Going to space, and living there for an extended period of time, has long been a subject of both wonder and debate among citizens of Earth. Some feel that life in space is the answer to our problems here on this planet, and that eventually, many people will be living in space or on other planets, or at least spending a lot of time exploring the local solar system. Others believe that being in space for long periods of time is not a natural way for humans to live, or that it is senseless to spend money on space travel when we have so many internal problems. Regardless of which category you fall into, here are some irrefutable facts about space that we’ve discovered from the in-orbit missions we’ve done so far.
Astronauts get taller.
Weirdly enough, astronauts living on the International Space Station (ISS) can get taller. This is because anti-gravity conditions allow the spine to expand. Once they are back on earth, people go back to their regular heights. This brings up some interesting ideas about how using anti-gravity chambers here on earth could be helpful for those who have back problems.
Body fluids get distributed oddly.
Being in zero G means your bodily fluids settle differently inside of you. For this reason, it often appears that astronauts have puffy faces when first in orbit, while the rest of them, especially their legs, appears thinner. Once they have adjusted to no gravity, they go back to looking normal.
Astronauts forget about gravity.
It may seem silly, but it is hard for some to readjust to life on earth after living with no gravity. Astronauts have reported having trouble walking, or dropping things because they forget that they can’t just allow them to float.
Muscle mass gets lost.
You may not realize it, but day-to-day life on Earth requires exercise, even if you are just eating, sleeping, and sitting at a desk working. Living in gravity requires us to use our muscles all of the time. Astronauts have to exercise for at least two hours a day in space just to maintain the amount of muscle mass they will need back on earth.
Bone density is lost.
Much like the problem with muscle mass, bone density also gets lost because astronauts are not using their muscles the way they would back on earth. Rigorous exercise is needed to maintain proper bone density in space.
Astronauts have trouble sleeping.
Weirdest of all, when astronauts try to rest, they often have a hard time because they see flashes of light constantly when they try to relax and close their eyes. This is because they are seeing cosmic rays, without having the proper protection of the atmosphere. Of course, it can also be difficult to sleep in such an alien environment, literally, and in a situation where there is neither day nor night.
Does this mean that humans should not go to space? We simply don’t know enough about a lot of the effects of long-term space travel to really tell, and we so far only have data on short distance or in-orbit travel with no gravity. Scenarios like Star Trek, for example, involve much longer times in space, but to make the stories more interesting, these fictional worlds can also travel at the speed of light, with gravity. One thing is clear so far – space travel as we know it now takes a toll on the body, and can only be undertaken if astronauts are willing to exercise and run some of the risks that living in zero G entails.
Source: Source: http://www.space.com/20730-human-body-spaceflight-weird-facts.html, http://interactive.aljazeera.com/aje/2016/space-astronauts-iss-return-peake-malenchenko-kopra/
