apollo experience report development of the extravehicular mobility unit

8/8/2019 Apollo Experience Report Development of the Extravehicular Mobility Unit

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C A L N O T E NASA TN 0-8093

MOI000nzcac/)4z c

-OF THE

UNIT

C. Lutz, Hurley L. Stutesmun,A. Carson, und Jumes W. McBdrron IIB. Johnson SpaceTexas 77058

A T I O N A L A E R O N A U T I C S A N D S P A C E

Center

ADM INIS TRA TION WA SHI NGT ON, D. C. NOVEMBER 1975


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1. Report No.NASA TN D-8093

4. Title and Subtit leI APOLLO EXPERIENCE REPORT2. Government Accession No. 3. Recipient's Catalog No.

DEVELOPMENT O F THE EXTRAVEHICULAR MOBILITY IJNIT7. A u t h o r b )

Charl es C. Lutz, Harley L. Stutesman,Maurice A. Cars on, and James W. McBarro n I19. Performing Organization Name and Address

Lyndon B. Johnson Space CenterHouston, Texas 77058

6. Performing Organization CodeJSC-085978. Performing Organization Report N o.JSC S-440

10. Work Un i t No .914-50-80-01-721 11 . Contract or Grant No.

12 . Sponsoring Agency Name and AddressNational Aeronaut ics and Space AdministrationWashington, D. C. 2054615. Supplementary Notes

16. AbstractThis rep ort des cri bes the development and performance history of the Apollo extravehicularmobility unit and its major subsystems.assembly, the port able life-support system, and the oxygen purge syste m, are defined anddescribed in detail as is the evolutionary pro ces s that culminated in each major subsystemcomponent. Descriptions of ground- support equipment and the qualification testin g pr oc es sfor component hardware are also presented.

The thre e major subsystems, the pre ss ure garment

13. Type of Report and Period CoveredTechnical Note

14 . Sponsoring Agency Code

L 17. Key Words (Suggested by Authork) ) 18. Distr ibution StatementSTAR Subject Category:1 2 (Astronautics, General)

* Environmental Control System* Pressure Garment'Life- Support System'Protecti ve ClothingOxygen Purge System

* Space Suit

19. Security Classif. (of th is repor t ) 20. Securitv Classif. (o f this mpe) 21 . NO . of Paces 77 Price'Unclassified Unclassified 78 $4.75


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APOLLO EXPERIENCEREPORTEDITORIAL COMMITTEE

The material submitted for the Apollo Experience Reports(a series of NASA Technical Notes) w a s reviewed and ap-proved by a NASA Editorial Review Board a t the Lyndon B.Johnson Space Cente r consis ting of the following me mbers:Scott H . Simpkinson (Cha irman), Richard R. Baldwin,James R . Bates, William M. Bland, J r . , Aleck C. Bond,Robert P. Burt, Chri s C. Critzos, John M. Eggleston,E. M . Fields, Donald T. Gregory, Edward B. Hamblett, J r . ,Kenneth F. Hecht, David N . Holman (Editor/Secretary),and Carl R . H u s s . The prime reviewer for this reportwas Donald T. Gregory.


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CONTENTS

SectionSUMMARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .APOLLO EMU FLIGHT HISTORY . . . . . . . . . . . . . . . . . . . . . . . .PRESSURE GARMENT ASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . .

Apollo 11 PGA Configuration . . . . . . . . . . . . . . . . . . . . . . . . .Evolution of the PGA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Communications Carrier Assembly . . . . . . . . . . . . . . . . . . . . . .Bioinstrumentation System . . . . . . . . . . . . . . . . . . . . . . . . . .

DESCRIPTION O F THE PLSS AND THE OPS . . . . . . . . . . . . . . . . . .Apollo 11 PLSS Configuration . . . . . . . . . . . . . . . . . . . . . . . . .Apollo 11OPS Configuration . . . . . . . . . . . . . . . . . . . . . . . . . .Apollo 15 PLSS and OPS Configurations . . . . . . . . . . . . . . . . . . . .Evolution of the PLSS and OPS . . . . . . . . . . . . . . . . . . . . . . . .QUALIFICATION TESTING . . . . . . . . . . . . . . . . . . . . . . . . . . . .ThePGA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .The PLSS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .TheEMU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

CREW SUPPORT EQUIPMENT . . . . . . . . . . . . . . . . . . . . . . . . . .Ventilators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Mockups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Pad Emergency Air Pa ck . . . . . . . . . . . . . . . . . . . . . . . . . . .

CONCLUDING REMARKS . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

iii

Page112782229303435424345596062646666676869


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TABLES

PageableII1I11

IVVVIVI1

APOLLO EMU EVA DATA. . . . . . . . . . . . . . . . . . . . . . . . 67RESSURE GARMENT ASSEMBLY CHARACTERISTICS . . . . . . . .

PRESSURE RELIEF VALVE AND PURGE VALVECHARACTERISTICS 18. . . . . . . . . . . . . . . . . . . . . . . .18IQUID-COOLING GARMENT CHARACTERISTICS . . . . . . . . . .

THERMAL AND OPTICAL PROPERTIES OF THE LEVA . . . . . . . 20PORTABLE LIFE-SUPPORT SYSTEM CONFIGURATIONS. . . . . . . 46SPECIFICATION REQUIREMENTS FOR THE PORTABLE 47IFE-SUPPORT SYSTEM . . . . . . . . . . . . . . . . . . . . . .

FIGURES

Figure1 Apollo 11 to 14 EMU . . . . . . . . . . . . . . . . . . . . . . . . . . .2 Apollo 11 PLSS oxygen supply pr es su re prof ile fo r thecommander . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34

Apollo 11 PLSS battery curr ent profile fo r the commanderApollo 11 PLSS sublimator gas outlet tempe ratu re profile for

. . . . . .the commander. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5 Apollo 11 PLSS LCG inlet temperature profile for thecommander . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6 Apollo 11 PLSS feedwater pres sur e profile fo r the commander . . . .7 Apollo 11 PLSS LCG water delta temperature profile for thecommander . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8 Intravehicular press ure garment assembly . . . . . . . . . . . . . . .9 Extravehicular pre ssu re garment assembly . . . . . . . . . . . . . .10 Extravehicular t ors o lim b suit asse mbly . . . . . . . . . . . . . . . .

Page2

44

4

44

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Figure111213141 5161718192021

PageTorso limb suit assembly liner . . . . . . . . . . . . . . . . . . . . . 9Ventilation system and ventilation flow diagram of the EV TLSA . . . 11Intravehicular torso limb suit assembly . . . . . . . . . . . . . . . . 11Pr es su re helmet and helmet attaching neckring . . . . . . . . . . . . 11Pressure gloves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11Material cr os s section fo r EV glove . . . . . . . . . . . . . . . . . . 13Intravehicular cover laye r . . . . . . . . . . . . . . . . . . . . . . . 13Lunar integrated ther mal micrometeoroid garment . . . . . . . . . . 14Material cro ss section fcr ITMG (Apollo 10 to 14 missions) 14. . . .G a s connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15Liquid-cooling garment multiple water connector(a) Front view 15

1522 The PGA ele ctrica l harness . . . . . . . . . . . . . . . . . . . . . . . 1523 Neck dam with lanyard . . . . . . . . . . . . . . . . . . . . . . . . . 1 524

. . . . . . . . . . . . . . . . . . . . . . . . . . . . .(b) Rearview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Apollo 9 to 12 single-flow purge valve(a) Purge mode 17(b) Unactivated 17

17176 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177 Lunar boot

28 21

. . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . .25 Apollo 14 o 1 7 dual-flow purge valve . . . . . . . . . . . . . . . . .

Liquid-cooling garment and coolant system . . . . . . . . . . . . . . .Lunar extravehicu lar visor as sembly (Apollo 13 o 17) . . . . . . . . .

29 Constant wear garment . . . . . . . . . . . . . . . . . . . . . . . . . 2130 Waste management systems

2121(a) Fecal containment subsystem . . . . . . . . . . . . . . . . . . .(b) Urine collection and tra ns fe r assembly . . . . . . . . . . . . . .V


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Figure Page2931

3 1 Communications carrier . . . . . . . . . . . . . . . . . . . . . . . .3 23 3

Bioinstrumentation sys tem . . . . . . . . . . . . . . . . . . . . . .Portable life- support syst em

3 43 5(a) Component assembly . . . . . . . . . . . . . . . . . . . . . . .(b) Schematic dia gra m . . . . . . . . . . . . . . . . . . . . . . . .Oxygen ventilating ci rc ui t schema tic . . . . . . . . . . . . . . . . . 36

373 4353 63738394 0414 2

Diagram of the pr im ary oxygen subsystem . . . . . . . . . . . . . .Liquid transport loop schematic . . . . . . . . . . . . . . . . . . . . 38

40chematic of the PLSS feedwater loop . . . . . . . . . . . . . . . . .Extravehicular communications system for EVC 1 . . . . . . . . . . 40Extravehicular communications system for EVC 2 . . . . . . . . . . 41Remote control unit . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2Oxygen purge system components . . . . . . . . . . . . . . . . . . . 4 2Oxygen purge system

434 4(a) Purg e mode . . . . . . . . . . . . . . . . . . . . . . . . . . . .(b) Schematic dia gra m . . . . . . . . . . . . . . . . . . . . . . . . .Early Apollo PLSS expendables duration (Apollo 9 to 1 4missions) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3 4 5

4 4 Extended Apollo PLSS expendables duration (Apollo 1 5 to17 missions) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 5495

4 6Sectional view of the sub limator . . . . . . . . . . . . . . . . . . . .The LiOH cartridge

515151(a) Canister and reservoir assembly . . . . . . . . . . . . . . . . .(b) Can iste r flow diag ram . . . . . . . . . . . . . . . . . . . . . . .(c) Cartridge . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Extravehicular communications syst em pict oria ldiagram : dual- dual . . . . . . . . . . . . . . . . . . . . . . . . .7 57

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Figure Page48 Extravehicular communications system pictorial diagram :. . . . . . . . . . . . . . . . . . . . . . . . . . . .ual- secondary 5849 Extravehicular communications system pictorial diagram :secondary-p imary . . . . . . . . . . . . . . . . . . . . . . . . . . 5950 Portable oxygen ventilator . . . . . . . . . . . . . . . . . . . . . . . 6751 Cryogenic pack . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6752 Pad emergency air pack . . . . . . . . . . . . . . . . . . . . . . . . . 68

