henry (11/30/82)
The notion that the human body would explode on exposure to vacuum is a myth. This was settled by experiments on both humans and experimental animals long ago. The human body is not a balloon; it is a collection of (mostly) liquids and solids enclosed in a moderately tough skin. If one's body, or a part thereof, is in vacuum for a substantial period (30 seconds? don't remember), the flesh will start to swell. If you get back into pressure, the swelling goes back down. When only short periods of exposure to vacuum are involved, at least, there is no permanent damage. This again is experimental results, not theory. Long exposure to vacuum without some sort of restraint is decidedly unhealthy; the blood-boiling business does become serious if you are patient. But it's not instantaneous by any means. The basic notion of the "space leotard", which Pournelle has written about several times, is that you do not need an airtight shell around your skin. You need air in your helmet, of course, and you need some form of mechanical restraint to prevent body swelling, but the skin itself (which is, after all, a pretty good grade of leather) will provide an adequate gastight seal for the body as a whole. There is evaporation, of course, but this fulfills exactly the role it does on Earth: cooling. The suit then consists of a more-or-less ordinary helmet plus a tight elastic coverall to supply mechanical support to the rest of the skin. Various odd nooks and crannies of the body, difficult to support with elastic materials, are handled by embedding small air-filled bladders between the body and the elastic suit. There may or may not be outer layers of suit to provide thermal insulation and radiation/micrometeorite shielding, but those layers are not airtight. Will this work? Yes. It's been tried; it works. The experiments did not go as far as a complete suit design, and in particular I believe they did not design either gloves or a helmet, but the basic concept was proved in vacuum-chamber tests. What's happening on this now? Basically, nothing. Henry Spencer U of Toronto
pcmcgeer (11/30/82)
There is an easy way to settle this: take a monkey up in Columbia and toss him out, wearing a wet suit, oxygen tank and face-covering helmet. If the monkey is alive after 15 minutes or so, then the pressureless space suits probably work. Of course, the crew of Columbia (or Challenger) will have to put up with a monkey for a few days. Rick.