.) (5) Thermal cooling of electrical components was ac- complished through the use of active (liquid) cooling. The coolant was circulated through cool- ing lines attached to structural members in those areas of the Console that were thermally critical. (6) The console colors were in accordance with 4OM37871. (7) Inverter/Lighting Control Assembly (I/LCA) - The I/LCA provided regulated and unregulated electrical power, both alternating current and direct current, to the ATM C&D Console. The I/LCA used electrical power provided by ATM busses. (8) Backup Inverter/Lighting Control Assembly (BI/LCA) - The BI/LCA provided fixed and variable AC backup powe,~ and fixed DC backup power to the A'l'M C&D Console in the event of failure of the primary power source, the I/LCA. (9) Digital Address System (~S) Backup Device - Expansion of console ~S requirements to provide functions addressable only by the ~S keyboard necessitated the addition of a backup capability. The functions provided by the console ~S keyboard and the ~S Backup Device included the fol10wing: (a) Backup capability for control of critical subsystem functions. ~b) Control of critical functions addressable only by the ~S to the A'l'M Digital Computer, e.g., command vehicle attitude change, command TACS pulse Width, etc. (c) Capability for power malfunction isolation of the A'l'M subsystems, e.g., AS&E main power ON, AS&E main power bus no. 1 OFF, AS&E main power bus no. 2 OFF. The AS&E main power ON-OFF switch did not provide the capability for removing a single power bus. (d) Subsystem operational flexibility, e.g., the telemetry subsystem was provided with approxi- mately 125 commands through the ~S. (e) Commands to display APCS parametric information. (l0) EVA Rotation Control Panel (ReP) - The A'l'M EVA RCP enabled an astronaut to control the rotation of the canister to gain access to the camera doors for film loading and removal. Rotation of the RCP handle in the left or right direction caused canister rotation in the respective direction. The ReP consisted of a housing, control handle with appropriate mechanical assembly, and electrical equipment. The unit conformed to Drawing 4OM37795. 2-394 , \ 1 I The RCP also supplied ,witching fo r r e dundant panel input powe r, r oll contr o l activation, and S082 doors c ontro l. A separate visual pos iti on-status display f o r each of the two S082 d oors was provided. B. Functi onal Description - Th e Control and Display Sub- system, consisting of the C&D Console, the I/LCA, the BI/LCA, the !lAS Backup Device, and the RCP provided th e crew interface for the operation and management o f the ATH exper iments and subsystems. This interface wa s provid e d primarily by the C&D Console on which the controls and ,lisp lays requi r e d t o operate the ATM experiments and subsystems (see Figure 2 . 2 .10-14) were located. Commands were pr ovided t o the ATH by t ogg le and rotary switches, the Hanual Pointin g Controller and the !lAS. Monit oring Fi gure 2.2.10-14 ATH C&D Conso l e 2-395 was accomplished by the ~se of status lights and flags, alert lights, dual scale vertical meters, pulse counters, digital displays, an activity history plotter, and TV displays. Addi- tionally, the C&D Console interfaced with the MDA RNBM, providing data recording and monitoring capabilities, and interfaced with the OWS Thruster Attitude Conty"l Subsystem (TACS), providing status monitoring and thruster inhibi.t command capabilities. All critical command and display functions were implemented through redundant wiring and switching contacts, alternate displays, or were available through the ~S. A summary description of the major C&D subsystem components is provided in the following paragraphs: (1) ATM Control and Display Console - The C&D Console contained all components required for commanding and monitoring the following ATM experiments and subsystems. (a) Experiments • Hydrogen-Alpha (H",,) 1 and 2 Telescopes • X-Ray Telescope (S056) • XUV Spectroheliograph (S082A) • White Light Coronagraph (S052) • UV·Scanning Polychromator Spectroheliometer ( S055A) • ~-Ray Spectrographic Telescope (S054) ( b) Subsys terns • Attitude and Pointing Control System (APCS) • Telemetry (TLM) • Power System • TV System • Canister Thermal • Ground IDAS • Alert C&D components were arranged on nine panel assem- blies, each removable fnr servicing during ground checkout operations, The experiment controls and displays were centrally located in a row-column matrix configuration wherein rows contained experiment controls and displays and columns contained controls and displays having a common function. Subsystem controls and displays were functionally grouped around the periphery area. 2-396 r , j ! I I ) Time sequenced controls ran from left to right within each experiment and subsystem grouping. A History Event Recorder, located in the lower left-hand corner of the console, provided an onboard record of solar activity. The device provided for simultaneous recording of two channels of analog data. One channel recorded the X-Ray Telescope (S056) X-Ray Event Analyzer (X-REA) outputs; the other channel recorded RF activity as provided by the Solar Radio Noise Burst Monitor. The controls and displays for the Attitude Control System provided for activation and mode selection of the Experiment Pointing Control System, Star Tracker, and momentum dump. They also provided override controls for the CMG subsystem and the ATMDC, TACS inhibit commands and thrus~er stat~s, and Fine Sun Sensor experiment bias enter contruls. The Manual Pointing Controller (MPC) allowed manual control of the Experiment Pointing System and the Star Tracker. The MPC could be replaced in orbit with a spare provided onboard. (MDA Misc. Stowage Container, MlS7) The controls and displays for the telemetry system provided for activation of the system and mode control. Mode control allowed the activation of the ATM tape recorders in the record or playback mode, the selection of tape recor.der or real time inputs to the ATM transmitters, and the selection of forward or aft antennas for each transmitter. The power system displays provided status monitors fc.: the individual ATM CBRMs, status flags which cued the operator to off-nominal conciitions, and dual scale vertical meters to monitor parameters of the ATM main busses and individual CBRMs. The TV controls provided for the activation of the ATM TV system and f6r the operation of the individual ,experiment TV cameras. Two TV moni~urs were provided, each of which displayed any of five TV Signals from ATM experiments; Ho<. -1, He)(. -2, XUV MON, WLC and XUV S11 t. 2-397 The canister thermal controls allowed selection of PRlMARY/OPF/SECON~RY pumps and controllers and heater pow~r AUTO/OFF. A dual scale vertical meter was provided for display of system parameters. The Digital Address System (~S) keyboard provided the command and data entry capability for functions which were not allocated a dedicated