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ACRONYMSAMBSLSSCDRCMCMPCSMCWGECGECSEM1EMUEOSEVEVAEVCEVCSEVVAFCSFMITMGIVIVC LJSCLCG

amplitude modulated

buddy secondary life-support systemcommandercommand modulecommand module pilotcommand and servic e moduleconstant wear garme ntelectrocardiographenvironmental control s yste melectromagnetic interfere nceextravehicular mobility unitemergency oxygen syste mextravehicularextravehicular activityextravehicular communicatorextravehicular communications systemextravehicular viso r assemblyfecal containment subsystemfrequency modulatedintegrated thermal micrometeoroid garmentintravehicularintravehicular cover layerLyndon B. Johnson Space Centerliquid- cooling. ga rment

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LEVALMLMPLOXLRVMCCMSCOPSPCVPEAPP G APLSSPOVPTTPVCRCUsscSIT LSAT/RUCTAvcovoxW M SZ P N

lunar extravehicular viso r assemblylunar modulelunar module pilotliquid oxygenlunar roving vehicleMission Control Center.Manned Spacecraft Centeroxygen purge systempre ssu re control valvepad emergency air packpressure garment assemblyport able life-support systemportable oxygen ventilatorpush to talkpolyvinyl chloriderem ote control unitspac e suit communicationsSystzme International d'Unit&tors o limb suit assemblyt ransmi ter / r eceiverurin e collection and tran sfer assemblyvoltage-controlled oscillatorvoice-operated transmitterwaste management systemimpedance pneumograph


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APOLLO EXPERIENCE REPORTDEVELOPMENT OF THE EXTRAVEHICULAR M OB 1L l T Y U N I T

By C h a r l e s C . L u t z , H a r l e y L . S t u te s m a n , M a u r i c e A . C a r s o n ,a n d J a m es W . M c B a r r o n IIL y n d o n B . J o h n s o n Space C e n t e r

S U M M A R YThe extravehicular mobility unit was developed to provide the Apollo crewmanwith a life-support sys tem that would enable him to per form useful work t as ks in thefree-space environment or on the lunar surface. The syst em could function independ-ently fo r periods of up to 8 hours, o r it could operate with the environmental controlsy st em s of the command module o r the lunar module to provide life support duringplanned or contingency cabin depressurization . Technology fro m the Gemini Progr amw a s incorporated wherever possible i n the design of the Apollo ext ravehicular mobil-ity unit. The evolut ion of the extravehicular mobility unit and the development andtesting prog ram s for the major subsystems of the unit are discussed in this report.Operating pa ra me te rs and the in-flight performance of the unit ar e also discuss ed.

I NTRO DUCTI O NThi s rep or t t ra ce s the history of the Apollo extravehicular mobility unit (EMU)worn by crewme n on the lunar surfa ce. The EMU consi sts of t hree major s ubsys tems ,the pre ssu re garment assembly ( P G A ) , the portable life-support system (PLSS), andthe oxygen purge syst em (OPS). The configuration of these subsystems as used on theApollo 11 mission is described in detail in t h i s report. The emlutionary proce ss thatculminated i n the EMU configuration is also presented, and each major subsystem orcomponent is described from its initial concept to i t s pre sen t design, with part icula r

emphasis on the rea son s fo r the changes. Also included in this repor t a r e a discus-sion of the major te st p rograms conducted to qualify the sys tem fo r flight usage and asummary of the actual in-flight performance. ~

A s an aid to the re ad er , where nece ssary the original units of meas,ure havebeen conver ted to the equivalent value in the Syst;me International d'Unites (SI). TheSI units a r e written first, and the original units ar e written parenthetically therea fter.


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APOLLO EMU F L IG H T H I STORYThe following information pertains toth e in-flight usage of the PGA, the PLSS,and the OPS. The importance of the thr ee

ma jo r subsys tems of the EMU (fig. 1) in-cre ase d with t h e complexity of each suc-ceeding flight and the demands of eachextravehicular activity (EVA) period.The Apollo 7 o 10 missions wereplanned to demonstrate the capability of allflight hardware to operate in space beforethe actual luna r landing. Because extr a-vehicular activities were not scheduled fo rthe Apollo 7 and 8 flights, the only subsys-tem of the EMU onboard the spacec ra ft w as

the PGA. The pri mar y purposes for usingthe P G A on these flights were to serve as abackup to the command module (CM) pres-sure and the environmental control system(ECS) and to protec t the crewmen from

Oxygen purge systemPLSS support straps

Lunar module restraintand tether attachmentsIntegrated therma lmicrometeoroid garmentUrinecollection

Figure 1.- Apollo 11 to 14 EMU.

noise, vibration, et cet era , during launch and reen try. The performa nce of the PGAwas satisfactory, and each flightcrew reported that PGA ventilation w a s adequate dur-ing the orbita l phase of these missions . Doffing and donning were found to be mucheasier at zer o g than at one g and crea ted no prob lems f or the crewmen.A s a re su lt of knowledge gained during the Apollo 7 flight and because of someproblems encountered, a few minor design changes were made in the PG A before theApollo 8 mission. Because of head colds and sinus pro ble ms, the Apollo 7 crewmendecided to make the Earth reentry with helmets and gloves removed to provide a meansof clearing the sinus and inn er- ear cavi ties (Valsalva maneuver) . Because it w a sdesi rabl e to have the complete P G A donned during thi s cri tic al phase of the flight, adevice was incorporated on Apollo 8 and subsequent flight helmets to allow the Valsalvamaneuver to be accomplished without remova l of the helmet or use of the hands. Be-cause the Apollo 8 mission objective w a s to ci rcl e the Moon and retu rn to Eart h andbecause no EVA was required, all three crewmen wore the intravehicular (IV) config-uration of the P G A .The first use of the complete EMU under flight conditions w a s accomplished dur-

ing the Apollo 9 mission. The objective of thi s mission w a s to check out and test thelunar module (LM) ascen t and descent s tag es, including the main and attitude propul-sion sys tems; the ECS; and the LM/CM undocking/docking procedures. The Apollo 9mission was also importan t fo r EVA evaluat ion because some of the LM-to-CM contin-gency transfer procedures w ere to be performed . The lunar module pilot (LMP) in theEMU configuration opened the si de hatch of the LM and eg re ss ed to si mul ate the contin-gency tra nsfer , a simulation that laste d f or approximately 40 minutes. During the LMP

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EVA, the command module pilot (CMP), while connected to the CM ECS, opened the CMside hatch and maneuvered partially inandout of the hatch sev era l tim es, retr ievi ng the rmalsam ple s and taking photographs. Both crewmen reported that they were comfortab leand that they experienced no visual problems with the extravehicular vi sor assembl y(EVVA). The CMP wore one extravehicular (EV) glove and one IV pre ssu re glove; theI V pr es su re glove (worn for sample r etrie val) became warm but not uncomfortable.The LMP ing re ss ed the LM af te r completion of the EVA and doffed the PLSS,the OPS, and the EVVA with no problem s. A t that time, the PLSS w a s recharged inthe LM cabin for pos sible contingency re us e and for demons tration of the feasibility ofthi s operation under actual flight conditions. The rec ha rge w a s completed with noproblems.Each Apollo 9 crewman wore his PG A fo r approximately 52 hours ; most of th istime was spent i n the helmet-and-glove-off o r ventilation mode. For approximately

47 minutes of the flight, the PGA's were pres suri zed to 26 kN/m (3.75 psia).2

The Apollo 10 mission was s im il ar to the Apollo 7 and 8 missions in that the EMUwas not used for EV activities, and the PGA was used only as a backup to the CM ECS.The perfo rman ce of the P G A w a s satisfactory.The Apollo 11 mission w a s the first mission on which the EMU was exposed tothe luna r environment, fo r which it had been designed and tested. A ll as pe ct s of EMUoperation demonstrated during testing and on previous flights were proved on the lunarsurface. Typical telemetry data received from the lunar sur face ar e presented infigures 2 to 7. An evalua tion of EMU performance fo r the Apollo 11mission follows.No significant prob lems were noted at LM eg re ss . Both crewmen stated that theywere comfortable while waiting for t he cabin to depr ess uri ze, even though the'liquid-cooling garm ent (LCG) inle t temperatu re exceeded 305K (90' F) before PLSS sublimat orstar tup. No thermal changes were noted at egress. The cr ew stat ed that the PLSS/OPSwas thermally quite comfortable and that the mass w a s not objectionable.The maximum range trav erse d on the lunar surf ace was approximately 60 meters .One crewman commented that the tr av er se left him a little tire d. However, this fa-tigue occurr ed toward the end of the EVA, and the crewman had not rest ed before theEVA.Mobility and balance in the EMU were sufficient to allow stable movement whileperformin g lunar sur face tasks. The LMP demonstrated the capability to.walk, run,

change di rec tion while running, and stop movement without difficulty. No therma lproblems occurred during the EVA; however, the commander's hands sweated insidethe EV gloves. Because the commander (CDR) did not wea r comfort gloves, his handstended to slip insid e the EV gloves; consequently, th er e w a s a loss in his dexterity andability to handle objects.

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8280 -.- (1200),O 6900-"E clml5 5520

Start egresse (60012 2760- L i t ressure0 integrity check Start ingress Start cabinJ 14aUUI repressurnization0 I I 1 1 I

O-1 0 1 2 3 4Elapsed time, hrFigure 2.- Apollo 11 PLSS oxygen sup-ply pre ssure profile for the com-m ander.

Fan off1 pumD o ff8 rr F a n P o i m ponioxygen on4 6< Start cabin depressurizatione r Hatch open

2. r Start cabin repressurization5 -2 -1 -0 1 2 3 4

=Power on I I IElapsed time . hr

Figure 3.- Apollo 11 PLSS battery cur-re nt profile f or the commander.

305

i 2 9 4 I"Start inaress-J $art egress - +

Shut o ffE (701 I sublimatorStart cabinrepressurization

sublimator2 283.E (501D

(401-1 0 1 2 J3Elapsed time, hr

Figure 4 . - Apollo 11 PLSS sublimatorgas outlet temperature prof ile fo r thecommander.

4

30 5To maximum5

--I

L t a r t gress L t a r t~ ~ ; ~ e s s J cabin:: 50) repressuri-zation278 I I I I140)-1 0 1 2 3Elapsedtime. h rFigure 5.- Apollo 11 PLSS LCG inlettemperatur e profile for the com-mander.

