How space travel reshapes the body: From muscles to mental health

In the absence of gravity, muscle mass disappears because the resistance training stops. When the astronaut returns to normal gravity, the heart may have weakened and may not function properly

The return of Sunita Williams and Barry “Butch” Wilmore from the International Space Station has sparked public interest in the health implications of spending long periods in space. The duo were up for 286 days instead of the eight originally scheduled.

 

Keeping people healthy in space is a complex task. Fifty years of research into this has resulted in major advances in our understanding of the body, and the development of many useful tools.

 

Running space stations, (or taking trips to Mars as Nasa plans) involve very long stints in space. It should be noted that Williams and Wilmore were