Haddad, Michael E.

English

Embry-Riddle Aeronautical University

The Space Congress® Proceedings 1999 (36th) Countdown to the Millennium Apr 28th, 2:00 PM Paper Session II-B - Combining Tools, Tasks, Flight Hardware & Astronauts in Pre-flight Ground Fit Checks for On-orbit Success Michael E. Haddad NASA Kennedy Space Center Follow this and additional works at: https://commons.erau.edu/space-congress-proceedings Scholarly Commons Citation Haddad, Michael E., "Paper Session II-B - Combining Tools, Tasks, Flight Hardware & Astronauts in Pre-flight Ground Fit Checks for On-orbit Success" (1999). The Space Congress® Proceedings. 12. https://commons.erau.edu/space-congress-proceedings/proceedings-1999-36th/april-28-1999/12 This Event is brought to you for free and open access by the Conferences at Scholarly Commons. It has been accepted for inclusion in The Space Congress® Proceedings by an authorized administrator of Scholarly Commons. For more information, please contact commons@erau.edu. 136th Space CongressApril 27 – April 30, 1999Combining Tools, Tasks, Flight Hardware and AstronautPre-Flight Ground Fit ChecksFor On-Orbit SuccessbyMichael E. HaddadNASAKennedy Space CenterAbstract:This paper will discuss the process of performing “Fit checks” which refers to mating flighthardware together on the ground before they will be mated on-or it.  The concept seems simplebut it can be difficult to perform operations like this on the ground when the flight ardware isbeing designed to be mated on-orbit in a zero-g and/or vacuum environment of spAls  someof the items are manufactured years apart so how are fit checks performed on thesecomponents if one piece is on-orbit before its mating piece is planned to be buBoth the InternalVehicular Activity (IVA) and Extra-Vehicular Activity (EVA) fit checks will be presented. Detailsinclude; how fit checks should mimic on-orbit operational scenarios,  series of photographs willbe included that were taken during fit checks performed on International Space Station (ISS)flight elements and the paper will conclude with lessons learned as a result o2Fit Check Definition:Fit check refers to mating two (or more) flight items together on the ground. Fi  c cks can relateto an electrical ble being mated between first ISS element Unity and the Laboratory element,fluid line being mated between Unity and the Airlock, two pieces of structure being matedtogether like the Ku-band antenna and its boom, or an Or italReplaceable Unit (ORU) mounted toits on-orbit location. ORU’s, like batteries orelectronic boxes, are items that can be installed on-orbit by the Astronauts/Cosmonauts, or on the ground before launch, with the capability oberemoved/repositioned at a later time as part of normal on-orbit maintenance ope ations.  Example;if battery replacement is necessary, everything possible needs to be done ahead of time toassure this item can be removed and replaced with a good battery. Fit checks help assure thischange-out of hardware is successful.  Some times flight-to-flight fit checksare not possible, somaster units, which simulate the flight items should be used, but only as a la t resort. All effortsshould be made to use flight hardware. Note: For purposes of this paper,Astronauts/Cosmonauts will be refereed to as the “Crew”.On-orbit Operational Scenarios:The fit check a ts like a dry run for the actual on-orbit operations that will be performed by theCrew. These operations could be IVA or EVA related which are part of the normal assemblysequence of Space Station, part of a contingency plan regarding repairs for failures on-orbit oroff-nominal sequence that is critical to allowing assembly operations to continue. Fit checks ofthe hardware will usually determine the proper order, or sequence of events that n ed to ccur.Planning takes place on what the Crew should do to accomplish a task, and the fit checkvalidates the planning.Internal Vehicular Activity (IVA):IVA relates to tasks performed by the Crew in a shirtsleeve environment internal topressurizedSpace Station Elements, like Unity, the Laboratory Module and Airlock Module. An IVA task couldbe as simple as turning a valve, to connecting 20+ electrical and fluid lines between ISSelements, or total activation ofthe new ISS element that has just arrive on-orbit.  IVA task canperform by ‘Station Crews” that are permanently occupying the Space Station or Crews aboardvehicles just launched from Earth.  Many IVA tasks can be performed at the same time becausethe large numbers of crew members present inside the pressurized ISS elements.  What iscritical to IVA operations is usually the sequence of steps that need to be performed andmaintaining a certain order of tasks, one-after-another, to assure successful c mpletion. Stand-alone IVA task are mostly straightforward, but the problem occurs when IVA tasks areintegrated with other operations, like berthing an element on-orbit.  IVA pr -flight fichecksallowthe Crew to perform a dry run of what they will ctually be performing in Space using the sameflight tools, flight hardware and sequence of steps (flight procedure).  IVA can be similartonormal tools used every day here on Earth.  