Suited for Spacewalking pdf - Virtual Astronaut

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Project MercuryEarly spacesuit design.Designers learned in their search for the perfect suitthat it was not necessary to provide full sea-levelpressure. A suit pressure of 24.13 kilopascals (sealevel–101 kilopascals) would suffice quite nicely ifthe wearer breathed pure oxygen. Supplying pureoxygen at this low pressure actually provides thebreather with more oxygen than an unsuited personbreathes at sea level.(Only one-fifth of the air at sealevel is oxygen.)Va rious techniques were used for con s t ru c t i n gp re s s u re garm e n t s .Some appro a ches employed a ri g i dl ayer with special joints of rings or cables or som eother device to permit limb move m e n t s .Others usedn on - s t re t ch fabrics—laced-up corset fashion .With the advent of pressurized aircraft cabins,comfort and mobility in the suit when it wasu n p re s s u ri zed became prime objectives in suitdesign.The suit could then be inflated in the eventthat the aircraft cabin lost pressure.By the time NASA began the Merc u rymanned space flight program,the best full-pressuresuit design consisted of an inner gas-bladder layerof neoprene-coated fabric and an outer restraintlayer of aluminized nylon. The first layer retainedpure oxygen at 34.5 kilopascals; the second layerprevented the first from expanding like a balloon.This second fabric restraint layer directed the oxygenpressure inward on the astronaut. The limbs ofthe suit did not bend in a hinge fashion as dohuman arms and legs. Instead, the fabric arms andlegs bent in a gentle curve, which restricted movement.When the astronaut moved one of his arms,the bending creased or folded the fabric inward nearthe joints, decreasing the volume of the suit andincreasing its total pressure slightly. Fortunately forthe comfort of the Mercury astronauts,the Mercurysuit was designed to serve only as a pressure backupif the spacecraft cabin decompressed. No Mercurycapsule ever lost pressure during a mission, and thesuits remained uninflated.Project Mercury astronauts.(Front row, left to right) Walter M.Schirra,Jr.,Donald K.Slayton,John H.Glenn,Jr.,M.Scott Carpenter. (Back row, leftto right) Alan B.Shepard, Jr., Virgil I. Grissom,L.Gordon Cooper, Jr.1 2 • Suited for Spacewalking An Activity Guide for Technology Education, Mathematics, and Science, EG- 1 9 9 8 - 0 3 - 1 1 2 - H Q
Project GeminiThe six flights of the Merc u ry series weref o ll owed by ten flights in the Gemini pro g ra m .Suit designers were faced with new pro b l e m s . No ton ly would a Gemini suit have to serve as a pre s-s u re backup to the spacecra ft ca b i n , but also as ane s cape suit if ejection seats had to be fired for ana b o rted launch and as an EMU for extra ve h i c u l a ra c t i v i ty. To increase mobility and com f o rt of thesuit for lon g - t e rm wear, designers departed fromthe Merc u ry suit con c e p t . Instead of fabric joints,t h ey chose a con s t ru c t i on that employed a bladderre s t rained by a net. The bladder was an anthro p o-m o rph i ca lly shaped layer of neopre n e - c o a t e dnyl on . That was cove red in turn with a layer ofTe f l on®-coated nyl on netting. The netting, s l i g h t-ly smaller than the pre s s u re bladder, limited inflati on of the bladder and retained the pre s s u re loadin mu ch the same way automobile tires retained theload in inner tubes in the days before tubeless tire s .The new spacesuit fe a t u red improved mobility inthe shoulders and arms and was more com f o rt a b l ewhen worn unpre s s u ri zed during space flights lastingas long as 14 days .The first Gemini astronaut to leave his vehicle(“go EVA”) was Edward White, II. White exitedfrom the Gemini 4 space capsule on June 3,1965—just a few months after Leonov made the firstSoviet spacewalk. For a half-hour, White tumbledand rolled in space, connected to the capsule only byan oxygen-feed hose that served secondary functionsas a tether line and a communication link withthe capsule. Although the term “spacewalk” wascoined for the Gemini program, no actual walkingwas involved.On his spacewalk, White used a smallhand-held