control and provided the backup command capability for control of critical subsystem functions. The alert advisory indicators warned the astronauts of a low level malfunction of an ATM experiment or subsystem. The system was independent of the Cluster Caution and Warning System and the functions monitored did not require immediate crew attention. The location within the console of major C&D components required direct structure mounting. A distributor assembly, located at the bottom of the console accommodated interpanel and subassembly wiring. All panel connections were routed directly to the distributor or interface connectors by means of an interconnecting harness, thereby eliminating inter-panel connector interfaces. Power distribu- tion, signal conditioning and relay switching required by the panels was prOVided by the distri- butor. Power was provided to the console by redundant main ATM load busses. Circuit breakers, located on the console power distribution panel, provided current overload protection. The use of p~wer distribution switches and/or circuit breakers provided a flexible power distribution scheme, therefore, console single point failures were capable of being isolated to insure against the loss of parts of \l1ore than olle experiment or the loss of an entire experiment or subsystem. Electroluminescent Lighting (EL) was utilized for • panel nomenclature, integrally illuminated dis- plays, and for numeric readouts. The numeric displays utilized green 'EL lamps which contrasted with the immediate background when energized. 2-398 I ! , I ~ I The lamps were designed for an operating life expectancy of 2000 hours, with end of light brightness defined as 0.2 foot-Iamberts for integral and 1.8 foot- lamberts for numeric lighting. Vibration isolation of the entire console was used to protect components from the severe dynamic environments of the MDa. A four-point, vibration- isolation, mounting scheme was used with the console CG in the plane of the isolators and equidistant to the isolators in that plane. Thermal control was provided by a liquid coolant loop which used an open cycle cold rail, fluid supplied externally by the AM coolant system. The console structure (frame) served as an inter- mediate heat sink, transferring component heat loads to the cool.ant loop for removal from the console. Inverter/Lighting Control Assembly - The I/LCA provided regulated and unregulated electrical power, both alternating current and direct current, to the ATM C&D Console. These various types of power were required for the operation of the console display components and the electrolumi- nescent lighting of the console nomenclature and display components. • Operational power was provided to the unit by ATM power busses with input and output circuit breakers located on the ATM C&D Panel. • A Pulse Width Modulator was used to satisfy the requirements of variable output and high efficiency for four AC outputs. Regulated DC outputs were generated from a ripple regulator type preregulator that prOVided the power to three separate regulator circuits. • The I/LCA thermal control was accomplished by a combination of active heaters, selected case finish, and thermal isolators. • The I/LCA was located externally on the forward conical section of the MDA and mounted on the L-band antenna truss. 2_399 (3) Backup Inverter/Lighting Control Assembly - The BI/LCA consisted of two DC to AC inverters, tw" auto-transformers, two 5 volt DC to DC converters, and a connector patch panel uaed in transferring the C&D Panel from I/LCA to BI/LCA. The BI/LCA system, in the primary mode of operation, provided a fixed and variable AC power by using one inverter and the two auto-transformerl. In the aecondary mode the BI/LCA provided only fixed AC power from the other (secondary) inverter. A fixed 5 VDC was supplied to the C&D Panel in both the primary and secondary modes by employing one of the two DC to DC convert~rs. The BI/LCA components were installed in the MDA aa illustrated in Figure 2.2.10-15. Inverter ,J.... (Ref.) ATM C&D Conwle - ... , ""- Ref.) Frame Sta 3522. S03 ~-(Ref.) cable Tray ----Converter Autotran sformer Assembly ~_--I nverter ,...t------{.onvert~r Figura 2.2.10-15 BI/LCA Inatallation 2-400 i I f I I (4) DAs Backup Device - The DAS Backup Device was installed in the MDA, adjacent to the right of the console, to provide command redundancy. This was a manual switching unit which utilized five rotary swit~hes tn format each command. Unlike the Console DAS, teedback from ATM was not avail- able to verify conunand transmission. lhe positions of the rotary switches were the only l~dications to the crew of the command transmitted. (5) EVA Rotation Control Panel - The EVA Rotation Control Panel was located at the ATM Center Work- station. It was used to rotate or roll the ATM experiment canister to any desired position within a range of ± 120 degrees from a mechanical zero roll reference position. During EVA it served as a control panel to position the ATM experiment canister such that each of the four film retrievall replacement doors (S052, S054, S056 and H-ALPIIA) of the ATM could be aligned with the Center Work- station and ATM experiment film camera assemblies could be replaced. Full rotation control capability existed at the Control and Display Console and provided a backup to the ReP. Thus, should the RCP control handle become completely disabled, ATM film retrieval could be accomplished by controlling canister rotation from the console under the direction of the EVA astronaut. C. Test - Component level tests were performed by the console developer prior to being delivered to the MDA as GFE. Refer to the ATM Final Technical Report, TMX-648ll, for systems level testing results. D. Mission results and recommendations are !.ncluded in the ATM Final Technical.Report, TMX-648ll. 2-401 1/ This Page Intent~onally Left Blank ( 2-402 ~. !', j! , 'I ) 2.2.11 Ground Support Equipment (GSE) The GSE described in this section is limited to those equipments provided by the Martin Marietta Corporation as Contractor Furnished Equipment (CFE) under the MDA contract. A more detailed description of each specific CFE end item accompanied by a hrief descript Lon of MDA related GFP GSE can be found in the MDA GSE Description Document, ED-2002-2002. 