There are other syndromes as well. Lack of gravity causes blood to pool in the head and upper chest, producing the pumpkin-faced look familiar from Shuttle videos. Eventually, the body reacts to this congestion by reducing the volume of blood. The long-term effects of this are poorly understood. About this time, red blood cell production falls off in the bone marrow. Those red blood cells which are produced in free-fall tend to be interestingly malformed.

And then, of course, there's the radiation hazard. No one in space has been severely nuked yet, but if a solar flare caught a crew in deep space, the results could be lethal.

These are not insurmountable medical challenges, but they *are* real problems in real-life space experience. Actually, it's rather surprising that an organism that evolved for billions of years in gravity can survive *at all* in free-fall. It's a tribute to human strength and plasticity that we can survive and thrive for quite a while without any gravity. However, we now know what it would be like to settle in space for long periods. It's neither easy nor pleasant.

And yet, NASA is still committed to putting people in space. They're not quite sure why people should go there, nor what people will do in space once they're there, but they are bound and determined to do this despite all obstacles.

If there were big money to be made from settling people in space, that would be a different prospect. A commercial career in free-fall would probably be safer, happier, and more rewarding than, say, bomb-disposal, or test-pilot work, or maybe even coal-mining. But the only real moneymaker in space commerce (to date, at least) is the communications satellite industry. The comsat industry wants nothing to do with people in orbit.

Consider this: it costs $200 million to make one shuttle flight. For $200 million you can start your own communications satellite