System for removing and repairing spacecraft control thrusters by use of portable air lock

Hethcoat, J. P.

Norton, R. H.

English

NASA Technical Reports Server

I3CPLY TO 
ATTN OF: G p  
TO: 
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION 
WASHINGTON. D.C. 20546 
u ~ I / ~ c i e n t i f i c  & Technical Infomation Division 
Attention: M i s s  Winnie M. Morgan 
FROM: ~ ~ / 0 f f i c e  of Assistagt General Counsel fo r  
Patent Matters 
T I 
SUBJECT: Announcement of NASA-Owned U. S. Patents i n  STAR 
In accordance with the procedures agreed upon by Code GP 
and Code U S I ,  the attached NASA-owned U. S. Patent is being 
forwarded f o r  abstracting and announcement i n  NASA STAR. 
The following information is provided: 
U. S. Patent No. 
Government or  
Corporate Employee 
Supplementary Corporate 
Source ( i f  applicable) t 
NASA Patent Case NO. : ~ F ~ 4 2 ' 3 s  
NOTE - I f  t h i s  patent  covers an invention made by a corporate 
employee of a NASA the following is applicable: 
NO 0 
Pursuant t o  Section National Aeronautics and 
Space Act, the name of the Administrator of NASA appears on 
the f i rs t  page of the patent: however, the name of the actual  
inventor (author) appears at the  heading of Column No. 1 of 
the Specification, following the words a. . . with respect t o  
https://ntrs.nasa.gov/search.jsp?R=19710017619 2020-03-17T03:08:10+00:00Z
Patented March 30, 1971 
3 Sheets-Sheet 1 
APPLICANT: 
Thomas Q Paine, Administrator of 
NASA with respect to an invention of 
Jerry P Hethcoot and Rdand H  arto on/*;; >>$ 
'96 
FIG. 2 
APPLICANT: 
Thomas 0. Paine, Adminisbator of 
NASA with respect t o  an iwveraiiion of 
Jerry I? Hethcoat and Roland H. Norton 
Patented March 30, 1971 
3 Sneets-Sheet 3 
\ Thomas 0. Paine, Administrator OF 
NASA with respect to an invention of 
Jerry P Hethcoat and Roland H.l'dwlon 
United States Patent i l l 1  3,572,610 
1721 Inventors T. 0. Paine 3,286,952 111966 Seeler .......................... 243/1 (S.S.; 
Administrator of the National Aesonamtics 3,386.685 611968 Judd ............................. 24411 (S.S.) 
and Space Adminisbration with respect to FOREIGN P A T E N S  
an inwntion of; 
......................... Jerry P. RethcoaB; &land 8. Nofioea, 1,461,529 1 111966 France 24411(S.S.) 
Huntsville, Calif. Primary Examiner-Milton Buchler 
1211 A ~ o l . N o .  aO.176 Assistant Examiner-Jeffrey L. Forman 
i22 j ~ i i e d  ~u1;9,1"39 
[45] Patented Mar. 30, 197 1 
Atrornqs-L. D. Wofford, jr., G T. McCoy and C C. WeiEs, 
Jr. 
[54] THRUSTER MAINTENANCE SYSTEM 
5 Claims, 5 Drawing Figs. 
....................... [52] U.S.CI ................... . .... . 24411 
[5 1 ] Int. CI ................................................... B64g 1/00 
1501 FieldofSearch ............................................ 244i1 (SS); 
31211: 212.1; 12811: 61/82.113;49168 
[561 References Cited 
UNITED STATES PATENTS 
3,073,040 111 963 Schueller ...................... 244.11 (S.S.)X 
PaaPSmACT: A system for maintenance of a spacecraft 
thruster. The thruster is rnounted on the exterior surface of ;a 
panel removably mounted on the spacecraft wall. A portable 
airlock is provided which may be removably sealed to the En- 
terior surface of the spacecraft wall about the removable 
panel. An operator within the spacecraft inserts his arms into 
space suit-type gloves extending into the airiock which enable 
him to remove the thruster panel and replace it with a new 
panel, afterwhich the portable airlock may be rzrnovcci from 
the spacecraft wall. 
1 
TMPIILISIFER MAINTENANCE SYSTEM 
ORIGIN OF THE INVENTION 
The invention described herein was made in the per- 
fomance of work under a NASA contract and is subject to the ' 
provisions of Section 305 of the National Aeronautics and 
Space Act of 1958, Public Law 85-568 ( 7 2  Stat. 435; 42 
USC 2457). 
BACKGROUND OF W E  INVENTION 10 
1. Field of the Invention 
The present invention relates to a spacecraft maintenance 
system and more specifically to a system for removing and 
repai~ng spacecraft control thrusters by the use of a portable 15 