2.2.11.1 Structural The Ground Support Equipment (GSE) described herein was provided by the Martin Marietta Corporation under the Y~A contract. Structural GSE for the MDA flight article evolved from just five items in the orig- inal MDA proposal to a total of 83. The initial items were: one handl- ing fixture and sling; one transportation fixture; two access platforms; and one package handling kit. A hoist and track, two docking port pro- tective covers, and an STS sealing plate were supplied as GFP with the MM. As program requirements were defined, it hecame necessary to modify the GFP items.' The hoist and track, being supported inside the conical end of the MDA, was relocated to clear dome installations and its capac- ity was upgraded to lift heavier ohjects. The docking port covers were provided with adapters for use with the desiccant hreathers a~d the in- ternal heaters which were used during transportation of the MDA. The STS sealing plate, initially intended as a "losure during pressurization and leak testing of the MDA, was modified to accept a support adapter during transportation, rotation, and trunnioning of the MDA. Additional program directives identified structural GSE for instal- lation and removal of EREP, VTR, I/L~ and M5l2, protection of sensitive areas and equipment, contingency activities, and MDA test peculiar re- quirements • . In addition to providing for handling and transportation of the MDA and access inside the MDA, structural GSE was frequently used to perform special functions, and was designed specifically for unique activities and tasks. Some notahle ones were: • Support equipment used during horizontal rotation qf the }IDA and during weight and center-of-gravity determination of the MDA. • Hoisting and handling equipment (with the MDA in the hor- izontal attitude) used for contingency installation of EREP, Video Tape Recorder, I/L~ the M512, and the L-Band truss and antenna. 200403 • Crew support equipment inside the MDA during the altitud" chamber test. • Crew ffilpport, access, and ingrps~ equipm~nt used inside thp MDA during the inverted docking test. A. Horizontal and Verti.cal Handling (1) Design Requirem('nts - The handUng fixture was dehil-\n<'t' as a very rigid frame for lifting anJ transportation. A lifting load factor of 2.0 was used for design, wi.th mater!.al safety factors of 3.0 on yield and 4.0 on ult- imate stress. In order to prevent transmisRion of hend- ing moments or externally induced forces into the MDA structure, spherical sockets Were incorporated into the support legs of the fixture to mate with special lifting fittings on the MDA. The assembly was also designed as the MDA forward sup- port during transportation and rotation of the MDA, and during inverting of the AM/MDA. See Figure 2.2.11-1. Since the most critical loading conditions occurred dur- ing transportation of the MDA, the handling fixture de- sign was also based on the load factors defined in the General Specification for Air Transportation, NIL-'\-8!,21B and Aero Space Lines Cargo Loading Schedules ASL-30 and ASL-4n. The design requirement for the stronghack beam us;>d with the handling fixture was to support the outfitted MilA during hoisting and provide a co-planar MDA interface 14hen mating to the AM. Due to limited headroom at the MDAC-E facility, the beam was designed for use without slings or spreaders. See Figure 2.2.11-2. The lifting fixture was also required to support the mated AM/MDA during trunnioning and hoisting and to provide a true co-planar interface when stacking the AM/MDA onto the FAS. See Figure 2.2.11-3. (2) Description - Hoisting and handling of the MDA was as- sisted "ith the use of the Handling Fixture and Sling Assembly. The assembly consisted of three major com- ponents; i.e., a handling fixture that was secured to special fittings on the conical end of the MDA; a strong- back beam for mating the MDA to the AM; and a litting fixture for stacking the mated AM/MDA to the FAS. 2-404 ( , Thl' f unction pf t he handl ing fLxlure \,'aR t o d istrihut e tile Iwislin ).!. , handlin g , 3nd t ran s portation l oad s t hrongh fnur f i ll i ngR on t i l(' NDA and prnv i de- tlH' fo rwarcl Slip· porl fn r the HIM du r i ng t rnn spnrt:1tion o r ho ri zontal l"ntal i 0 11. and \.;hen tl"unn i o ni ng th e ~mA o r tiJ C' mated AN / NIlA tll the vc,) ' tical or hnrizontal at't:tud('~, and du rin}, inVl' l' t' ing of til(' A~I/NJ)A. 2- 405 .. Figure 2 . 2.ll - 2 HDA Trulln iu ned t o ll u rl z ullt.IL Attitude after ~1.: l t lll g t o AN The function of the s tro n ghack beam o r the lifting fixture was to f:upply tlte conne cting link hetween the handling fixture and th e ho isting facility during hoistin g of the NDA or the AN /~IDA. (3) Design/Test Verification - Durin~ thc ma'lu facture, and upon completion o f t he assemhl y , the tlnit .~ were examined to veri [ y con formance of t l1 C product to tllC eng i nee r i ng drawing s with respect t o mat e rials, di- me nsions, construction , i denti fication, and inte rrace r cquirements. 2-406 " Figure 2 . 2. 11-) AN / ND1\ TI'LLlllli u l1('d t~l V .. ' rti ..... 11 AtLitlld ... · fur St;h.: king l~, FAS Proof l oael t e stin g of the assemhl y \vas condu cted hy stati cally loadillA the ar.semhl y t o 200 p(,l'ccnt o f its clcsi ~n l oads. \vith no evidence of fail\1re o r dcfo rm- a t ion. Fit checkin~ of th e fixture to the r-tDA "'as not pos - sihlc prior to delivery a ne! f irst lise of tilt" product . ( 4 ) Prog r .ln! Us .lge - First lIsa ~(' of til .... 11 :111(11 ing Fixture .lIld SLtng Asscmh L\' was m:lde a t NSFC. TIt,- l1 nits '-I\"1" e Delivere d t o NSFC fo r fi.t cli .... ck il1 ~ . mal,.' h dri II ing of 2- 407 .... the fixture, and mating tc the MDA. The fixture was used for initial handling and loading of the MDA in preparatiun for shipment to the Martin Marietta facil- ities at Denver. The assembly was used repeatedly during handling, as the forward support during trans- portation, and during mating of the MDA to the AM. The versatility of the handling fixture was demon- strated in its varied uses. In Denver, the fixture wss adapted to the rotation fixture, as shown in Figure 2.2.ll~1. At St. Louis and KSC, the fixture was used in conjunction with associate contractor GSE for trunnioning the AM/MDA during inverted docking and stacking of the AM/MDA. Since a prior fit check had not been possible, high confidence was placed on previously verified ~nterface examinations. Also used successfully on a fir·st-time basis for rroviding co-planar interfaces were the strongback beam for mating the MDA to the AM, and the lifting fixture for stacking the AM/MDA to the FAS. (5) Conclusions -The Handling Fixture snd Sling Assembly encountered no significsnt problems in the design, build, or use. The assembly met and satisfied the design, functional, and interface requirements imposed by the Skylab program. The GSE performed as planned in all 'its uses and proved to be a highly reliable and safe set of handling equipment. B. Transportation (1) Design Requirements - The florizontal Transportation Fixture was designed as a rigid support cradle for the MDA during air and ground transportation. The fixture was designed to prevent external forces from being induced into the MDA. The design loading cri" teria were contained in the General Specification for Air Transportation, HIL-A-842lB and Aero Space Lines Cargo Loading Schedules ASL-30 and ASL-46. Material factors of 2.0 on yield stress and 3.0 on ultimate stress were used. The assembly was designed to distribute the transpor- tation loads to an aircraft pallet or to a flat bed trailer. 