Start cabin1 !depressurization

c ublimator)L ratch openistart_ (51-

13Elapsed time, hr

Figure 6. - Apollo 11 PLSS feedwate rpre ss ure profile for the com-mander.The LCG cooling was adequate, al-though the recorded te mper atur es weremuch higher ( warmer) fo r the CDR thanfo r the LMP.lates with previous ch ambe r experience,

which indicated that the CDR pref er re dto maintain a war mer body te mperaturethan did the LMP. This par amete r iscontrolled by the cre wma n to mee t hiscomfort requirements.missi on that had two EVA per iod s,crewmen spent approximately 4 hours

This difference c orre -

The Apollo 1 2 mission was the firstBoth


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and the EMU's performed satisfactorily.charge of each PLSS was performed.No problems w ere noted during the

(12)5.6- 110)4. 4

Because of the additional EVA, a re-YY-

The Apollo 15 mis sion a lso included an EVA during the re tu rn to Earth , i n whichthe CMP egr ess ed the CM to retr ieve a film package f ro m outside the sp acecra ft. Apr es su re cont rol valve (PCV) wa s used i n conjunction with a n umbilical supplying oxy-gen fr om the CM. The'OPS was used as a backup system and was worn behind theCMP's helmet.

Start cabin repressurizationShut of f sublimator

-

The Apollo 16 and 1 7 missions were virtually the sa me in scope a s the Apollo 1 5miss ion , with thr ee lunar sur fa ce EVA's and one CM EVA on each mission . The long-est EVA of the Apollo Program was the Apollo 17 second lunar surf ace EVA, whichlasted 7 hours 37 minutes. A summary of Apollo EMU EVA data is presented intable I.

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TABLE 1. - APOLLO EMU EVA DATA

EVA time, hr:minDate Type of EVA Crewman Standup UmbilicalMission

Apollo 11Apollo 12

Apollo 14

Free Cumulativea~

1:34

7:lOMar. 1969 Earth orbitalJul y 1969 02:4802:40

_ _ _ _unar surfa ce CDRLM PLunar sur face (EVA 1) CDR

_ _ - _- - - -LMP _ _ - __ _ _ _unar surf ace (EVA 2) CDRLMP _ - - -

Lunar sur face (EVA 1) CDR - - _ _LM P - - _ __ - _ -unar surf ace (EVA 2) CDRLMP - - - -

04:OO04:OO 22:42ov. 1969

03:4603:4604:4804:4804:3504:35- -

Jan. 1971 41:28

July 1971 Lunar surfa ce 1 CDR 1 00:33 I - - 80 :27Lunar surface (EVA 1) - - 06:3306:33

07:1207:1204: 5004:50

Lunar s urfac e (EVA 2) CDRLMP

I E%unar surface (EVA 3)Transearth CMPLrMP 00:3800:38

Apr. 1972 Lunar sur face (EVA 1) 1 CDR _ _LMP 07: l l07 : l l 123:41pollo 1 6Lunar sur face (EVA 2) I CDR - -LMP 07:2307:23Lunar s urf ace (EVA 3) 1 CDRLM P 05:4005:40Transearth CMP -- 01:23LMP 01:23 - -

- - _ -unar sur fac e (EVA 1) CDRLMP - _ _ - 07:1207:12 17O:Olec. 1972pollo 17I Lunar sur face (EVA 2) 1 CDRLMP 07:3707:37~~ --T E% :: I - _ _unar su rf ac e (EVA 3) 07:1507:15Transearth 01:06

Totals I 04:27 I 03:07 162:27 - -aRepre sents man- hours.

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PRESSURE GARMENT ASSEMBLYThe PGA is an anthropomorphic protective assembly that encloses the crewmanin a pres suri zed environment and permit s performance of mission tasks in a vacuumambient pr es su re condition. The PG A is worn by the crewman during I V spacecraft

operations and during EV free-s pace operations and lunar surface explorations.The PGA is designed to be worn for a contingency CM transearth return of 115

hours at a regulated pressu re of 26 * 1 . 7 kN/m (3.75 f 0.25 psid) in conjunctionwith either the constant wear garment (CWG) o r the LCG. The operating characte r-is ti cs of the P G A are listed in table 11. A detailed desc rip tion of the A7L P G A ' s usedfor the Apollo 11 lunar landing and surface exploration mission follows.2

TABLE 11 - PRESSURE GARMENT ASSEMBLY CHARACTERISTICS

Characteris t ic I Value II PGA with ITMGa 1 PGA with I V cover layer II--- 1 I~Weight, kg (lb) . . . . . . . . . . . . . . . . . . . . . . . . . .Operational temperature limitations,K ( " F ) . . . . . . . . . . . . . . . . . . . . . . . . .2Leak rat e at 25. 5 kN/m (3. 7 psid)m a . , s $c /m in ( l b/ hr ) . . . . . . . . . . . . . . . . . . . . .2Operating pre ssur e, kN/m (psid) . . . . . . . . . . .2Structural pres sure , kN/m (psid) . . . . . . . . . . . . . . . .Proof pr ess ur e, kN/m (psid) . . . . . . . . . . . . . . . .Wlrst pre ssur e, kN/m (psid) . . . . . . . . . . . . . . . . . .Pr es sur e drop, kN/m2 (in. of H20)

22

3 2At 0.34 m /min (12 acf m), 24 kN/m(3. 5 psia), 283 K (50"F) , with inlet diverter valveopen (Iv position) . . . . . . . . . . . . . . . . . . . . .3 2

(3.9 psia), 298 K (77" F), with inletdiverter valve closed (E V position)2

At 0.1 7 m /mi n (6 acfm), 27 kN/m . . . . . . . . . . .Pr es su re gage range, kN/m (psid) . . . . . . . . . . . . . . .

aIntegrated thermal micrometeoroid garment.bSpacecraft w al l .

19.69 (43.42)

4394 (t250)

180.00 (0.0315)26 z 1. 7 (3. 75 I 0. 25)

41 (6. 00)55 (8. 00)69 (10.00)

1.17 (4.70)

0.45 (1.80)1 7 to 4 1 (2 . 5 to 6 . 0 )

15. 48 (34. 13)

b244 to t 339 (-20 t o t 150)

180.00 (0.0315)26 + 1.7 (3. 75 . 0. 25)

41 (6.00)55 (8.00)

69 (10.00)

1. 17 (4. 70)

No t applicable1 7 to 41 (2. 5 to 6.0)

7


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Apollo 11PG A Conf igura t ionTwo configurat ions of the P G A were worn on the Apollo 11mission. The A7L IVPGA shown in f igu re 8 was worn by the CMP. The A7L EV P G A shown i n fig ure 9 wasworn by the CDR and the LMP. The two configurations were s imil ar except that theA7L IV PGA w a s equipped with a lighter weight and l es s bulky IV cover layer (IVCL)and did not include the hardware and control s necessary for EV use.Each A7L PG A (IV and EV) cons isted basica lly of a tor so limb suit assembly(TLSA) with an integrated protective cover la ye r, a pressure helmet, pr essu re gloves,cont rol s, instrumentation , and communication equipment. Additional equipment con-sisting of a lunar extravehicular vis or assembly (LEVA) and lunar boots w a s providedto complete the EV P G A .The TLSA. - The TLSA is that part of the PG A that covers the crewman's entirebody except hi s head and hands. The TLSA's for both P G A configurations a r e basicallythe same , but some differences exist pri mar ily because of different missi on require-ments. The A7L EV P G A TLSA w i l l be descr ibed fully, and only the differences willbe discussed for the A7T, I V PG A configuration.The EV TLSA: The EV TLSA is shown in figure 10. The to rs o portion of theTLSA is custom si zed and the limb portions are graduated in s iz e and adjustable toaccommodate individual crewman l imb lengths. A pressure sealing and restraint slidefast ener cl osure permi ts crewman entry into the TLSA. A lock assembl y is secured tothe restraint assembly to captivate the pressure sealing slider and prevent inadvertentopening.The pressure-containing bladder of the TLSA is a neoprene-coated nylon fabric.Directly over the bladder outer s urf ace is a nylon restraint layer that controls the con-formal shape and provides stru ctu ral support to the bladder. Dipped-rubber convoluted

joints of near-constant volume a r e located at the shoulders, elbows, wr ist s, hips,knees, and ankles to pe rmit joint movement with a minimum expenditure of energy.Restraint cables or cor ds with reinforced attachment points a r e provided to sust ainaxial limb loads during press ur ize d modes of operation and to prevent ballooning ofthe convoluted joints. A biomedical injection patch is built into the right thigh portionof the T L SA to permit a crewman to self-administer a hypodermic injection withoutjeopardizing the gas retention quality of the P G A .The TLSA has an a r m bearing to enhance a r m rotational movements above theelbow. The P G A boot, which is connected to the TLSA, is size d to the individual cr ew-man's foot and has an ankle convolute designed to permi t ankle extension and flexionmovements. A metal heel clip is provided to at tach the boot to the CM couch footpan

fo r leg rest raint during launch and reen try .The innermost layer of the TLSA is a nylon liner (fig. 11)provided for comfortand to facilitate donning. A se ri es of noncollapsible ducts is attached on the innersur face of the neoprene-coated nylon bladder and se rv es as pa rt of the ventilationsystem.

8


19/79

Pressure helmet

Biomedical injection

Figure 8. - Intravehicular pre ssur egarmen t assembly.

omrnunications carrie r

Urine cdlectianand biomedicalinjection access flap

elmet attaching neckringMultiple water connector

Electrical connectorGas connector (in

Gas connector (out1Gas connector (inlet)

LM restraint s connector (outlet)and tether attachments ressure relief valwattachment brack etUrine transfer fitti Clove attaching disconnect

-4iLkM couch restraintFigure 10. - Extravehicular tors o lim b

suit assembly.Communications leadsnap flap

lead passthrough

Biomedical leadpassthrough-

napCommunications ssembly

Urine transfer hosepassthrough

Slide 1fastenerFigure 11.- Torso limb suit assemblyliner.

Figure 9. - Extravehicular pre ssur egarment assembly.

