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--part1_2d.e1ac286.287a2c58_boundary Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit > At one point, NASA took advantage of a property of space that divers do not > have access to, the lack of pressure. The early suits ran pure oxygen at a > reduced total pressure. The suits used for EVA run 100% O2 at about 4-5 psi. The low psi is required so that the suit stays flexible with little if any effort. Working in space is hard enough without having a suit that cannot bend. This brings on some problems. The first is that the shuttle and station run at 1 atm with 21% O2. So when a person is going to do an EVA they have to breath down on 100% O2 so that they will not get BENT in space when they start working at 4-5 psi or 1/3 atm. And you thought only divers get bent. Fighter pilots can also get bent if they lose cabin pressure at altitude. Think about it, go from 1 atm to say 1/10 atm in less then a second and what goes on with those tiny bubbles? Another problem is when they practice missions in the big water training tank. For the Hubbell scope the tank has to be about 40' deep. So for the practice, which can take up to 8 hours, the astronaut is at depth PLUS that 4-5 psi. Now over 8 hours they can get into a lot of problems if they stayed on 100% or even air. So to keep the high cost training specimens (astronauts) safe they run about 45% NITROX. So even if you get to go above and beyond deco theory and the bends just may follow you. Pete Johnson PS the suits are made in Windsor, CT at Hamilton Sundstrand Div. of UTC. --part1_2d.e1ac286.287a2c58_boundary Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: 7bit <HTML><FONT FACE=arial,helvetica><FONT SIZE=2> <BR><BLOCKQUOTE TYPE=CITE style="BORDER-LEFT: #0000ff 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px; PADDING-LEFT: 5px">At one point, NASA took advantage of a property of space that divers do not <BR>have access to, the lack of pressure. The early suits ran pure oxygen at a <BR>reduced total pressure. </BLOCKQUOTE> <BR> <BR>The suits used for EVA run 100% O2 at about 4-5 psi. The low psi is required <BR>so that the suit stays flexible with little if any effort. Working in space <BR>is hard enough without having a suit that cannot bend. <BR> <BR>This brings on some problems. <BR> <BR>The first is that the shuttle and station run at 1 atm with 21% O2. So when a <BR>person is going to do an EVA they have to breath down on 100% O2 so that they <BR>will not get BENT in space when they start working at 4-5 psi or 1/3 atm. And <BR>you thought only divers get bent. Fighter pilots can also get bent if they <BR>lose cabin pressure at altitude. Think about it, go from 1 atm to say 1/10 <BR>atm in less then a second and what goes on with those tiny bubbles? <BR> <BR>Another problem is when they practice missions in the big water training <BR>tank. For the Hubbell scope the tank has to be about 40' deep. So for the <BR>practice, which can take up to 8 hours, the astronaut is at depth PLUS that <BR>4-5 psi. Now over 8 hours they can get into a lot of problems if they stayed <BR>on 100% or even air. So to keep the high cost training specimens (astronauts) <BR>safe they run about 45% NITROX. <BR> <BR>So even if you get to go above and beyond deco theory and the bends just may <BR>follow you. <BR> <BR>Pete Johnson <BR> <BR> <BR>PS the suits are made in Windsor, CT at Hamilton Sundstrand Div. of UTC.</FONT></HTML> --part1_2d.e1ac286.287a2c58_boundary-- -- Send mail for the `techdiver' mailing list to `techdiver@aquanaut.com'. Send subscribe/unsubscribe requests to `techdiver-request@aquanaut.com'.
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