2-408 , (2) Description - Transportation of the MDA was accom- plished on t he Horizontal Transportation Fixture. See Figure 2 . 2 .11-4. The assembly consisted of an aft trunnion and support, a forward support, and a main frame. The as sembly was used in conj""ction with the MDA handling fixture attached to the forward support. The function of the liar; zontal Transportation tixture was to provide support for the MDA during air or ground transportation and t o permit the MDA to b~ trunnioned from the horizontal t o the vertical or the vertical to the horizontal attitudes . The fixture provided support for the desiccant breather assembl y during transportation. (See Sbction 2.2.11.2). (3) Design/Test Verification - During the manufacture, and upon completion of the assembly, the fixture was examined to verify conformance of the product to the engineering drawi ngs with r espect to materials, di- mensi.on s, construction, and identificati.:m. Figure 2.2.11- 4 MDA in Transport a tion F:xture Off10aded from Guppy 2-409 .J Proof load testing of the fbture was conducted by statistically loading the assembly to 150 percent of l.ts design loads, ,~ith no evidence of fl'1ilure or de- formation. The fixture was fit check,~d and match drilled to the aircraft pallet, but fit checking to the MDA and handl- ing fixture was not possible prior to delivery and first use of the product. (4) Program Usage - First use of the Horizontal Transporta- tion Fixture was made at MSFC. The assembly was de- livered to MSFC for fit checking, Jon~itudinal align- ments, and mating to the MDA. The assembly was used repeatedly during movements of the MDA for MSFC to Denver, and between the manufacturing, test, thermaL, and high bay facilities. Also, the fixtur.e was used during MDA weight and C.G. determination. See Figure 2.2.11-5. (5) Conclusions ~ The .Horizontal Transportation Fixture en- countered no significant problems in the design, build, or use. The assembly met and satisfied the design and functional requirements imposed by the Skylab program. Performance of the GSE was su.ccessful in each of its uses and the GSE proved to be a highly reliable and safe set of transportation equipment. C. MDA Protection (1) Design Requirements - In general, the philosophy tor the design of protective devices was based on its lo- cation inside the MDA. If a cover could be stepped on, it was designed for a stepping load of 300 pounds. Otherwise, the cover was designed for a pushing load of 150 pounds from any direction. Since the MDA could be oriented to the horizontal, vertical upright, or in- verted attitudes, the design of the protective covers was required to satisfy loading from any direction. It was not made a design requirement to impose impact factors to the covers, but material factors of safety of 2.0 on yield stress and 3.0 on ultiw~te stress were used. 2-410 i N 1- ... ... ' ... ' - -- -:-. - -- , - / - , . r- . / I) .. f· .. f · . 11;1 I =.~./~=- . \ \ \ . \ \ \ \ \. - Figure 2.2.11-5 ~IDA on Weigh t and C. G. Table (2) Description - Protection for sensitive areas and equip- ment in the MDA was provideJ by GSE. Covers were in- stalled over the S190 window, the hatches and hatch seals, and the docking ports. A sealing plate protected the PIM/MDA interface9urface. During equipment instal- lations, checkouts, aru:' other activities in the MDA, protective covers We!e provided for the EREP components, I/LCA,the M5l2, fire detectors, RNBs , valves, and gages. Also, a safety net and a debris catcher were installed to prevent damage to equipment or injury to personnel from dropped objects. (3) Design/Test Verification - During the manufacture and upon completion of the assemblies, they were carefully examined to verify conformance of the products to the engineering drawings with respect to materials, di- mensions, construction, identification, and interface requirements. In general, proof loading of the covers was not re- quired. An exception was the docking port protective sleeves. These flanged covers lined the full length of the tunnels while providing protection to the docking surfaces and the hatch seal. Used extensively during equipment ingress to the MDA, they also became the sole means of access for personnel into the MDA after the MDA was mated to the AM. See Figure 2.2.11-6. (4) Program Usage - Extensive use was made of the protective equipment. Once the covers were installed they remained in place at all times that personnel were working on the MDA. During those times when access to controls or dis- plays was required, covers were removed to facilitate those activities. While handling or transporting the MDA, protective covers were always in place over the S190 window and the docking ports. During air transportation, special environmental protection was provided. (5) Conclusions - The protective devices encountered no sig- nificant problems in the design, build, or use. They met and satisfied the design, functional and interface requirements imposed by the Skylab :,rogram. Performance of the GSE was successful, and as planned. 2-412 """"- - .. .. --- ------- l .... _ . ...... LAP e Figure 2 . 2 .ll-6 Equipme nt for Protection a nd ,Ieeess Jt tile Radiol Docking Port 2-413 '\-- , , L D. MDA Experiment Inbtallation (1) Design Requirements - The criteria used to determine which experiment packages would be provided with handl- ing and installation equipment was based on NASA human engineering requirements contained in ~mFC-STD-267. In general, if the package to be installed weighed more than 35 pounds or required a reach of more than two feet, GSE was provided. Handling loads were as defined in appropriate lCD's. The GSE was designed for a load factor of 1.5 and /1 material safety factor of 2.0 on yield stress and 3.0 on ultimate stress. In order to maintain the MDA cleanliness environment, the GSE was required to be cleaned to Class 100,000 compatibility. All parts such as pins, bolts, and small assemblies were tethered or made captive to the main assembly to prevent dropped objects inside the MDA. (2) Description - The function of the MDA experiment in- stallation equipment was to provide a mechanical means for handling the experiment packages from the bench to the MDA, and the capability to make the final instal- lation. A special set of GSE was required to install and remove EREP experiments. The size, weight and awkward location of the equipment precluded manual handling and dictated basic design requirements. Since the MDA was to be po- sitioned in two attitudes, GSE was designed to accom- modate both the horizontal posture of the MDA at MDAC-E, St. Louis, and the vertical (upright) position at Martin- Denver, and at KSC. GSE was also provided to permit loading experiments into the horizontal MDA, through the radial docking port. This equipment consisted of a rail and cart assembly to winch equipment into the MDA and a hoist and track in- side the MDA to remove and position the experiments. See Figure 2.2.11-6. For access to the equipment lo- cations, a platform assembly for· the full length of the MDA was provided. See Figure 2.2.11-7. A system of handling slings and counterbalances was employed to permit installations on the sides of the MDA. For equip- ment mounted on the exteriur of the MDA; an adjustable lifting fixture was provided. 