Access to hardware is relatively asy and the flighthardware can be designed and operated very similar to normal every day operations on theground. This allows extra time and resources to solve any problems that may occur during theIVA operations. Even with these similarities o ground operations, fit checks are mandatory toassure successful operations, because if something does not work on-orbit, heonly way to fixit may be to bring it back to the ground, which nobody wants to do.  Photo #1 an IVA taskperformed by the STS-88 flight crew during their mission in December 1998. 3Photo#1 – Bob Cabana & Sergei Krikalev areabout to open the Unity Forward hatchallowing access into the Unity ISS element.Note the flight procedure being checked toassure proper steps are followed.Extra-Vehicular Activity (EVA):EVA, unlike IVA, is performed out in the vacuum of space.  The EVA Crew wears suit containing breathing, pressured & temperature controlled environment.  Ththe crew can spend EVA do to limited consumables in the suit.  Also, special tneed to be designed, plus most EVA operations will take place with only two crthus limiting the number of tasks performed during each EVA operation.  The crsome many tools and pieces of hardware. Even though there are toolboxes and looutside of ISS to mount more tools and hardware the crew only has two hands wistorage locations on the suit.  Plus having limited time in the suit, the crew back n forth to all the different locations on the ISS to retrieve more items. operations, crews launched from the ground will be performing most of the EVA which limits the number of EVA operations per mission. EVA Fit checks are thenthere is very little extra time or extra resources to fix problems.  Tools havhardware have to fit, mechanical devices have to function everytime during an EVA fit checks, performed by the crew during pre-flight activities, will combspecial flight/flight-like tools with the flight hardware and the planned procfit the hardware, no interference’s exist between the tools & other hardware,together as planned and that the procedures are accurate and have all the detaperform the task.  As with IVA, EVA tasks and the order they are performed coudifference between success and failure.Photo #2 - STS-88 EVA crew, Jim Newmanand Jerry Ross during EVA activities on theFirst U.S. ISS mission (ISS-2A) that berthedthe Unity Element with the Zarya Element inDecember of 1998.4Lessons Learned:Lessons learned on each mission are applied to future missions.  This will avot e amemistakes over-and-over again, help in the desig process to get a better data base on which todraw from when designing new fight hardware, assist problem solving if similar situations occurdue to error or unexpected hardware failure and allows the ISS programto grow and gain moreexperience on how to live and work in space.The following is a series of lessons learned while performing pre-fight fit checks duringassembly, integration and testing for the first two planned U.S. ISS missions. Reference to on-orbit operations will be discussed and how the fit checks contributed to the successful first U.S.ISS flight. These are just a subse of a larger database of lessons learned while working thesemissions.  As of this writing, the first U.S. ISS element, Unity, is berthed to the Russian Zaryaelement on-orbit, and the Z1 truss, P6 segment, Laboratory Module and Multiple PressurizedLogistic Module are located in the Space Station Processing Facility (SSPF) at Kennedy SpaceCenter.  All ground photo’s shown were taken in the SSPF.Static Fit Checks:As the name implies, these are fit checks that are static in nature.  Examples include an EVA fitcheck of thermal blankets over electronic boxes and an IVA electrical & fluid connector mate tothe Unity.  Because Unity is the core element to ISS, 5 future flights will berand containmany Electrical and Fluid cables/connections between Unity and the new ISS elements.  Aprocess was put in place to fit check all future fluid and electrical jumpers that will make theseconnections. This meant accelerating many future IVA jumpers to allow the fit checks to occurbefore Unity was launched.  Some of the jumpers required tools that will be described later inthis paper, but most were a simple static mate to assure the two items would mate on-orbit.Lesson learned, perform fit checks even for static cases.Photo #3 – Astronaut Jerry Ross fit checksthermal cover that will be placed the UnityMultiplexer/Demultiplexer (MDM) during STS-88 EVA operations.  Note additional Velcrolocation needed to secure strap.Photo #4 – IVA Fluid jumper mates properto fitting but interferes with near-bystructure. Solution, modify end of jumpewith “S” fitting.5Photo #5 - EVA glove gets caught betweenhandrail and shield.  Solution, place 1”spacer under handrail to allow more volumebetween handrail from shield.Photo #6 - Successful glove use duringSTS-88 EVA operations, in December 1998.Dynamic Fit Checks:Dynamic fit checks deal with items that once placed in a desire location, have dynamiccomponents that if not exercised during fit check could cause on-orbit problem Ph to# 7 is heS-Band Antenna Subassembly (SASA) boom, SASA not.  On-orbit the high gain antenna of theSASA can pivot and rotate so this ame operation was performed uring the dynamic fit checkand it was discovered more space was required between the end of the high gain antenna andboom.  This never would have been caught if the team had performed onlya “static” fit check ofthe SASA to its boom.  