• Question: How long does it take for your body to acclimatize to being in the craft? Is it similar at all to mountaineering?

    Asked by Anon to Delma, Floris, Jean-François, Katie, Kevin, Jon, Adrian on 6 Jan 2016. This question was also asked by jxnnas, mrmull.
    • Photo: Kevin Fong

      Kevin Fong answered on 6 Jan 2016:

      The worst part is the first few days. Most rookie astronauts feel sick or are sick for the first 48 to 72 hours in space. After that I’m told you get used to the new environment pretty quickly.

      The changes that happen to your body in space are mostly adaptive. That is to say that they make sense for your body when you are in a weightless environment. It’s when you come home to Earth that you run into problems.

      Astronauts can also have trouble sleeping, because some of the most important normal cues for day and night cycles are lost in space (there are 17 sunrises each day when you’re orbiting the Earth and you don’t have the same variation in temperature).