pro p u l s i on gun for maneuve ring inspace. When he pulled a trigger, the gun releasedjets of nitrogen that propelled him in the oppositedirection.It was the first personal maneuvering unitused in space.Upon completion of the Gemini program,NASA astronauts had logged nearly 12 additionalEdward H. White’s historic spacewalk.hours of EVA experience. Approximately one-halfof that time was spent merely standing up throughthe open hatch.One of the most important lessons learnedduring the Gemini program was that EVAs werenot as simple as they looked. Moving around inspace required a great deal of work.The work couldbe lessened, h ow eve r, by extensive training onE a rt h . The most effe c t i ve training took placeunderwater. Wearing specially-weighted spacesuitswhile in a deep tank of water gave later Geminicrew members adequate practice in maneuvers theywould soon perform in space. It was also learnedthat a better method of cooling the astronaut wasrequired.The gas cooling system could not removeheat and moisture as rapidly as the astronaut producedthem, and the inside of the helmet visorquickly fogged over making it difficult to see.Project ApolloFollowing Gemini, the Apollo program addeda new dimension in spacesuit design because actualspacewalks (on the surface of the Moon) were nowSuited for Spacewalking An Activity Guide for Technology Education, Mathematics, and Science, EG-1998-03-112-HQ • 1 3
Page 1: National Aeronauticsand Space Admin
Page 6 and 7: National Education StandardsThe act
Page 8 and 9: National Mathematics StandardsNatio
Page 10 and 11: M e a s u r e m e n tThis activity
Page 12 and 13: need to be able to move arms, hands
Page 14 and 15: out in the vacuum of space.Dissolve
Page 18 and 19: to occur for the first time. As wit
Page 20 and 21: crew, an additional portable heat s
Page 22 and 23: and reentry, special orange-colored
Page 24 and 25: The SCU contains lines for power, c
Page 26 and 27: 17.Communications Carrier Assembly
Page 28 and 29: settings to be read. Setting number
Page 30 and 31: digital display on the chest-mounte
Page 32 and 33: Astronaut Joe Tanner works on the H
Page 34 and 35: humidity when oxygen is flowing fro
Page 36 and 37: The problem of picking up rocks and
Page 38 and 39: Bruce McCandless II pilots the MMU
Page 40 and 41: Mark C.Lee test flies the Simplifie
Page 42 and 43: STS-76 astronaut Michael R. Cliffor
Page 44 and 45: Spacesuit technicians test the mobi
Page 46 and 47: Future spacewalkers will roam the s
Page 48 and 49: Introduction:The steps spacesuit en
Page 50 and 51: Design BriefC o n t ex t :Spacesuit
Page 52 and 53: Interface Control DocumentPage 1 Of
Page 54 and 55: Pulley close-upviewthe buck e t . T
Page 56 and 57: to them. Use a metric ruler for mea
Page 58 and 59: steel would make an excellent micro
Page 60 and 61: d ay or tw o, Ap o llo spacesuit ma
Page 63 and 64: Sleeve and Leg TesterInflated segme
Page 65 and 66: ity alone.If a scale were present,
Page 67 and 68:
Exploration BriefMicrometeoroids an
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InvestigationPotato Astronaut—Par
Page 71 and 72:
Exploration BriefKeeping Your CoolC
Page 73 and 74:
AssessmentHave students design a gr
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InvestigationInsulating LayersIn th
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e nv i ronment experienced in Earth
Page 79 and 80:
Arm Range of Movement Data SheetSub
Page 81 and 82:
Body Size Range MeasurementsBased o
Page 83 and 84:
ProcedureStep 1. Obtain the materia
Page 85 and 86:
Magnified view oftire valve and cla
Page 87 and 88:
Extensions• Compare the stiffness
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2. Tethers4. Connector Seal TestPla
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9. Vacuum Experiment - 1Obtain an e
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You can investigate neutral buoyanc
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MMUMercuryORUPLSSRegolithRMSSCUSkyl
Page 97 and 98:
NA S A’s Central Ope ra tion of R
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Suited for Spacew a l k i n gA Te a
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