2-414 • . . ~ . '-; • • \ \ \ , , \ \ Figure 2.2.11 - 7 Horizontal Access Platform For the MDA in the upright position, a hoist and track were secured to ~he underside of the dome. See Figure 2.2.11-8. Figure 2.2.11-8 Hoist and Track Installation Equipment was moved vertically through til!! AM tunnel and out the EVA hatch opening. These operations re- quired a set of sling. and counterbaldnces to be used with handling f rames and fixtures. Access inside the MDA was provided from two platfo"m levels. See Figure 2.2.11-9. 2-ld.6 , .. I • : , : . • P' l. gu r e 2 , 2 II ' - 9 P]"tf orm 2-4 17 and L ' dde r A SScmbl y ·1 \ , Special universal handling frames and fixtures were designed and sling/counterbalance attachments were made to permit rotation of the experiment into any desired attitude. (3) Design/Test Verification - During the manufacture, and upon completion of the assembly, the equipment was ex- amined to verify conformance of the product to the engineering drawings with respect to materials, di- mensions, construction, identification, and interface requirements. Proof load testing of the assemblies was conducted by statically loading them to 150 percent of their design loads with no evidence of failure or deformation. Fit checking of the equipment to the experiments and the MDA was usually made prior to delivery and first use of the item~. A notable exception is described in the following section. (4) Program Usage - First use of the installation equipment was normally made at Denver, as most of the experiments were available. Some experiments were installed, ohecked out, and then removed from an upright MDA in Denver, and were later reinstalled at St. Louis when the MDA was in the horizontal attitude. Thus, all items of GSE that were designated as contingency hardware for use at MDAC-E were utilized in planned activities. Removal of the MS12 prior to the MDA being mated to the AM posed a challenge at MDAC-E. Reinstallation was re- quired to be made of the MSl2 intact into the horizontally positioned AM./MDA. As a consequence, a plan was devised to insert the M512 through the radial dockin~ tunnel. This required a new set of GSE. Because a fit check could nnt be made of the GSE prior to usage, high confidence had to be placed in the design and build verifications, re- sulting in a successful first-time installation. Also used successfully on a first-time basis Without a prior fit check were the internal access platform and ladder assemblies during inverted docking tests. 2-418 ~ " r f I !: (5) Conclusions - The hardware encountered no signif- icant problems in its design, build, or use. It met and satisfied ch., design, functional and interface requirements impo~ed by the Sky1ab program. Per- formance of the GSE was as planned. The hardware proved to be highly reliable and safe equipment, and resulted in the successful installation of all the experiment packages. E. One-G Trainer GSE (1) Design Requirements - Since the One-G Trainer was to be capable of supporting flight crew procedures de- velopment and flight crew training exercises for those experiments performed in the MDA, the Trainer had to have the capability of being placed in either a hor- izontal position or, in a vertical position. I~hen in the horizontal position, the capability to rotate the Trainer about the longitudinal axis was required. Ground handling for loading, erection and transporta- tion of the Trainer by air or ground was required. Design loading conditions were the same as those used for flight hardware GSE. (2) Description - To satisfy these criteria, the follow- ~ng set of GSE was identified: • A handling and installation set - to provide the capability of lifting and positioning the MDA Trainer through the horizontal and vertical po- sitions. See Figure 2.2.11-10. 0 " • A vertical support stand - to support the Trainer in the vertical (launch) position, to peJ:mit personnel entry through the aft end of th~ MDA, and to provide access to the experiments inside the MDA. See Figure 2.2.11-11. A horizontal rotation fixture - to support the MDA Trainer when mechanically interfaced with !,he AM/STS Trainer in the horizontal position and pro- vide manual roll capability ~f the Traine1 about the X-axis. 2-419 Fig ure 2.2.l l-1 0 NDA Tr.l ill e r Erected l o VL'rlil: .JI P \I~llioLl 2-420 Figure 2 .2.1I-1i NO" Trdil'l0r on S"pport Stand 2-421 • A Trainer access stand - to permit personnel access into the aft end of the trainer while on the ro- tation fixture. • A handling fixture and transportation fixture (sim- ilar to those provided for the flight article) - for handling and transporting the MDA Trainer by air or ground. This set was jointly shared with the MDA Dynamic Test Article. (3) Design/Test Veri.fication - During manufacture, and upon completion of the aSGemb1y, all equipment was examined to verify' conformance of the product to the engineer- ing drawings with respect to materials, dimensions, con- struction and identification. Proof load testing was conducted on all assemblies by statically loading them to 150 percent of their design loads with no evidence of failure or excessive deforma- tion. (4) Program Usage - All GSE for the One-G Trainer was de- livered to JSC and was used extensively throughout' all phases of One-G Trainer operations. The equipment contributed substantially to the success of the Trainer. (5) Conclusions - The hardware encountered no significant problems in its design, build or use. It met all re- quirements and proved to be reliable and safe equipment, 2-422 I • 2.2.11.2 Mechanical, Mechanical GSE provided by MMC as CFE started with 3 end items per the origtnal proposal and expanded to eleven deliverable end i~"ms as the MIlA program progressed. The original three pieces of mechanical GSE were the Pneumatic Checkout Console, the Desiccant Breather Assembly, and MDA Shipping Cover Assembly. The other units all evolved from new requirements as the program developed. The mechanical GSE items categ!. rized as transportation support. module support, and experiment support are discussed below. A. Transportation Support - The following items were provided for protection of the MIlA during transportation from Denver to St. Louis and St. Louis to KSC and during any storage modes: • Desiccant Breather Assembly SK820FL5300 • Shipping Cover Assembly SK82OFL5500 The breather assembly and the shipping cover assembly were designed to protect the MIlA from environmental damage or contamina- tion during ground handling and transportation'from Denver or during any storage modes of the MIlA outside of a