bcw (11/20/82)
From: Bruce C. Wright @ Duke University Re: Space walks under low pressure I'm not sure where I read this (in this group? New Scientist? Science? I'm not sure), but I seem to remember that there have been experiments with putting chimps or other apes into **very** low pressure situations (like maybe < .01 atmospheres), and the results seem to indicate that this is not fatal, if it is short enough. The figures I remember are that consciousness ends in about 10-15 seconds for the chimps, and if they are revived at that point they seem to have no particular long-lasting injury. Presumably for humans it would be a bit longer - maybe 15-20 seconds. That doesn't mean that the consciousness is very useful (it might be rather delirious towards the end for example), but the popular science fiction ideas about "exploding" or whatever are untrue. There are several problems: it is true that with extended exposure to very low pressures bodily fluids will boil, causing dehydration and maybe injury to the microstructure of cells. Also, if exposure is due to explosive de- compression, the victim would probably have quite a coughing fit to remove the air from the lungs down to a lower pressure; this would probably make any type of emergency measures more difficult, especially in a 0-g environment where the coughing would probably propel the victim away from safety or into equipment. I doubt very seriously that there would be any way to have "just a thermal suit with an oxygen mask," because there would be some pretty severe problems with the seal on the mask and with prolonged skin exposure to low pressure. It might be possible to have some type of suit like a diver's wet suit which had a very low pressure but which was more flexible than modern space suits, though; the difficulties with this would be in making something like that which would seal properly and which wouldn't cause the joints to stiffen under the pressure. Bruce C. Wright @ Duke University