airlock. 
2. &scription of the Prior Art 
The anitude control thruster systems used on space vehicles 
send stafions occasionally proved to be faulty or otherwise in- 
e r a r i v e  while in outer space. It has been proposed that as- 20 
tronmts u n d e d e  to leave the spacecraft and replace the 
faulQ thruster assembly. Yet this necessarily requires the two 
or more astronauts to don their space suits, activate the main 
~ r l o c h ,  and expose themselves to a hazardous space environ- 
ment. While it is considered irngortant that space vehicles or 25 
sQfions minimize the requirement of manned extravehicular 
activity, no device or spacecraft design has been made which 
will rnake possible the maintenance, repair, or replacement of 
an aaitude control thruster without such activity. 
30 
SUMMARY OFTME INVENTION 
In the present invention, the spacecraft control thruster 
system is mounted on a removable external wall panel of the 
specra f i .  A portable airlock having an opening in its back 35 
side is removably sealed to the inner surface of the spacecraft 
wall so the opening surrounds the removable panel. The air- 
la:k has a window to enable an operator to view the interior of 
the krlock. Also, the airlock has space suit-type gloves ex- 
tending into its interior which enables an operator to insert his 40 
m s  and hands thereinto and remove or otherwise manipulate 
the thmster panel. By having a new thruster panel within the 
airlock, the operator may replace the faulty thruster with a 
p n e l  having a new thruster unit. The airlock may then be 
removed and used in another location. 45 
Aaordingly, it is an object of the present invention to pro- 
vide a spacecraft system for removing thrusters units by an as- 
tronaut inside the spacecraft. 
Another object is to provide a substantially portable airlock 
which may be sealed to a spacecraft wall and enable an as- 50 
tronaut to perfom activities respecting the wall. 
Other objects and advantages of the present invention will 
become more apparent from the following detailed descrip- 
tion when taken together with the accompanying drawings. 
< < 
J 2 
BRIEF DESCRIPTION OF TNE DRAWINGS 
FIG. 1 is a perspective view of an apparatus according to the 
present invention, portions removed for clarity; 
FIG. 3 is a front view of the removable spacecraft thruster 60 
panel with clamping device for the portable airlock; 
FIG. 3 is a sectional view taken along line 3-3 of FIG. 2 
sho\nling the hruster panel fastener bolt; 
FIG. 4 is an edge view of the thruster panel and wall mount- 
ing .ring at a fastener bolt location; and 
FIG. 5 is partial section view of the portable airlock mount- 65 
ing ring send clamp device, on the spacecraft wall. 
DESCNmION The TEHE PWFERRED EMBODWENT 
Wefemg to the drawings, and in particular to FIG. 1 70 
wherein is iIiustrawd a gortable airlock 11 functionally related 
to the outer wall 13 of a spawcraft at a control thruster 15 lo- 
cation. The outer wall 13 has a circular opening 17 adapted to 
be sealed by a panel assembly 19 having the thrusters 15 
mounted on the outerside. As illustrated, the panel 19 is being 75  
removed from the wall 13 of the spacecraft lanee the Interrev (4 
a portable airlock 8.1 as if an astronaut had enwrted Rss hand\ 
and arms into the flexible space suit-type g8ovc.. 21, 22 a\- 
sociated with the airlock X B and grasped the pane: haredlc 23 
A replacement panel I8 is also available w~thraz thc airlock en- 
closure. 
As is indicated best by FIGS. 3 md 5 ,  the thrustel panel 19 
has an annular edge groove 25 with a sealrng 0-snng member 
27 making a positlve seal against a mounkrng nng 29 surround- 
ing the circular opening 17. A plurality of fastermczr, 31 are 
evenly spaced about the circumference of the panel 19 and 
are adapted to securely hold the panel 89 nn poh~!lcan against 
the mounting ring 29 and to be easily manrpenlsted to releaw 
the panel 19 when desired. 
Tihe fasteners 31 are pivocally secured to the rnomalng nng 