controlled environment. The breather was also designed to provide protection of tlte AM/MDA during air transportation to KSC. (1) Der-ign Requirements - The design requirements for the breather assembly and the shipping cover assemblies were based on requirements derived from the MDa End Item Specification, CPII4AI000026, NASA Technical Memorandum TMX 53328 for natural environments, and Aerospacelines Report ASL-30 for air transportation criteria. A preliminary design criteria was prepared for,each to establish pressures, temperatures, and general configuration of the hardware for preliminary design reviews since no end item specs were available. (a) The Desiccant Breather Assembly was designed to protect the MDA during handling, transpor- tation, and storage against structurally harmful atmospheric pressure changes and to maintain a clean, dry interior environment within the MDA ahd its shipping cover. Design considerations were mainly concerned with dry- ing capability, filter requirements, maximum air flow conditions vs preSsure drop, and interface criteria. 2-423 i I I ! fI p (b) Tne Snipping Cover Assembly was designed to protect the MIlA from the enviroruncnts lind normal transportation hazards. The assembly was designed as an inner cover to be sealed to maintain a dry and clean envirorunent around the MDA and an outer cover of more rugged material to protect the inner cover from external damage. Design considerations were concentrated on compatible materials and proper configuration and size for installing and removing the covers in the areas prescribed for this operation. (2) Functional Description - Tne breather and cover assemblies (See Figures 2.~.11-12 and 2.2.11-13) were designed to f,mction together for protection of the MDA. The breather allowed the MIlA and the inner cover to breathe clean dry air by directing all air through a desiccant bed and filter assemblies of proper size and capacity for the air inside to be dry and the pressure drop at maximum £101. rates to be less than 0.5 psid (maximum allowableAP per the MIlA-CEI). Prior to connecting the breather assembly to the system ,the interior of the MDA and the inner cover were purged to a low dew point to remove moisture inside and assure no condensation would occur. A brief description of each unit is as follows: (a) The Desiccant Breather Assembly consisted of a desiccant canister assembly, a humidity indicator, filter assemblies, flex hoses, adapters, and other miscellaneous hardware such as clamps. The Air Carry Unit was a large unit designed to meet the higher-capacity requirements during air carry; the smaller Ground Handling Unit could remain attached to the MIlA during ground handling operations. The desiccant canister assemblies consisted of a desiccant container sized to flow the required air to or from the AM/MDA and main- tain tne humidity level within the MDA and the AM/MDA wnile preventing tne outside-to- 2-424 I I -- f " F'ILTU. ASS'I (I"DA ill .j FILTER J.SS"! Figure 2 . 2.1 1- 12 Desiccant Breather Assembly (SK820FL5300) .- \ • • . . • I . .. - Figure 2.2.11 -13 Shipping Cover Assembly (SK820FL5500) inside pressure differential from exceeding 0.5 psid. The Air Carry Unit also provided a separate outlet to supply dry air Co the MDA Shipping Cover Assembly. (b) The MDA Shipping Cover Assembly cons is ted of inner and outer covers. 'l'he inner cover was a water-proof enclosure of plastic film (VELAS~T) designed to eliminate moisture and other contaminants from contacting the outer surfaces of the MDA. The MDA Desiccant Breather Asaembly was attached to the inner cover during ground and air transportation • . i The outer cover was installed over the MDA Inner Cover to provide protection against physical damage resulting from weather and dirt conditions encountered in transit and storage. It was made of durable waterproof and flame resistant material (H¥PALON) that provided maximum protection during shipment. It attached to the Horizontal Transportatio~ Fixture by ropes thru eyelets in the cover and hooks on the transportation fixture. (3) Design/Test Verification - During manufacture, and upon completion of each assembly, the units were examined to verify conformance to the engineering drawings with respect to materials, dimensions, construction, identification, and interface require- ments. Acceptance tests were also conducted on each assembly to assure design verification with intended use of the item. The breather assembly was tested for its capability to meet flow VB pressure drop, moisture removal and general assembly configurations and interface verifications. The shipping cover tests included proof pressure and leak test of the inner cover and complete inspection of all units for com- pliance with engineering drawings. Fit checks on the Breather and Cover Assemblies for the flight and backup articles were also completed. Some alterations to inner cover were required as a result of the fit check and retests were conducted. All tests were completed successfully for each assembly. 200427 (4) Program Usage - First usage of the breather assembly and the shipping cover assembly was during preparation of the flight article for shipment from Denver to St. Louis. The assemblieB were used again in the same con- figuration for the backup article. The breather assembly was incorporated into a shipping plan provided by MDAC-E for thl! AM/MDA configuration. (5) Conclusions - The breather assembly and the cover assembly encountered no significant problems during design, build or use. The assemblies met and satisfied the design, functional., and interface requirements imposed by the SkylabProgram. B. MDA Module Support - The following items were provided for support of the MDA Module testing at Denver, St. Louis, and KSC: Volumetrics Leak Detection Unit (VLDU) Pneumatic Checkout Console MDA/CSM Leak Detection Kit MDA Fan Test Set Coolant Rystem Checkout Unit (CSCU) Water Ch .. -"ler Unit M512 Vent Adapter Assembly Leak Detection Adapter Kit SK820FL5010 SK820FL5100 SK820FL5200 SK820FL5400 SK820FL5700 SK820FL5800 SK820FL5900 SK820FL6464 Some of the above items were used for support of experiment testing as well as MDA module support. Design of each item was based on the known usage requirements at the time of de~ign. (1) Design Requirements - The design requirements for each of the end item assemblies were based on requirements derived from the MDA End Item Specification, CPl14AI000026, applicable ICDs, and actual usage requirements for the unit. A preliminary design criteria was prepared for each item to establish criteria such as pressures, temperatures, and general configuration of the hardware for preliminary design reviews since no end item specifications were available. In some cases trade studies were completed to determine which method or leak measurement would be used. Some of the unitH were initially designed as non- 2-428 · I (2) I .. .I .I. ______ ~ deliverable GSE and later