Astronauts face a large number of other health risks during their stay in space. In a weightless environment, muscles aren't used as much, which can lead to them weakening and atrophying. Additionally ...
However, by 2017, when SpaceX re-flew a Falcon 9 rocket for the first time, the writing was on the wall. "This is a very important step, we sincerely congratulate our colleague on this achievement," ...