10-16-2015, 07:41 PM
The standard figure generally accepted for rotation tolerance is 2 RPM (and this is what High Frontier uses). Above that, and some people will start to experience motion sickness, especially when they first arrive.
But Al Globus (a long-time collaborator of mine, though I met him in person for the first time just today) recently did a literature review on human tolerance to spin. He finds that there is actually very little evidence for that 2 RPM figure — that the most careful experiments actually show the threshold is more like 4 RPM.
At 4 RPM, you can build a very small colony; in fact, probably too small to be really a "colony" at all (though it could be quite useful for hotels or other spacecraft).
But, on the other hand, your basic point is right: we won't really know for sure until we try it.
In Al's talk this morning, he pointed out that once we get a large number of space tourists going into orbit, they are not going to want to learn how to use a zero-G toilet. It's a complicated and unpleasant business. So there will be a strong incentive for even early hotels to provide some gravity, even when the point is to play in zero-G most of the time. But exactly how much gravity is needed to make a toilet reasonably easy to use is another unknown!
But Al Globus (a long-time collaborator of mine, though I met him in person for the first time just today) recently did a literature review on human tolerance to spin. He finds that there is actually very little evidence for that 2 RPM figure — that the most careful experiments actually show the threshold is more like 4 RPM.
At 4 RPM, you can build a very small colony; in fact, probably too small to be really a "colony" at all (though it could be quite useful for hotels or other spacecraft).
But, on the other hand, your basic point is right: we won't really know for sure until we try it.
In Al's talk this morning, he pointed out that once we get a large number of space tourists going into orbit, they are not going to want to learn how to use a zero-G toilet. It's a complicated and unpleasant business. So there will be a strong incentive for even early hotels to provide some gravity, even when the point is to play in zero-G most of the time. But exactly how much gravity is needed to make a toilet reasonably easy to use is another unknown!
Joe Strout
Lead Developer, High Frontier