9


20/79

The ventilation s yst em provides fo r two modes of operation, EV and IV . In theEV mode, all inlet gas flow is directed to the helmet for resp irat ion and helmetdefogging. The gas flow then trave ls over the body to the extr emiti es, where returnducting routes the flow to the suit outlet. In the IV mode, the ga s flow is split, withpar t of the gas flow going into a to rs o duct and directly over th e body and the remaininggas going to the helmet. The ventilation sys te m and ventilation flow paths for th e EVTLSA a re shown in figu re 12. Metal brac ket s ar e provided at the upper buckle andlower pulley of the to rso tiedown sy st em fo r attachment of the PLSS re st ra in t s tr ap s.The LM restraint tether attachments are located on each side of the P G A torso at thehip area.Th e IV TLSA: The IV configurat ion of the TLSA (fig. 13) is basically the sameas that for the EV TLSA. The IV TLSA inc orpor ate s Zn a r m assembl y with a netre st ra in t elbow joint because th e added mobility provided by the a r m bearing is notnece ssary for IV operations. The I V ventilation system r equ ire s only one set of inletand outlet gas connectors with only one to rso vent duct, inste ad of two a s used in theEV configuration.The left a r m of the IV TLSA does not incorporate provi sion fo r a pressure reliefvalt e because pressur e relief capability is provided in the CM ECS. Othe r componentsnot included in the IV TLSA ar e the LCG multiple wat er connector and the LM res tr ai ntteth er and PLSS attachment brac kets .Pressure helmet assembly. - The pre ssur e helmet is a detachable, transpar entclo sur e with provisions fo r feeding and drinking and fo r attachment of the LEVA. Thehelmet is made by a special heat-forming pr oc ess fro m high-optical-quality poly-carbonate plastic. The helmet and the ring that attaches it to the TLSA are shown infigur e 14. Th e helmet contains a feedport that allows insertion of a probe foradministering water and contingency food to a crewman wearing the complete PGA ineither the pressurized or unpressurized condition. A synthetic elastomer-fo am vent

pad bonded to the re a r of the helmet shell prov ides a headrest and acts as a ventilationflow manifold directing ga s flow to the or al- nas al area. This flow ca use s an efficientexhaust of carb on dioxide (C0 2) fr om the nasal area to the TLSA through the tors oneck opening.Pres sure gloves. - The pres sur e glove is a flexible, gas-retai ning device thatattaches and locks to the TLSA through a quick-disconnect coupling. Th er e a r e twobasic types of pr es su re gloves, the IV pre ss ur e glove used only for IV operatio ns withthe PGA and the EV glove used d ur ing EVA'S.Th e IV glove assemb ly: The IV glove (fig. 15) is used for IV acti vit ies only.

Under normal conditions, the gloves are donned only when the suit is pressurized. TheIV glove consi sts prim ari ly of a bladder molded fr om a cast of the crewman's hand.Dexterity of the bladder is increased by built-in relief projections located over theknuckle areas. A convoluted section is incorporated in the wri st area to provide omni-directional mobility of the wr ist . The convoluted sect ion is restrained by a syste m ofsliding cables secured to the wr is t disconnect. The glove side wr is t disconnect is themale portion of the wris t disconnect assem bly and ha s a sealed bearing that perm its360" glove rotation. The fin ger le ss glove is a restraint assembly that is cementedonto the bladder at the wri st area and encloses the entire hand except the fing ers and

10


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Note:Helmet e n t ductThe I V PG A has

and left gasconnectors

-Typical cross section d duct LBcmt vent pad

Figure 12 . - Ventilation syste m andventilation f l o w diagram of the EVTLSA.

Figure 13. - Intravehicular torso limbsuit assembly.

Recess channelVent s p a c e r 7 r

Lock subassemblyLock stop

Helmet attaching neckring(suit haln

Figure 14. Pr es su re helmet and helmetattaching neckring.

Wristlet

Ev pressure glove

I V pressure glove Comfort glove

Figure 15. - Pre ss ure gloves.

11


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thumb. A palm restraint str ap is used to minimize the ballooning effect crea te d underpre ssur ize d conditions and to enhance grip control. The convolute cove rs protec t thebladder and the convolute rest ra in t sys tem . The sliding cable- type convolute rest ra in tsys te m accepts the axial load a cr os s the convolute.The EV glove assembly: The EV glove (fig. 15) is a protect ive hand c over that

interfa ces with the TLSA before crewman eg re ss for EV operations. The glove consis tsof a modified IV pr es su re glove cove red by an EV glove shell . The shel l cov er s theent ire hand and has an integral cuff, o r gauntlet, that extends above the w ri st disconnecton the arm a s far as the P G A pres sure gage o r the pressure relief valve. The EVglove shell, a multilayered assembly, provides scuff, abrasion, and thermal protectionfo r the pre ss ur e glove. The mate ria l layup of the EV glove is described in figure 16.A woven metal fabric (Chromel-R) is incorpora ted over the palm and fing ers to provideabra sion protection. The thumb and fingertip shel ls are made of high-strength,silicone-rubber-coated nylon tri cot fo r improved tactility and st rength. A siliconedispersion coating is applied to the palm, around the thumb, and to the inner side ofeach finger to provide incr eas ed gripping char act eri stic s. The oute r cover is conformaland does not apprecia bly les sen the flexibility of the inne r glove. A flap is sewn ontothe back of the glove shell and provides acc es s to the palm res tra int str ap. The flapis opened o r closed by engaging o r disengaging the hook-and-pile fast ene r (V elc ro) tapestri ps. The palm restrai nt stra p can be tightened as necessary to minimize theballooning effect of pressuriz atio n. The she ll assemb ly is secured to the pressu reglove a t the back and palm of the hand by Velcro tape and nea r th e tip of each finge r bytwo anchor st ra ps and neoprene adhesive.

Cotton wristlets a re used to prevent a r m chafing ca used by the PGA wr is t dis -connects when the TLSA is worn without the gloves. Comfort gloves cons truc ted ofnylon tricot are provided fo r wear under either the IV gloves o r the EV gloves. Thecomfort glove facili tat es donning of the pr es su re glove and act s as a perspirationabsorption lay er between the hand and the pr es su re glove bladder.Integrated protective cover l ay er s. - Cover layers are inte grat ed with the TLSAto provide added protec tion to the crewman and to the PGA. The extent of t hi s pro-tec tion depends on the configuration of the PGA and on the environment to which i t willbe exposed. The I V P G A is provided with an IVCL, and the EV PGA is provided witha n integrated therma l micrometeoroid garmen t (ITMG).The IVCL: The IVCL (fig. 17) is a three-la yer overgarment designed to protectthe crewman and the TLSA fr om abras ion. The IVCL is conformal to the TLSA, withmobility relief incorporated into the knee, elbow, shoulder , and hip areas. The coverlayer is composed of th re e la ye rs : an inne r layer of Nomex cloth and two out er la ye rs

of nonflammable Teflon-coated-filament Beta cloth. Additional abrasion la ye rs(const ructed of one thickness of Teflon-coated-filament Beta clo th) a re added to theex te rio r of the suit a t the knee, elbow, and shoulder areas. An abra sio n pad, con-structed of Nomex felt, is attached to the sui t at each shoulder. Additional scuffprotection is provided by Teflon cloth patc hes i n high a brasion areas.Flap ass emb lies provide a cc es s through the IVCL for the entrance closure, thebiomedical injection disk, and the urine collection and tra nsf er ass emb ly (UCTA)connector. These flap assem blie s have identical c ro ss sectio ns to the main body of

the IVCL. The IVCL al so includes a flashlight pocket on the upper rig ht a r m section,

12


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Material Function 1 Function 2 Function 3

Pressure retentionlnsulationlilm/ Thermal

PGA glowAluminized Mylar'(7 layers)Nonwoven Dacron'(6 layers)Teflon-coated fila-ment Beta cloth

Thermal,PGA gloveAluminized Mylar'(7 layers)Nonwoven Dacron'(6 aprs)Silicone-rubber-coated nylontricot

PGA gloveAluminized Mylar'17 layers)Nonwoven Dacron'(6 ayers)Chromel-R metalfabric

Pressure retentionInsulat ion-1ilm ;hewy1 hermal.Insu lati on spacer section protectionmicrometeoroidpressure reten-I ~ ~ i ~ 0 s 5Nonflammable shell

Gauntlet

micrometeoroidprotectionDressure reten-Insulation spacer 1 Z i i n 1 tion crosssectionncreased tactil ityshellThumbtip and fingertips

Pressure retention 1Insulation f i lm 1 ; 1 hermal,Ins ul ati on spacer section protectionmicrometeoroidDressure reten.tion crosssectiononflammable andabrasion andheat resistant I

Palm. thumb, and fingers'Alternati ng iayers of insula tion and spacer.

Figure 16. - Material cro ss section forEV glove.

Looptape-

L ~ o o pape

Figure 17. - Intravehicular cover layer.and a utility pocket on the upper left thigh section. A l l pocket assemblies are construc-ted of a n oute r layer of Beta cloth over a n inner lay er of Nomex fab ric , and al l a r eheld closed by flameproof Velcro on the flap s.

An IVCL boot cover assembly fits over the TLSA boot and is secured by loop tapelocated around the top and the bottom of the boot. The IVCL boot cover assembly isconstructed of the sa me mate ria ls as the IVCL.The ITMG: The ITMG (fig. 18) is a lightweight multilaminate ass embly designed

to cover and conform to the contours of the TLSA. The la ye rs of mat er ia ls composingthe ITMG provide protection against the thermal and micrometeoroid ha zar dsencountered during the fr ee -spac e and lunar excursions of an Apollo mission. The cros ssection of the ITMG ma ter ia ls is shown in figure 19. For protection against abrasion,an additional exte rnal lay er of Teflon fabr ic is attached to the knee, waist, elbow,and shoulder are as , and a layer of Chromel-R is added on the back under the PLSS,Pock ets a r e provided on the shoulder of each a r m and on the thigh of the leftleg. Thr ee belt loops a r e secured at the bottom of each leg for holding the detachabledata list pocket and t h e rherklist 2nd -ccissws~c)c!E~E. Ar. acti:.e-dcsimeter p ~ e k e tis located under the UCTA connector and biomedical injection acce ss flap.

13


24/79

Entrance tlosureaccess flap PLSS abrasion patches

Tether attachment

Material ~~ Function 1 Function 2Rubbe-coated nylon In ne r line r(ripstop1Aluminized Mylar' Thermal radiation( 5 layersl protection-lNonwouen Dacron" Therm al spacer(4 layersl crosslayer c section

Bmt .