converted to d~liverablc GSE in which case changes were worked to upgrade thl' units for more universal usage. In general each unit was designed using standard off-the-shelf components wherever possible, with Similarity to previously used hardware for added design assurance without special qualification testing. Functional Description - A brief description of each unit is as follows: (a) (VLDU) and the Leak Detection Adapter Kit - The VLDU (SK820FL50l0) was used to measure the leakage rate of MDA subsystems aud experiments. The Leak Detection Adapter Kit (SK820FL6464) provided the hose assemblies, filters, and adapters required to connect the VLDU to the flight article being tested and to the facility gaseous nitrogen (GN2) supply. The VLDU also interfaced with facility 115 VAC, 60 Hz, single-phase electrical power. The VLDU was approximately 25.5 inches wide by 27.25 inches deep by 36.5 inches high and weighed approximately 150 pounds. Major sub- systems were a pneumatic system and an electricall electronic system. BaSically, the VLDU utilized a volumetrics micrometer to measure the precise volumetric change required to neutralize the pressure change resulting from leakage of the test article. Charge pressures from zero to 60 psig could be used. The VLDU had the capability of determining the test article leakage rate by maintaining a constant differential pressure or by determining the drop in pressure over a timed interval. Leakage rates from 100 sec/min to 1.0 x 10-3 sec/sec could b,~ measured. (b) Pneumatic Checkout Console - The Pneumatic Checkout Console (SK280FL5100) was used to control, measure, and monitor the facility nitrogen gas used during the Leakage Rate Measurement and Purge Manifold tests on the MDA. It consisted of the console, reference volume kit, flex hoses and flowmeter kit. 2-42~' The console contained thu controls, indicators, and pneumatic circuits required to perform the test functions. The pneumatic circuits con- sisted of high flow circuit, a low flOl, circult, and a diifcrunCial pressure circuit. 'fhe dHfurentia1 prussure circuit was isolated from the high and low flow circuits. The reference volume kit assembled to the STS Simu1a tor Sealing Plate Assembly on the ~IDA and was connected to the console by flax hoses. A flex hose assembly was used to connect the console to the facility gaseous nitrogen supply. The flowmeter kit consisted of a portable flowmeter and a 15 foot length of clear vinyl tubing. The Pneumatic Checkout Console operated in a clean environment locB~ed within 65 feet of the test article and 35 feet of the facility nitrogen supply because of the flex hose lengths. TIle hoses were restrained when pressurized and, whell laid across floor areas ,were protected by barricades or covers to avoid damage from vehicular or personnel traffic over them. Facility nitrogen used met the requirements of MIL-P-27401B and was capable of supplying a flow of up to five pounds per minute at a pressure of 150 to 475 psig for the duration of the tes ts. (c) MDA/CSM Leak Detection Ki, - The MDA/CSM Leak Detection Kit (SK820FL5200) was used to mea~~re gas leakage from the MDA and Command and Service Module (CSM) interface. TIlis leakage test was performed during the AM/MDA inverted docking test with the CSM in the WITS of the O&C Building at KSC. The kit was housed in a portable aluminum carrying caee approxil1'ate1y 15 by 12 by 13 inches. Components assembled and installed in the bottom of the case were a thermowe1l assembly, two f1owmeters, a thermometer, a three-way valve, and associated plumbing and hardware. Removable componerits stored in the stowage space in the upper half of the 2-430 I \ I case that completed the kit were: • Spring - to provide a flow channel for leakage gas at the MlJA/CSM interface, • White vinyl tape that laid over the spring to form a leakage collector cavity, • Tee assetnbly that mated with the sprlng and tape to form a leakage connection point from the leakage collector cavity, • A piece of flex tubing that connected between the tee assembly and inlet fitting of the kit, • Flowmeter that could replace one of the flowmeters installed in the case if additional flowmeter range was required, • Spare disc filters, • Leather punch used to punch a hole in th" tape for the tee assembly installation, and • G~-43 sealant that provided a seal for the assembly. The test setup was obtained by creating and then connecting a leak collector cavity at the MDA/CSM interface to the gas flo\~ measure- ment equipment in the carrying case. (d) MDA Fan Test Set - The MDA Fan Test Set (SK829FL5400) was ~sed to check the perfor- mance of the fans in the MDA ventilation system. It consisted of an Air Velocity Meter Set, an Inlet Adapter Assembly, an Electrical Set, and a Shipping/Storage Container Assembly. The Air Velocity Meter Set consisted of a velometer, range selector, diffuser probe, pilot probe assembly, and tubing. It was used at the air inlet to the CSM duct fan to measure the CSM air supply and at the MDA diffuser outlet to determine the MDA cabin fan air velocity. The Inlet Adapter Assembly was used to position the diffuser probe during measurement of the CSM air supply. It interfaced on the screen side of the inlet muffler assembly and was held in place with tapc. TIle Electrical Set was used to control and measure electrical power to the applicable MDA fan during the testing functions. It was inserted between the MIlA airborne wiring and the applicable fan and supplied electrical power of 26 ± 0.1 VDC and approximately 350 W. via the airborne wiring. The Shipping/Storage Container Assembly was a light weigh~ aluminum carrying case filled with Scott l'irell foam. Cutouts were provided in the foam for test components to restrict movement to a minimum during handling and shipping. (e) (CSCU) and Water Chiller Unit - The CSCU (SK280FL5700), was used to check out the ~IDA coolant loop. It consisted of a mobile cabinet containing a liqui.d reservoir, pump, interface fittings and hoses, and the associated control and meas'Jring components. It used facility nitrogen and 115 VAC, 60 Hz, single phase power. 