Suited for Spacewalking pdf - Virtual Astronaut

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