ToI5 0 adjustment strapEntrance closure

UCTA and biomedicalinje cti on access flap

@ L D a t a istwcket

Function 3

Thermal.micrometeoroidprotectioncross sectionAlumin ized Kapton Thermalradiationmarquisette laminate protectionJilmlEeta(2 layersl

Teflon-coated Nonflammable andfilament Beta cloth abrasion protectionTeflon cloth Nonflammable

layerabrasionpatches

'Alternating layers of insula tion and spacer.

Figure 19. - Material cr os s section fo rITMG (Apollo 10 to 14 miss ion s) .Figure 18. - Lunar integrated ther malmicrometeoroid garment.

Access f laps constructed of a thermal- resistant cr os s section of mat eria ls areheld closed by a system of snap fas ten ers and fir e-r esi sta nt Velcro tape. Thes eac ce ss flaps cover the entrance cl osu re and the UCTA connector and biomedical injec-tion area. Thermal protective cov ers provide protection to the pr ess ure relief valveand the PG A press ure gage while permitti ng continuous monitoring of the suit pre ss ure.The ITMG boots cover the PGA boots except fo r the so le and heel. Each bootassembly h a s the sa me cro ss section as the ITMG. A system of loop tape and lacingcor d sec ures the ITMG boots to the P G A boots.at the boot top and around the sol e andheel area. A zipper is provided a t the top of each boot fo r attachment to the leg of theITMG. A Teflon patch encircl ing the ankle is added to each ITMG boot a ssembly toprevent abrasion caused by the lunar boot.The PGA connectors, control s, and instrumentation . - The PGA contains vari ousconnectors, cont rols, and instrumentation nece ssary (1 ) to interface with the spacecraftECS, (2 ) to allow the crewman to make adjust ments for co mfort and safet y, (3) to

allow the crewman to monitor sys tem s tat us, and (4) to inte rface with the PLSS andOPS ( E V PGA only). A l l the oxygen and pre ss ur e i ntegrity co nnectors have positiveredundant locking devices that permi t saf e connection and disconnection by an unas sistedcrewman in a vacuum.Gas connector: Both P G A configurations are provided with an inlet and a n outletga s connector (fig. 20) fo r interfacing with the ventilation loops of the ECS, the PLSS,o r oth er life-supporting syst ems. The E V P G A , however, is provided with two sets:two in let connectors interconnected by a plenum chamber and two outlet connectors

14


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26/79

Multiple water connector: The multiple wate r connector (fig. 21 ) is a dual-pass age ball/lock assembly consisting of a recepta cle, an LCG water connector, a PLSSwater connector, and a plug. The rece ptac le is mounted on the EV P G A and acts a sthe interface between the LCG connector and the PLSS water connector. A protectivein te rnal plug provides P G A pressure integrity after the LCG water connector has beenremoved from the P G A multiple water receptac le.The UCTA connector and hose ins tall ation: The UCTA connector and hose insta l-lation cons ists of a ball/lock connection and a sized length of hose. The connector isflange mounted to the right leg thigh cone and is designed to receive the space craftwaste management umbilical. The hose assembly is attached to the inner connectorand extends t o a male adapter that ma tes with the UCTA connector. The instal lation isdesigned to convey waste from the UCTA to the spac ecra ft waste management sys tem(WMS).Electric al harness and bioharness: The PG A electrical har ness (fig. 2 2 ) has acen tral 61-pin connector fr om which two branches extend. One branch is used toconnect the harn ess to the communications ca rr ie r, and the second, sho rt er branch is

connected to the bioharness. The communications branch includes a 21-pin connector,and the bioinstrumentation branch has a 9-pin connector. Each branch is covered witha Teflon fabric sheath and a Teflon fabr ic cover and is attached to each connector by ametal clamp. The cen tral 61-pin connector is designed to rece ive the ball/lock engage-ment mechanism of the communications and bioinst rumentation umbi lical of the space-craft or the PLSS.Neck dam: A rubber neck dam (fig. 23) engages the helmet attaching ri ng toprevent water from entering the suit during CM water egr ess . A restrain ing lanyardthat snaps onto the P G A is provided.

. The PGA con tro ls consist of two-position ventilation-flow d iver ter valves locatedon the inlet gas connectors, a pr ess ure relief valve, and a detachable, manuallyactivated purge valve (figs. 2 4 and 2 5) used for EV operation with the OPS. Thecharacte ristics of the pressur e relief valve and the purge valve a r e listed in table 111.'The PGA displays consist of a pre ss ur e gage (1 4 to 41 kN/m (2 .0 to 6.0 psid)) mountedon the lower arm.

2

The LCG. - The LCG is worn next to the skin under the PGA during LM acti vit iesand EVA'S. The LCG (fig. 26) is made of nylon spandex knitted ma te rial and providesfor general comfort, perspir ation absorption, and ther mal trans fer between the crew-man's body and the cooling fluid in the ga rment. The garment provides a continuousflow of temperature-cont rolled wat er through a network of polyvinyl chlor ide (PVC)tubing stitched to the inside sur fac e of the open-mesh fa bric garment. A lightweightnylon comfort liner sep ara tes the body fr om the tubing network. Front c losu re is bya slide fastener.

The LCG coolant water fr om the PLSS pas ses through the inlet pas sage of themultiple water connector and circul ate s through the manifold and the tubing network.The LCG can also be supplied with coolant water f ro m the lunar module. The networkof tubing h a s a parallel flow path providing maximum su rfa ce coverage for optimumcooling. Although the LCG has attached, cust om-size d so cks , the soc ks do not

16


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Inner

r linement tabLock tab7housing-

Lock tab

(a) Purge mode.

Outer housing (b). Unactivated.Figure 24. - Apollo 9 to 12 single-flowpurge valve.

Pu ll pin- 1

Ori fice selector cap

Figure 26. - Liquid-cooling garment andcoolant system.Liner andinsulation a s s e m b l y 7

etaining strap assembly

Figure 27,- Lunar boot.

\

Figure 2 5 . - Apollo 14 to 17 dual-flowpurge valve.

17


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TABLE 111. - PRESSURE RELIEF VALVE AND PURGE VALVE CHARACTERISTICS

I 1Weight, kg (lb) . . . . . . . . . . . . . . . . . . .

2Operational pr es su re limi ts, kN/m (psid) . . . .Leak rate, scc/min

2At 26 i 1 .7 kN/m (3.75 i 0.25 psid) . . . . .At 35 kN/m (5.0 psid) before cracking . . . .At 32 kN/m (4.6 psid) af ter res ea t . . . . . .

22

2Cracking pressu re, kN/m (psid) . . . . . . . . .Flow rate, kg/hr (lb/hr)

2At 40.3 kN/m (5.85 psia) . . . . . . . . . . .At 28 kN/m ( 4 . 0 psia) . . . . . . . . . . . . .

I ValueNot applicable

55 (8 .0 )

Not applicable4.04.0

35 to 40 (5.0 to 5.75)

5.53 (12 .2 )Not applicable

Characteristics I Pressure relief valve Purge valve I0. 29 (0. 63)

55 (8 .0 )

4 . 0 INot applicableNot applicableNot applicable

Not applicable3. 62 (8.0) 1

TABLE IV. LIQUID-COOLING GARMENT CHARACTERISTICS

Weight (charged), kg (lb) . . . . . . . . . . . . . .22

Operating pres su re , kN/m (psid) . . . . . . . . .Structu ral pr ess ure , kN/m (psid) . . . . . . . .Proof pr es su re , kN/m (psid) . . . . . . . . . . .Wlrst pr es su re , kN/m (psid) . . . . . . . . . . .Pr es su re drop, kN/m (psi), at 1.8 kg/min(4.0 lb/min) and 294 + 5. 5 K (70" + 10" F)inlet . . . . . . . . . . . . . . . . . . . . . .Leak rate, cm3/hr, at 131 kN/m (19.0 psid)

22

2

2and 280 K (45" F) . . . . . . . . . . . . . . . .

%eluding both halves of connector,

18

2.09 (4. 60)29 to 158 (4.20 to 23.0)

217 + 3 (31. 50 + 0.50)217 * 3 (31.50 + 0.50)

328 (47. 50)

2 2 (3.2)

0.058


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inco rporate the cooling tubes. The coolant water is warmed by heat trans fer from thecrewman's body. The warm wate r re tu rn s to the PLSS through the outlet channel ofthe multiple water connector. The LCG can remove heat at a maximum ra t e of 586watts (2000 Btu/hr) . Cha rac teri stic s of the LCG a r e given in table IV .Lunar boots. - The lunar boots (fig. 27) provide the rmal and abra siv e protectionfor the PG A boots during lunar sur fac e operations. The lunar boots are donned byinserti ng and positioning the P G A boots with the donning st ra ps (located at the toprear of each lunar boot) and engaging the snap st ra p. A st rap that extends ac ro ss theinstep fr om each heel is als o latched to provide a more sec ure fastening. The latch- .ing mechani sm of the s tr ap can be activated by a crewmember wearing EV gloves.Except fo r the so le, the outer la yer of a lunar boot is fabricated from metalChromel-R woven fab ric ; the tongue area, from Teflon-coated Beta cloth. Ribs pro-ject from the bottom of the silicone rubber so le to inc rea se therma l insulation quali-tie s, to provide lat er al rigidity, and to provide traction on the lunar surfa ce.The inner layers (from the Chromel-R fabric inward) consi st of two layers ofalumin ized polymide (Kapton) followed by five lay er s of aluminized perfora ted Mylarseparated by four layers of nonwoven Dacron followed by an inner l ine r of Teflon-coated Beta cloth. Two la ye rs of Nomex fel t i n the sole provided additional ther malinsulation fr om the lunar s urface .The LEVA. - The LEVA (fig. 28) furnishe s visual, the rmal , and mechanicalprotec tion to the crewman's helmet and head. The LEVA is composed of a plasticshell, thre e eyeshades (left, center , and right), and two viso rs. The outer visor,o r Sun vi so r, is made of high -temperature polysulfone pla st ic . The inner visor , o rprotective vis or, is made of ultraviolet-st abilized polycarbonate plasti c. The oute r

visor fi lte rs visible light and reje cts a significant amount of ultrav iolet and infr aredrays. The inner visor fil te rs ultraviolet rays, re jec ts infr are d rays, and, in combi-nation with the Sun visor and pressu re helmet, f orm s an effective thermal ba rri er .The two v is or s i n combination with the helmet protect the c rewme mber fro m micro-meteoroid damage and fro m damage that could res ult i f he fell on the lunar s urfa ce.A hard shell pr otec ts the Sun visor during nonuse periods. The eyeshades a r e adjustedby the crewma n to preven t gl are from obscuring vision during EVA.The Sun visor and eyeshades may be individually positioned anywhere between"full up" a nd "full down, but the protect ive visor is use d in the "full down" positionfo r EV operations. A crewman can attach or detach the LEVA fr om h is helmet withoutthe aid of tools. A latching mechanism allows the lower r im of the LEVA to be tight-

ened and sec ured around the neck are a of the press ure helmet. The mechanism con-si st s of an overcenter latch that locks on the lower r im , dra ws the two s ide s together,and holds them s ecur e. The LEVA/PGA interfa ce collar provides ther mal and dustprotection fo r the neckring. The LEVA thermal and optical prope rtie s a r e listed intable V.The CWG . The CWG (fig. 29) is a cotton fa br ic undergarment worn next to theskin during IV CM operat ion, The CWG provides genera l comfort and pers pira tionabsorpt ion and holds the bioinstrumentation system. In the CM, the CWG is worn underthe P G A .