'rhe CSCU was desib'lled to circulate a flow of coolant fluid through the MIlA coolant loops and to measure the flow versus differential pressure. A pneumatic circuit was included to permit purging and drying of the liquid flow circuit. An auxiliary Water Chiller Unit (SK820FL5800) was connected into the coolant return lines between the MIlA and CSCU for t"sts requiring cooling capability. The Water Chiller Unit'was used to maintain the temperature of the MIlA coolant system fluid between 490 F and 780 F during testing functions. It was a cast cooler package manufactured by Dunham-Bush, incorporated and 2-432 I \ modified by ~tHC. It was approximately 27 inches high by 21.5 in"h"s \~ide by 24 inches deep, with two rigJ.d and two S\~ivel castcrn to provide easy movement, and operated on 115 VAC, 60 Hz, single phase facility power. (f) M5l2 V,mt Adapter Assl'mbly - The M512 Vent Adapter Assembly (SI<820FJ.5900), providcd an intcrfacc connector between the pressure supply or vacuum pump ami the 1-1512 Experiment vent system. It \~as used for the leak check, experiment vacuum tests, ond Lor protecti.on during transportatioll. The assembly consisted of an aluminum cylinder with one end threaded and one end [langed, gaske ts, a blind nanf~'" a tub" fitting with cap, and mounting hnrdwurc for the blind flangH. The cap was removed and the pressure supply connected to the tube fitting during the leak checlt. The blind flange \~as rel1"lVed and the vacuum pump connected to the adapter flunge interface for vacuum testing. (3) Design/Test V"rification - During manufacture, and upon completion of each assembly, the units were uxaminecl to verify conformance to the engineeri.ng drawings with respect to materials, dimensions, construction, identification, and interface requirements. Acceptance tests were alr.o conducted on each assembly to assure desi.gn verification with intended usc of the item. All end item units were subjected to tests such as proof pressure, leakage, functional, flow and temperuture control, as applicable to verify design capability versus usage requirements. When schedule allowed, fit check were conducted prior to actual usage to verify interfaces. (4) Program Usage - Usage of tlte GSE items described herein w(\s as follows: 2-433 (a) The VLDU was used at KSc.: [or the H5l2 leakage tests, H5l2 battery vent leakage, and tunnel leak tests. A similar unit o[ capital equipment (non USE) was used for similar tests at Denver and KSC and was not available [or usc at KSC. (b) The Pneumatic Checkout Console was used at Denver only for the HDA leakage tests, insulation purge tests and various other unscheduled usages requiring nitrogen within the dean room area during the flight and backup test periods in the high bay at Denver. (c) The WA/CSM Leak Detection Kit was used at KSC during the inverted docking test to measure the leakage at the MDA/CSM interface. (d) The HDA Fan Test Set was used at St. Louis with the flight article and at Denv'3r with the backup article to measure air capacity of the MDA fans. (e) The CSCU and the Water Chiller Unit were used at Denver and St. Louis during all usages of EREP & ATr.! C&D coolant system on flight and backup articles to supply coolant as well as to verify flow and pressure drop data on the system. The units were used also at St. Louis during bench tests on the EREP system. (f) The MSl2 Vent Adapter Assemblies were installed at Denver on the flight and backup articles. These units remained on the HDA until after completion of tests at KSC. The flight article unit was removed before flight at KSC. The backup article unit remained installed through storage. These items were used for M512 leakage and VaCUum tests conducted at Denver, St. Louis and KSC anq also provided interface protection during all other times. (5) Conclusions - None of the GSE items described herein encountered any significant problems in design, build or use. The units met and satisfied the design, function, snd interface requirements imposed by the Sky lab Program • . 2-434 I C. MIlA Experiments Support - One itrm, the Internal Scanner Ground coolant Adapter Kit, SK820FL5600, was only provided for experiment support. Other units mentioned above, however, were used in support of various experUnent tests mostly on module with some off module tests supported. 'rhe SK820FL501O, SK820FL5900, and SK820FL6464 were used to support MS12 on-module tests; SK870FL5l00, SK87FL5700, SK820FL5800, and SK870FL6464 were used to support o~ module and off module EREP tests at Denver and St. Louis. (1) Design Requirements - The Internal Scanner Ground Coolant Adapter Kit was required to furnish a supply and return flex hose from the axial docking port closure plate to the inlet and outlet fitt'.ngs at the 8192 Internal Scanner Heat Pipe Condenser and Cover f01: usc during the Altitude Chamber Test in St. Louis. Two standard off the shelf hoses 01 correct length Were provided for this usc. . (2) "unctional Description (a) The Internal Scanner Ground Coolant Adapter Kit supplied the cooling flow loop within the MIlA. During the tests the atmosphere in the }IDA varied from sea level ambient atmospheric conditions to an oxygen enriched atmosphere at approximately 5.0 psia. The two coolant hoses were ~ inch in diameter, 21 feet long, and consisted of an inner teflon liner with a wire braided outer jacket and corrosion resistant ,AN hose fittings. One end of each hose had a straight swivel nut flared fitting and the other end had a 900 swivel nut flared fitting. The Internal Scanner Ground Coolant Adapter Kit was part of the GSE required to provide coolant to the S192 Internal Scanner during the Altitude Chamber Tests at }WAC-E. It conSisted of two hoses that connected the inlet and outlet fittings at the S192 Internal Scanner Heat Pipe Condenser and Cover '. i __ ............ . I ~ (F21005807) to pass through fittings in till! MDAC-E Axial Docking Port Closure Plate (61E010044). MDAC-E tubing, hoses, and fittings, completed the supply and return flow loop to the Heat Pipe Condenser Water Cooling System (F21005644-102) on the outside of the altitude chamber. The. completed assembly transferred heat from the Cooler-Dewar-Preamp Assembly Engine Cooler by circulating distilled water at 0.5 gpm minimum through a heat exchanger attached to the wall of the engine cooler. (b) The VLDU and the Leak Detection Adapter Kit were used for leak testing of the N5l2 experiment at KSC. Reference 2.2.11.2.8 for details on these units. (c) The CSCU and Water Chiller provided coolant flow during EREP testing at St. Louis for on-module and off module tests. Reference 2.2.11.2.8 for details on these items. (3) Design/Test Verification - The hoses of the Ground Coolant Adapter Kit were proof pressure tested, leak tested, and inspected to meet the engineering drawing requirements for proper identification, cleanliness, and packaging. (4) Program Usage - The Ground Coolant Adapter Kit was not used since the S192 was not installed for the altitude test st St. Louis. (5) Conclusions - The Ground Coolp.nt Adapter kit was provided with no problems ene, 'untered during design or build and tests verified the item would function as required. This unit employed commonly used flex hoses and could be used for many other purposes where flex hoses are required. 2-436 r 2.2.11.3 Electrical A. Test Ligllting, SK820FL6461 (Figure 2.2.11-14) (1) Design Requirenlents - Provide electrical lighting for operllt ions within the ~!nA. Figure 2.2.11-14 Test Lighting Fixture (2) Functional Description - The Test Lighting Fixture provided electricol lighting for operations within the MDA, in lieu of using the MDA internal lights. The fixture consisted of

MSFC Skylab Multiple Docking Adapter, Volume 1

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