Lesson learned, perform dynamic fit check not just static fit check ifapplicable.Photo #7 – Dynamic fit check of The S-Band Antenna Subassembly (SASA), not shown notedmore space was needed between the high gain antenna and boom. Solution, modify 6Flight Configuration:Photo’s #8 & #9 are of the Crew Equipment Translation Aid (CETA) light boom fitto Unity atlaunch Pad 39A.  Photo #8 is just of the in erface bracket o Unity which fits just fine, but whenthe boom is added, Photo #9, i.e. now the boom assembly is in its flight configuration, the boominterferes with surrounding blanket material.  Lesson learned, perform fit chehardwa einits flight configuration.  Even a temporary installation of flight hardware insurrounding area isbetter than not having any hardware. Note: This fit check was very late in thep ocessingflow, so if the problem could not be solved quickly, delaying the launch may have resulted.Lesson learned, perform fit check as early as possible with flight hardware in flightconfiguration.Photo #8 - CETA light boom interface bracketfit check to Unity, minus boom.  Fit checkgood.Photo #9 - CETA light boom interface bracketfit check to Unity, including boom. Boominterferes with blanket not allowing boom tofully seat. Solution, reposition blanketmaterial.Assure Ground Support Equipment (GSE) is Compatible with Fit Check:In an attempt to perform static and/or dynamic fit checks, the GSE can interfere withaccomplishing the complete fit check.  Photo # 10 is a picture of Unity in its Element RotationStand (ERS), white structure with markings, located in the SSPF.  The CETA light boom, statedabove, is approximately 4 feet long and is to be fit checked at the white blanket area located inthe middle of the photo.  The problem is the ERS ring is closer than 4 feet, thstaticfit check of the CETA light boom (which forced the fit check at the launch pad).  Photo #11shows a lifting sling interfering with opening the EVA Tool Storage Device (ETSD) door during adynamic fit check.  The sling needed to continually support the box during fitcheck, thus the legscould not be removed to allow door opening.  Lessons learned, assure GSE is compatible withstatic and dynamic fit checks.7Photo #10 - ERS prevents fi  check of 4-footlong CETA light boom. Solution fit check atthe launch pad. Photo #11 - Sling leg prevents ETSD doorsfrom being opened during dynamic fit check.Solution, create template of door.Tools:Fit checks of flight/flight-like tools to flight hardware is mandatory.  Many the tools will work as planned, but until the tool is placed in with the flighthere is no way to know for sure.   The tool may fit the item perfectly, but tthe tool may prevent using the tool in the manner desired.  Lessons learned, wcheck, use tools (or flight-like) that will be used during the on-orbit operatPhoto # 12 – Tether fit check used to releaseCBM deployable cover launch locks duringSTS-88 EVA operations.  The tether workedgreat on-orbit.Photo #13 – Fluid fitting torque device check to Unity fluid fitting.  Device fibut personnel need to assure surroundinghardware will not interfere with operat8Lessons learned from previous Shuttle missions:The following is a summation of information contained in NASA Document,  NSTS 0VOLUME XIV, Appendix 7 (Formerly JSC 10615) System Description and Design Data-Extravehicular ActivitiesShuttle mission 41C - Solar Max captureThe objective of the first EVA, EVA-1, was to fly about 200 feet to the satelldock to the satellite, arrest its spin rate with the MMU thrusters, orient it grapple with the RMS, secure it in the payload bay, and start repair.  EVA-1 bmorning of April 8, 1984.  The docking attempts using the MMU were.  Three attemade, but the Trunnion Pin Attachment Device (TPAD) would not grasp the trunniosatellite.  It was later found that this was due to a poorly documented thermapin, which kept the TPAD jaws from clamping on the trunnion.51A - PALAPA & WESTAR satellite retrievalOn Mission 51-A, the first EVA took place on flight day 5, November 12, 1984.One major problem was encountered when one of the waveguides on the PALAPA satextended beyond the radial distance and interfered with the Angle Brace on theStructure (ABS) Common Bracket Clamp (CBC).  Because of this interference, the be installed and used for handling the Satellite with the RMS during installatiberthing adapter.Conclusion:Fit checks are mandatory to help assure mission success.  Planning the fit cheprocess will help avoid problems during the fit check.  Coordinate the use of and to make sure the flight hardware is configured in flight/flight-like confiwill be a static and/or dynamic fit check, does the GSE support the planned fiwhole operation compatible with the Crew and the work they have to perform to actual operation on-orbit.  Building on lessons learned from previous missionsof these elements are needed to assure the fit check mimics the on-orbit operacomes time to perform the real operation, in orbit above the Earth, moving at 1operation will be a success.

Paper Session II-B - Combining Tools, Tasks, Flight Hardware & Astronauts in Pre-flight Ground Fit Checks for On-orbit Success

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Paper Session II-B - Combining Tools, Tasks, Flight Hardware & Astronauts in Pre-flight Ground Fit Checks for On-orbit Success

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