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TABLE v. - T H E R M A L A N D OPTICAL PROPERTIXS F T H E L E V A

Ultraviolet. Visible, Near infrared,arameter to 0 . 38 0. 3 8 to 0. 7 6 0. 7 6 to 3 .0 Far infrared,from 3 . 0

~~~~

Reflectanceinside, p . . . . . . . .Reflectanceoutside, p o . . . . . .Transmittance, T . . . .Emittance

inside, E . . . . . . . .Emittance

0 ' " ' "utside, F

Ref le ctanceinside, p . . . . . . . .Reflectance

0 ' * . . .Transmittance, T . . . .Emittance

outside, p

inside, E . . . . . . . .1Emittance

0 ' " " 'utside, E

0. 1 4

. 1 4. 1 8

_ __ _

0.01 .

.01

. 9 2

_ __ _

Impact 3 rot e c ive vis0r

0. 1 3

.07

.00_ __ _

Reflectanceinside, p . . . . . . . .Ref le c anc e

0 " " "Transmittance, T . . . .Emittance

outside, p

inside, E . . . . . . . .Emittance

0 ' " ' "utside, E

0 . 0 8

. 0 8

. 0 1_ _- -

0.07

.ll

. 63_ __ _

Sun visor

0. 0 4

. 28

. 1 9

- -

- -

0 . 1 5

.15

. 6 8

- -_ _

0. 50

. 3 7

. 3 7

_ _- -

0. 6 6

. 58

. 1 2

0.07

.07

. 00

. 9 3

. 9 3

0 . 9 0

. 0 5

. 00

.10

. 9 5

0.94

. 0 6.00

. 0 6

. 9 4

20


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Hinge renteryeshade

Latch and catch a s s e m b l y 1

Figure 28. - Lunar extravehicular visorass emb ly (Apollo 13 to 17).6 3

Bioinstrumentation belt attachment

Figur e 29. - Constant wea r garment.

(a) Fecal containment subsystem.

(b) Urine. collection andtran sfer assembly.Figure 30. - Waste management systems.

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Waste management provisions are provided by a f l y opening and a buttock port inthe CWG to allow urination and defecation to the CM WMS without removing the garment .Snaps a r e provided to attach the biobelt, which contains the bioinstrumentat ion.The W M S . Management of body waste when the P G A is donned is accomplishedthrough the fe cal containment subsyste m (FCS) and the UCTA.The FCS: The FCS (fig. 30(a)) consi st s of elas tic underwear with an absorbentliner around the buttock area. This subsystem is worn under the LCG o r CWG t0 allowemergency defecation when the P G A is pressurized, The FCS weighs 0.227 kilogram(0.50 pound) and has a capacity of 1000 cubic cen timet ers of solid s.The UCTA : The UCTA (fig. 30(b)) provides for collection and interme diat e sto rageof a crewman's urine during lift-off, EVA, o r emergency modes when the spacec raft

WMS cannot be used. The UCTA will accept urine at r at es a s high as 30 cm /sec witha maximum st or ed volume of 950 cubic cent imeter s. No manual adjustment or opera-tion by the crewman is requ ired while the UCTA is collecting urine . Pr ess ure rel iefvalves a r e inco rporate d in the ur ine collection bag to prevent exposure of the body topr es su re differe ntials of *249 N/m (* 1 inch of water ) between the collection bag andthe P G A . The valves open automatically as required to increase pr essur e i n the col-lection bag. A flapper check valve prevents r ev er se flow fro m the collection bag tothe ur ina l portion of the UCTA. The store d urine can be tra nsfe rred through the suitwall by hose, when feasible, to the CM o r LM during either pressuri zed or depressur-ized cabin operation.

3

2

The UCTA is worn over the CWG o r the LCG and is connected by hose to theuri ne transf er connector on the PGA. This uri ne transf er connector is a quick-disconnect fitting that is used for the trans fer of u rine fr om the UCTA to the space-craft WMS. A UCTA tra nsf er adapter is provided onboard the CM fo r us e by the c rew-men to dump the UCTA's aft er the P G A ' s have been doffed.

Evolution o f the PG AThe discussion of PG A evolution includes the A5L, A6L, A7L, and A7LB PG Amodels.The A5L PGA model. - The configuration of t he PGA selected fo r use i n theApollo Program resulted from a competitive evaluation of th re e different prototypemodels in 1965. The P G A configuration selected was designated the AX5L PGA andcons isted of a TLSA, IV pressure gloves, and a bubble-shaped helmet. Improvementsand changes identified during the evaluation were incorporated , and the model w a s re-designated th e A5L P G A . Changes inco rporate d into the A5L PGA configuration in-cluded use of a pr es su re sealing clos ure (s imila r to that of the G-4C model Geminispace suit) with reinforcement gusse ts added at each end, us e of Ve lcro to attach theinner liner to permit easy removal for cleaning, addition of lace sizing adjustmentsat the elbow and knee joints, and repositioning of the neckring to provide the co rr ec tcrewman eye-to-heart angle requir ed for launch accelera tion. Antichafing o r anti-abrasio n patches also wer e added on vari ous convolutes and ar e as of the pr es su rebladder at high-wear points.

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The A5L P G A w a s used for design verification testing, crewmember evaluations,and spacecraft systems configuration reviews. U s e of the A5L PG A in these programsresu lted in additional changes and improvements, which were incor pora ted into theA6L PGA model.The A6L P G A model .-The A6L PGA was originally intended to be the cr ew tra in-

ing and flight configuration model. Changes and improvements r esul ting from testingand cr ew evaluation of the A5L PG A that were incorpora ted i n the A6L PG A includedaddition of a mobility joint at the ankles to provide for ea si er donning and doffing of theboots, lengthening of the pr es su re sealing closure in the front lower tor so to incr eas eease of donning and closing of the closu re, replacement of the neckring with a morerel iable and positive locking type that had r etra ctab le la tche s instead of the single-piston-ring type used in the A5L design, and redesign of el ect ric al connectors and wr istdisconnects to provide eas ier-to-oper ate and more positive locking feat ures .Most of these changes were made to improve crew operation of t he PGA; however,one significant change w a s made as a resu lt of a cable fail ure that occu rre d duringlow- pres sure chamber testing of the EMU. The cable break in the crotch ar e a occu rred

during a step-up/step-down exe rci se to simulate high metabolic loads. The fric tionand loading imposed on the cable, which passed through Teflon guides while r es tra ini ngthe axia l fo rc e induced by thigh convolute motion, caused the cable to break. Thes eTeflon guides cra cked and caused exce ssive wear on the cable , which eventually broke.The crotch/thigh rest rain t syst em was redesigned to incorporate a pulley on the insi deof each leg in lieu of the Teflon guides, a change that enabled a more erec t standingposture and increased ease in moving this joint area.Another problem are a uncovered during test ing and us e of the A6L P G A wasballooning of the boot sol e when the PGA was pressu ri ze d, caus ing standing instabili tyof the crewman and an inte rference with the spacecraf t couch foot re st ra in t. Thi sprobl em wa s solved by reinforcing the boot sole with a lightweight internal aluminumhoneycomb truss core.N ew mission require ments also resulted in changes to the A6L P G A configuration.Th es e changes included removing the relie f valve fro m the upper leg and redesigning i tso that it could be pluggeci into a gas connector. This relief valve was requir ed only forPLSS operation to prevent PGA overpressu rization that would resu lt i f the PLSS high-pr ess ur e oxygen regulator failed. Because both the CM and LM spa cecraft ECS's hadover pres sure protective devices, a P G A relief valve w a s not d esi red when the P G A w a sconnected to them. Also, a differential-type p re ssu re gage replac ed the previouslyuse d ambient-r eference-type gage to per mi t both sea-leve l and low-ambient-pressurereadouts. A requirement to permit the crewman to self-administer a medical injection

while wearing the PG A was met by the additon of a self-sealing patch on the right thigh.During the time when qualification testing of the A6L P G A incorporating theabove changes was underway, the Apollo spacecraft 204 accident at the NASAJohn F. Kennedy Space Cente r occurred. A s a result of this accident, a majorrede sign of the PG A incorporated nonflammable materials and protective featureswherever possible.

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Thermal micrometeorite protective cover layer: The need for a n outer PGAcover layer was established ear ly in the development progra m. Puncture and abra sionprotection for the basic TLSA pre ss ure and re stra int laye rs and thermal and micro-meteori te protection during EVA'S on the lunar sur face or i n free space were required.The initial A6L cover l ayer design consisted of a sepa rate jacket and a pair of tro us er smade from multilayer the rma l insulating ma ter ial s like those of the Gemini G-4C spa cesuit. The materia ls cr os s section consisted of alte rnate laye rs of perforated aluminizedMylar film, marquisette, and nonwoven Dacron sandwiched between a high-temperature-resistant outer layer of Nomex fabr ic and an inn er l ayer of neoprene-coated ripstop nylon fabr ic. The sepa rate jacket and tr ou se rs we re to be donned anddoffed over the basic P G A during flight.

To provide complete flammability protection at al l tim es i n the mission when theP G A was worn, the sepa rate jacket and tr ou se rs design was changed to an integratedcove r layer design approach, which led to the ITMG. After extensive materials evalua-tions and testing, the mat eria ls c ro s s section was changed to us e a nonflammable outerlayer of Teflon-coated Beta cloth. The multilayer therm al insulating ma te ri al s we rechanged to seven lay er s of gridded Kapton film se para ted by s ix la ye rs of Beta mar -quisette and an inner layer of neoprene-coated rip stop nylon. Fla ps we re added tocover all exposed areas of the P G A such as the press ure sealing closure and thehardware-to-softgoods interfac es. Nonflammable Ve lcro fast ener ma teri al was use dto keep these flap s closed. A patch of Chromel-R woven stainless steel cloth was addedon the back of the cover la yer to provide higher abr asio n resi sta nce at the PLSS con-tact surface. This design w a s found satisfa ctory and was se lect ed for u se on theApollo 7 mission. The EV gloves and lunar boot ma te ri al s we re als o changed toincorporate nonflammable m ater ials selecte d fo r the ITMG.Electrical harnesse s : The A6L PGA ele ctri cal har ne sse s initially used the sa meconstruction techniques that wer e used fo r the Gemini space suit. Individual wi re swe re molded in a flat belt of silicone rubber . The wiri ng between the ele ctr ica l con-

