In space, heads swell.
A typical human being is about 60 percent water, and in the free fall of space, the body‚Äôs fluids float upward, into the chest and the head. Legs atrophy, faces puff, and pressure inside the skull rises.
‚ÄúYour head actually feels bloated,‚ÄĚ said Mark E. Kelly, a retired NASA astronaut who flew on four space shuttle missions. ‚ÄúIt kind of feels like you would feel if you hung upside down for a couple of minutes.‚ÄĚ
The human body did not evolve to live in space. And how that alien environment changes the body is not a simple problem, nor is it easily solved. ...