29 by a retaining plate 33 secured the mountnng rung Range 35 
The fasteners 33 fit into matching edge recesss 3 ° F  and 31 on 
the thruster panel 19 and mounting rang 29, respc?eveBy and 
are tightened by individual thumbscrew., 39 of f,utenen 31 
which act throu* nuts 41 held in posltlon by $hie setasnrwg 
plates 33. A particular fastener 31 may be keyed by color o r  
otherwise to a particular panel groove 27 to assbss: the proper 
orientation of the panel 19. 
A clamping device for the p m b l e  atriwk 11 as awwscliated 
with the inner surface of the spacecraft wall 183 surrounding 
the panel mounting ring 29. A first circular memks 43 (sce 
FIG. 5) having a substantial L-shaped cross siectno.a^ s 1s wcurea 
to the inner wall 13 of the spacecraft, whnch nw the present rn- 
stance is shown in FIG. 5 as be~ng provided wth  a relnforcsng 
material $5. The first circular member 43 has an up tand~ng  
portion 47 foming a flange which has a %ubsbnt~ally verkacdi 
flat edge surface. The upstanding porPlon 47 ss thnnner at the 
top than at the base so as to form an outwardly slop~ng surface 
opposite the flat edge. 
The airlock enclosure I B has as lndicilaed by FIGS 1 and 5 
circular opening in its rear panel 49, and .iecured adjacent thc 
edge defined by the opening, or integral therewath, ns a second 
member 51 similar to the first member 43 Ths second 
member 51 also has an upstanding flange 53 weth d flit edge 
surface adapted to fit against the flat edge rucfaec 06 IUac first 
member 43. The second member 51, however, h & ~  an annular 
groove 55 within its fiat edge surface wrth an 0 - r n g  seal~qg 
member adapted to be pressed agalnbt the firkt member 43 
and form an airtight seal. 
The first and second members 43 and 51 an: placed nre 
abutting position and a V-shaped clamp 97 as adapted to fit 
over both upsmdlng po13ions 57 and 53 to securely lock ehcm 
together. 'l%e clamp structure 57 as ~IEustrated ba t  n-r FIGS i 
and 2 is composed of lower and upper arc sestrons 59 and 60 
joined together at their ends by a pair of adjustable COUPUI  ngs 
The ends of each arc section 59 md 60 have a cylandsncai bdr 
nut 63, 65 which is part of the djusQbI.2 coughng bsid by 2 
metal piece 66 secured to the outer edge of the sectnon and 
bent back over the bar 63, 65 and secured to etse&T On cach 
side of the member 43, a threaded rod (4, 67 extends dowr 
from above and is screwed throu& adjacent bas nuts 63 65 ob 
the arc segments 59,66) so a turntng of the rod &Iv 67 in o w  
direction will draw the adjacent nuts 63, 69 together and 
tighten the clarnp 57 on the upstanding p f i m n s  57" 93 (FIG 
5) of the two piece mounting ring 43,51 The a d s  6467 (ad- 
jacent their u p p r  end and nuts are right handed kfnrsdcd aces 
rods 64, 67 adjacent then- lower end snd nuts 6% arc left 
handed threaded. 
Each rod @,ti7 may Rave flexible coupiang 68, 69, 70,71 
to prevent any alignment problems. The upper ends of the 
rods 64,67 are fastened to the inner suufaaee d the spacecraf? 
wail 13 by fixed bearings 72,73. The rignt rod 64 ancludes w 
actuator 76 which 1s geared to the rCKd The r o d ~ o n d  mesq c- 
ment of the right rod 64 is transmined to the ieR rod 67 bv 2.1 
endless chain 78 extending over SprOCMef wheels 81, A2 
secured to the upper ends of the rods 67, Mi iAd-odgk, i" 
should be apparent, that the left rod 67 c o ~ i d  a140 hatit 
separate actuator drive. 
3,572,610 
3 4 
The lower ends of the rods 67, 64 are heid in position by a wall of said spacecraft having an opening extending from 
sprhgs 84, 85. Each spring M, 85 is secured at one end to a the outside 'to the interior; 
raked mount 8T 88 and extends to a rod 67, 64 where it is a panel adaped to close and seal said spacecraft owning. 
secured by a loosely fitting loop so as to not interfere with the said panel having a thruster system on its exterior surface; 
:.oation of the rod 64,6?. 5 means for removably securing said panel to said spacecraft 
TAc upper :mc segment 60 of the V-shaped clamp 57 is sup- wall in a manner to close said opening; 