ne ct or s was covered with nylon cloth.An exhaustive study and development pr og ra m wa s initiated to de ter mine andsubsequently el iminate any possible ignition sourc es in the PGA. The harn es s wasrequired to operate in a high-oxygen environment and in proximity to the cotton CWGma te ri al without posing any hazard of self-ignition o r of igniting the cotton mat er ialunder any combination of f ai lu re conditions, both in the PGA and in the Apollo s pace-cra ft. Fail ures of this type included a shor t circuit of the current-limiting res is to rsin the spacecraft wir ing in conjunction with a fault of the two power w ir es i n the P G Aelectrical harness.A method wa s developed fo r construc ting the ent ire h ar ne ss by braiding twisted

shielded pairs. This procedure produced a ha rn es s with excellent flexibility in twoaxes, as opposed to the one-axis flexibility of the si lic one belt, and with a tensilestrength grea ter than the sum of the tensile str engt hs of the individual wire conductors.To further increa se the durability, the primar y conductors wer e constructed ofCopperply, a cdpper-plated steel mat eria l with approximately 30 percent of the con-ductivity of copper. The superior strength of th is mate rial permit ted the us e of asmall er wire si ze , which incre ase d the flexibility and retaine d the require d tensilestrength. At the sa me time, the higher ele ctri cal res ist an ce of this wi re, because ofthe small size and higher res istivity, caused fusion at far lower curr ent s during24


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electrical overload, permitting the use of a minimum-weight cover material.Teflon-coated Beta cloth was initially used as the protective cove r but was subsequentlyreplace d by T- 162 Teflon cloth when the Teflon-coated Beta cloth proved suscep tibleto wear and frequent patching o r replacement.Other c hanges made to the P G A included replacement of the polyurethane boot so le

material with a le s s flammable silicone mate rial and finally with a nonflammable moldedFluorel rubb er, replacement of polycarbonate plastic actuation tabs on connectors anddisc onnects with aluminum tab s, addition of redundant locking fe atures to all pressureintegrity connectors and to the pre ss ur e sealing clos ure, covering of the polyurethanefoam vent pad in the helmet with metal foil and a hydroformed aluminum cover, andaddition of a Fluorel rubber coating to the I V pressure glove bladder.While the redesign to incorporate nonflammable materials was being accom-plished, the crewmen selecte d to fly the fir st orbital mission, Apollo 7, wer e providedwith modified A6L tra ining PGA's. During training in the C M simulat or, the Apollo 7crewme n experienced difficulty in operating controls requir ed to safely re ent er theEarth atmosphere in a contingency mode with the spacecraft decompressed. This

problem w as caused by the excessive upper a rm and shoulder widths of the P G A ' sresulting in i nterfere nce when all thr ee crewmen we re lying side by side in the couches.To alleviate this problem, the a r m s of the P G A ' s wer e changed to replace the ar mrotational bearings with a newly designed elbow convolute having a nylon net restraint.Ar m mobility was reduced as a re su lt of th is change, but because the initia l Apollomissions did not require EVA or a high degree of pr essu riz ed PG A mobility, armmobility was found acceptable.During this period, prob lems with materia ls and molding techniques were encoun-te red in the manufacture of the bubble-shaped helmet. Special molding techniquesusing tempe ratu re and pr es su re w ere developed to ensu re an even thickness throughoutthe she ll of t he helmet and to provide good optical charac ter ist ics . Only the highestgrade polycarbonate raw mat eria ls available were used; however, a high rejectionra t e resul ted because of dir t inclusion. Also, the attachment of the polycarbonate shel lto the helmet-half neckring by adhesive bonding was made stronger and more impactre si ta nt by the addition of machined, bayonet-type mating grooves that provided amechanical inte rfac e. To allow drinking water and food probes to be inse rted into thehelmet without losing pres suri zat ion, an aluminum feedpor t was added on the left side.A purge valve that al so plugged into this feedport was evaluated but w a s found to be toodifficult to operat e because of visibility and ar m re ach limitat ions. For this reason,and to alleviate the need for a complex interface with the EVVA, the purge valve wasredesigned to plug into an outlet ga s connector, which w a s satisfactory.Long sle eves we re incorporated in the L C G to increase metabolic heat removalcapacity and to provide lower arm cooling. A zipper was added in the crotch a re a toprovide an opening for body waste management. Also, noncollapsible si licone rubberr i s e r tubes we re provided between the LCG manifold and the LCG multiple waterconnector, and aluminum fittings were incorporated at the LCG manifold and risertube junctions. Thes e changes were effected to prevent collapsing of t he r i s e r tubes,which would res ul t in blockage and lo ss of cooling. Because of the ex tensive na ture ofthese redesigns, the resultant P G A model was designated the A7L P G A .

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The A7L PG A model . The A7L PGA represented the final design model for theApollo 7 to 14 missions. Changes and improvemen ts resulting from qualificationtesting and crew evaluation during the initial orbi tal flig hts were incorp orated into theApollo 11configuration previously desc ribed in thi s rep ort . Significant improvementso r changes to the A7L PGA made between the Apollo 7 and 1 4 missions a r e describedin the following sections.The I V P G A for the CMP: To save weight and reduce the bulk iness of the P G Aworn by the CMP, who was not required to perform EVA, an I V version of theA7L EV PGA w a s developed. This I V P G A consisted basically of an EV P G A withfea tur es removed that were not requ ired . The ITMG w a s replaced by a lighter weightcover layer; one set of gas connectors, the LCG wate r connector, and the PLSS in te r-facing attachment f eatur es were omitted fr om the I V design. Because the Apollo 8 mis-sion did not require EVA capability, all thr ee crewme n were provided an I V P G A .The CMP for the Apollo 9 to 1 4 missions w a s provided with the I V P G A .The EVVA: The EVVA used on the Apollo 9 mission was designed to attenuatelight and heat energy, to protect the pr es su re helmet from accidental impact, and toprovide a nearly unobstructed and undistorted field of vision. Light seal s, located alongthe lower r i m of the protective vis or and the upper r im of the Sun vi so r, we re used topreven t any leakage of l ight o r ultraviolet r ay s between the two visor assemblie s andthe shell assembly. A collar constructed from ITMG mater ials w as attached aroundthe base of the EVVA to provide thermal and micrometeoroid protection for the EVVA/PG A inte rface ar ea . Thermal insulation fo r the helmet was contained under the EVVAshell. The viso r assembli es, the pivot mechanisms, the collar assembly, and thelatching mechanism were attached to a polycarbonate shell assembly.The protective visor , a transparent, ultraviolet-stabilized polycarbonate shield,provided impact protection to the P G A helmet and thermal insulation during dark/coldenvironmental operations. The Sun visor provided ultraviolet absorption and was

coated to provide light attenuation and to minimize heat leak into the helmet. Bothvi sors were made of polycarbonate plasti c and were molded by techniques used fo r thepr es su re helmet shell. Each visor could be positioned up or down as required by thecrewman. The pivot mechanisms, located on each side of the EVVA she ll, were supportand pivot devices for the protective visor and the Sun vis or. An attachment and lockmechanism allowed the lower r i m of the EVVA to be tightened around the bottom of thepr es su re helmet for positive retention.The LEVA: The LEVA used fo r the Apollo 11 to 17 missions in corporatedimprovements required as a result of thermal qualification testi ng and of an in crease i nthe anticipated lunar su rfa ce tem peratu re environment. These changes included thefollowing improvements.1. Increased protection fro m ultraviol et radiation and gre ate r t hermal stabilitywas accomplished by replacing the polycarbonate Sun vis or with a polysulphone Sunvisor that had a higher tempe ratu re limit and grea ter ultraviolet absorption.2. Increased protection w a s provided for thermal-optical coatings on the viso rs.The EVVA Sun-visor coating, required to reduce the environmental temperatures ofthe plastic to acceptable values, was vacuum deposited on the vis or outer sur fac e and

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basically unprotected. Accidental coating removal during handling and use, regard-less of the c a re taken, resulted in the need to coat the inner su rf ac e of t he LEVA Sunviso r instead of the outer surfac e.3 . Incr eased protection for the v is or s was provided by enlarging the she ll toallow the visor s to ri de inside ra the r than outside as on the EVVA.4. The addition of sunshades (on each side) improved visibility fo r normaloperations on the lunar surface . Thes e sunshades were constructed of fibe rgl assand coated on the outer sur faces with white paint and on the inner sur faces withblack enamel. The sunshades were attached to the visor pivot mechanism and could belowered independently of the Sun vis or and of each other to prevent light penetration ofthe side-viewing areas, thereby reducing low-angle solar glare.The LEVA worn on the Apollo 11 mission was improved for the Apollo 12 missionand incor pora ted the following changes.1. Improved clearances throughout the assembly (visor/visor , visor/shell,visor helmet)2 . Improved Sun-visor opti cs using a high-grade polysulphone ma te ria l3 . Improved re mote control unit (RCU) visibility by optimizing the tab locations,tab shelf distances, light seals, and thermal collar to enhance this critical interface4. Improved pivot mechanisms that allowed more precise torque adjustment forviso r actuating forc e5 , Improved sunshade design for ea se of operation of the bli nders with the Sun

viso r in the rais ed position, which w a s needed f o r looking into shadows at right angl esto the SunThe LEVA w a s modified for the Apollo 1 4 to 17 missions to incorporat e a ce ntereyeshade , recommended by the Apollo 12 crew. Thi s cen ter eyeshade consisted of anintegral hinged-door mechanism positioned by the action of a ratche t device. Theeyeshade reduced g la re when walking toward the Sun during low-Sun-angle conditions.Thi s configuration was satisfactorily used on all subsequent Apollo missions.Ar m mobility: After the ar m bearings were omitted fro m the A7L P G A ' s beforethe Apollo 7 mission, development w a s implemented to provide the incr eas ed a r m andshoulder mobility that was neces sary for lunar surface work tasks. This developmentresulted in the design of a low-profile a r m bearing that minimized C M couch interfaceproblems . This design w a s evaluated by the Apollo 11 EVA crewmen and found to be aconsiderable improvement over the existent flight configuration. The low-profile a r mbearings were incorporated into the A7L EV P G A and successfully used on the Apollo 11and subsequent missions.Materials durability : The gridded Kapton film used in the multilayer th ermalinsulation of the ITMG had very low te ar strength. Also, during manufacturing, theBeta marquise tte spac er mate rial caused numerous problems in handling: cutting;shaping, and edgelocking. To solve these problems, the mat eria ls c ro ss section was

