The mysterious syndrome impairing astronauts’ sight

Short form: zero gravity over a span of weeks or months shifts fluids up into astronauts heads, applying pressure to the back of eyeballs, trashing their vision. One astronaut went from 20/20 to 20/100. It’s not yet clear if this is temporary or permanent, but it’s moderately disastrous for long duration spaceflight such as trips to Mars.

There is, of course, a simple solution: artificial gravity. Centrifugal force will do the job. But the question is, what level of gravity is needed? If you go to 3/8 of a G, Mars gravity, will you be just fine forever, or will it just take longer? Can we get by on 1/6 G, Lunar gravity? 1/10 of  G? 1/20? 1/100?

These are questions that *cannot* be answered on the ISS. We need a real space station, one that either has different rotation rates over a span or years, or multiple levels with different G-levels. This would obviously be a better setup then pure zero-g fr a “space hotel.” It’s not even remotely certain that all space tourists will be able to well tolerate or even want zero-g non-stop for the duration of their stay; a rotating station, especially one attached to a zero-g module via a rotary bearing airlock, would provide both environments within just a moments travel.

Best solution: develop some good zero-g, vacuum-capable 3D printers that can work with aluminum and steel and titanium, and send to the ISS along with a modified woodchipper. Feed the ISS into the chipper then the printer a module at a time, turning it into a properly designed station, one with inflatable modules and artificial gravity.