ported from the inner surface of the spacecraft wall by a a portable irlock enclosure having an owning in its rear 
spring 91. The spring 91 is under a slight tension and extends wall, said opening being larger than said panel; 
from a wai! nrillsr? 92 io a Lug 93 on the upper surface of the means for removably sealing the rear wall of said enclosure 
segment 60. i'*il~so7 t?ie !uwer sqment 59 is supported from the 10 to said spacecraft wall with the opening in the rear wall of 
m c r  surfzx ofthc spacecraft wW1 by a lower spring 95 under the encPousure extending about said panel; and 
,I siight tension and eic~ending from a wall mount 96 to a lower said portable airlock enclosure having space suit type gloves 
:ug 97. extending into its interior and sealed to the enclosure so 
The portable airjock 81, as shown by FIG. 1, has a window an operator may insert his arms therein and mmually 
212 in an upper front panel of its enclosure whereby an as- I 5  remove said thruster panel. 
wonam may view the thruster panel 19. Also extending from 2. The combination as defined by claim 1 wherein said 
 he iower front pmel are two flexible gloves 21, 22 of the means for removably sealing the rear wall of airlock enclou- 
space wit ty;i9e which have a stretching as well as flexing abili- sure to the surface of the spacecraft wall, comprises: 
1.j. The astronaut may at times have his arm thrust into the a first member secured to the interior surface of said 
g?csves 21, 22 kycnd  his elbows, and at other times he will 20 spacecraft wall and extending about said owning; 
:each only slightly past his wrists. a second member secured to the outer surface of the rear 
If the thruster w m b i y  15 is of the type having umbilical wall of said airlock and extending a b u t  the opening 
connection for pphopellalnt feed and control lines, a quick therein; and 
dixonnect (not shown) could be placed oubide the a clamp means for grasping said first and second members 
spacecrafi 1to ensure that propellanb are excluded from the 25 in sealing relationship. 
spaceer& interior. For e e  of operation the umbilical could 3. The combination as defined by claim 2 wherein: 
x ddes3p.ed fie autumatically connect or disconnect when the said first and second members each have an upsunding por- 
panel assembly 19 is removed. tion abutting each other; 
,Mso, whih. is not illustpa@d, the thruster panel 19 should said clamp means having a band member with a receptacle 
have a presslire release valve at a suitable location evacuate 30 adapted to receive the portions said first 
ibe airlock enclosure :! 1 when it is in position and an internally and second member; 
operated at suitable location to allow repressurization sai"fand memkr consisting of at least two segmenbjoined 
,&cr the new; panel 18 is in wition. together with an adjustable means adapted to draw the 
W11iI.e the enclosure 11 has been described with the use of band tightly about the upstanding portions of said first 
space suit-type gioves 211,22 it is also contemplated to provide 35 and second members. 
~"cra-ole manlpulatom wthin khe enclosure 11 which could be 4. T'he combination as defined by clam 3 wherein sad ad- 
operaled by 2xterna.l controls. justable means for the two segments Include 
Oovlously m a y  md~ficahons and variations of the present two pa"S of nuts, each nut secured 30 an end of a xgmena, 
nsieaaton me possible an light of the above teachings. It IS, and 
:hcr,c%efo~> to und@rskmd that wthln the scope of the ap- 40 a pair of threaded rods, each rod acting through a par  of ad- 
mnded c8a1ins the nnwntaon may be practiced other than as jacent nuts on contiguous s p e n t  ends 
spea:nfical'y clarned 5 The combinarlon as defined by clam 4 rncluding. 
9s!fc clam means rotatably mountrng sad  reds to the Intenor surface 
1 of sad  spacecraft, and 
la a spac,s;ecs& hauang an attitude control thruster control 45 means For gearing two rods together 
eptern, the amprovement comprising. 


Thruster maintenance system Patent

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