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modified for the A7L EV PGA's used on the Apollo 10 to 14 mis sions to incorpo ra te twolaye rs of Kapton fil m laminated to Beta marquiset te and five laye rs of perforated Mylarfilm intersper sed with four Dacron space r lay ers. The laminated Kapton and Betamarquiset te eliminated the handling problems, and the Mylar fil m, a stronger materialthan the Kapton, incr eased durability. The two la ye rs of the Kapton fil m we re retainedfo r flam e impingement protection. To improve abrasion resi stan ce, external scuffpatches of Teflon fab ric we re attached to the knee, wais t, elbow, and shoulder areas.Mobility relief was designed into the knee, elbow, shoulder , and wai st areas to reducerestrictions.

The redesigned ITMG sati sfac tori ly accomplished the design objectives and wassuccessfully used during the Apollo 11, 12, and 14 lunar surface EVA's.Dual-flow purge valve: Before the Apollo 14 miss ion, the purge valve, use d inconjunction with the OPS to provide fo r an open-loop-type EMU pressuri za ti on andventilation, was redesigned to provide two positions for flow. A lower flow mode witha 1.8-kg/hr (4 lb/hr) rate was added to in crea se the operating time of the OPS whenused in conjunction with the BSLSS, desc ribed lat er in this rep ort .The A7LB PGA model. - Additional r equ ireme nts fo r the Apollo 15 to 17 mis sio nsresul ted in red esign of both the A7L EV P G A and IV P G A configurations. Theseadditional requ irements included an inc re ase in the number of lunar sur fac e EVAperi ods to thr ee and an increas e in the time of each EVA to 8 hour s. The LRV becameavailable f o r the se mis sions, which added the requi reme nt fo r waist mobility to enablecrewmen to get on, dri ve, and get off the vehicle. Also, the CMP was req uire d toperform a n EVA during the retur n to Earth to ret rie ve fil m packages from a cameralocated in the se rv ice module of the Apollo spacecra ft. Significant changes incorporat edinto the A'ILB PGA's and the problems encountered a r e desc ribe d in the followingparagraphs.The A7LB PGA fo r the CMP: The configuration of the A7LB CMP P G A , selectedto provide a 1-hour EVA capability, was essentially the same as the A7L EV P G A withimprovements resulting fro m previous mission exper iences; it was designed to main-tain as much commonality as possible with the A7LB EV PGA's used by the CDR and theLMP. Major changes included incorporation of mo re durable and abr asi on- res ist antTLSA ar ms and leg s, which were standard ized fo r both PGA configurations; rede signof the pr es su re relie f valve with a flow capabi lity of 5. 53 ki lograms ( 1 2 . 2 pounds)of oxygen per hour, which wa s the maximum flow of the CM ECS life- suppor t umbil ica l;replacement of the Teflon-coated Beta cloth outer l ayer of the ITMG with a moreabrasion-resistant woven Teflon fabric; and the addition of a PCV that plugged into agas connector to maintain pressure in conjunction with the CM ECS umbilical.The CMP was provided. EV gloves and used one OP the oth er cre wmen 's LEVA'Sthat had been brought back fr om the lunar su rface . The Apollo 15 to 17 CMP's suc cess-fully completed EVA's and retu rne d the fil m packages with no maj or pro blems.The A7LB P G A fo r the CDR and the LMP: The A7LB EV P G A worn by the CDRand the LMP for lun ar su rfac e exploration incorporated r edes igns to permit waistmobility not available in the A7L EV P G A . The A7LB EV PGA a lso had a reinforcedand more durable pressure bladder.

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The waist convolute joint provided increased waist mobility in forw ard , backward,and side -to- side directions. Incorporation of the waist convolute into the A7LB PG Aprecluded the use of the A7L-type r e a r vertical entry clo sure , and hardware locationand donning problems precluded the use of a horizontal closure . Therefor e, a new entryclos ure was provided that extended fr om the upper right front side n ear the torso/neckinte rfac e to under the right ar m , passed diagonally acr os s the back, and ended at thelower left front side. G a s sealing was accomplished by a Talon omnienvironmental-bar r i e r (OEB) ype pres sure - seal c losure located inside a load-carrying restraintzipper.

The A7LB EV PGA al so incorporated a neck convolute to provide both forwardand backward neck mobility. . This fe atur e not only allowed varia tions in head positionbut als o improved crewman visibility for LRV driving. A neck convolute restraintcable sys tem provided convolute adjustment capability to accommodate varia tions increwman head and neck height. To incr ea se the durability and ab ras ion resis tance ofthe pressure bladder, a nylon-cloth scuff layer w a s bonded to the enti re inner surf aceof the nylon-coated neoprene bladder, the joint convolutes, and the boot bladder.Other changes incorporated in the A7LB EV P G A ' s we re the addition of hingedpulleys at the ends of the shoulder joint cable guides, which reduced torque; an incr easein the diameter of the glove wr is t disconnect s to provide for ea si er donning and grea te rwr is t comfort ; an improved glove bladder assembly to provide incr eased thumb dex-terity, comfort, and hand-clenching capability; and a redesigned press ure relief valveincorpocating a manual ove rri de cap with an increased flow capability of 5.53 kg/hr(1 2 . 2 lb/hr) .

Com m un ca t i o ns C a r r i e r Asse mb IThe personal communications equip- r Earphonement for the suit ed mode of operations wasdesigned into the helmet for Mercury, Gem-ini, and ea rl y prototype Apollo space suits.With the advent of the AX5L bubble helmet, -it became necessary to remove the commu-nications equipment (microphones, ear-phones, and related elect ric al harness)fr om the helmet and to affix the equipment

directly on the crewman's head. This de-vice, originally intended to provide forcommunications when the helmet was notworn, w a s known as the communicationscarrier (fig. 31) . drivers molded in

on common tab

Figure 31. - Communications carrier.29


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The initial design of the communications ca r r i e r incorp orated microphones andearphones contained in plastic earcups . The earcup s were covered with nylon fabr icand suspended fro m a str ap arra ngement that held them on the head.Through te sts and training exercise s, i t became apparent that the following basicproblems required correction.1. The s tr ap arrangement did not hold the communications c ar ri er adequately i nposition on the head.2. The suppressor circuit produced unacceptable intelligibility.3. The 30-decibel isolation provided by the polycarbonate earcups w a s notsufficient. Testing showed that a leve l of approximately 50 to 60 decibels was necessary.4 . The br itt le plas tic (diallyl phthalate) of the e lec tri cal connector was easilydamaged.Because of these problems, a complete redesig n w a s implemented. The effortincluded the following major changes :1. The strap-suspe nsion syst em was changed to a skullcap, and the ear sealswere changed fr om plastic to deerskin-l eather-co vered foam ins ert s.2 . , The noise-suppressor configuration was eliminated.3. The microphone and earphone modules wer e molded into silicone rubb erearcups.4 . The el ect ri cal connector was changed to an identical type made ofpolycarbonate.The only other change made was in the procu rement of new microphones andearphones. The microphone power leads were shielded. Communications ca r ri er swith this shielding were required for PLSS operation because of the proximity to thePLSS antkixia. Fur the r attempts to improve the radiofrequency inte rfer ence suscep-tibility by double shielding the microphone wires wer e unsuccessfu l. The configurationresulting from this redesign proved acceptable for al l the Apollo miss ions .

B i o ins t r u m e n t a t i on S y stemThe development of bioinstrumentation and relate d hardware w a s primarilyprogram or mission or iented and was dir ected toward fulfilling one o r more of thefollowing objectives: operational in-flight safe ty monitoring, in-flight medical experi -ments, or safety monitoring during ground-based operations.

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The bioinstrumentation system (fig. 32) consists of one electrocardiograph (ECG)signa l conditioner, one impedance pneumograph ( Z P N ) signal conditioner, one direc tcur ren t (dc)/dc convert er, one ster nal electrode harness, and one axillary electrodeharness.The ECG signal conditioner with assoc iated electrodes is designed to provide in-flight measurement s of cre wmembers' ECG activity and to develop a signal waveranging between 0 and 5 vol ts peak-to-peak, which is representative of crewman ECGactivity. The unit is provided with a device that permits preflight gain adjustments.The Z P N signal conditioner and associated electrodes are designed for measure-ment of a change in the trans thoracic impedance to a low-level current at a frequencyof approximately 50 kilohertz. Measurement is obtained fr om a pair of appropriatelyplaced e lectrodes that pres ent a changing impedance to a signal conditioner, which inturn develops si gnals (0 to 5 volts peak to peak) corresponding to the respiration rat eover a wide dynamic range of resp ira tory activity of the crewman o r test subject. This

Teflon-coated Beta cloth- -Teflon-jacketed wires in braided beltElectrodes(applied to crewman's chest) Cmm unica tionscarrier connector

ECG signal conditionerdc-to-dc

- PN signal conditioner-1Figure 32. - Bioinstrumentation system.

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unit is provided with cont rol s that per mi t preflight adju stme nts of cir cu it gain to accom-modate the cha ra ct er is ti cs of the individual.The dc/dc power converter is a component of the bioins trumentation sys te m thatde liv ers the regulated positive 10-volt and negative 10-volt power to each signal con-ditioner. The convert er is powered f ro m the unipolar nominal 16.8 volts available for

suit

apollo experience report development of the extravehicular mobility unit

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