The effects of space travel on the human body (past and present)

Last week, an American and a Russian — Scott Kelly and Mikhail Kornienko — were selected to spend a year living continuously in space, aboard the International Space Station. Only four other people have done this before. All them were Russian, so Scott Kelly is going to break the American record for time spent in space.

The mission won't start until 2015, and it's part of a much longer term goal — sending people to Mars. We know that spending time in space does take a toll on the human body. For instance, hanging out without gravity means you aren't using your muscles, even the ones that you'd use to support your own weight on Earth. Without use, muscles deteriorate over time. Bone density also drops. Basically, after a few months in space, astronauts return to Earth as weak as little kittens. Which is, to say the least, a less than ideal situation for any future Mars explorers.

Having Kelly and Kornienko stay up for a year will give scientists more data on what happens to the human body in space, give them a chance to test out preventative treatments that could keep astronauts stronger, and allows them to see how the amount of time spent in space affects the amount of time it takes to physically recover from the trip. As an extra research bonus, Kelly is the identical twin brother of Mark Kelly, the astronaut married to former congresswoman Gabrielle Giffords. Which means that there will be a built-in control to compare Kelly to when he comes back from his mission.

In honor of that upcoming experiment, here's an old video that will give you an idea of what we knew (and didn't know) back at the dawn of the space age. Science in Action was a TV show produced by the California Academy of Sciences. In this 1956 episode, they explore the then-still-theoretical physiology of space travel ... with a special guest appearance by Chuck Yeager!

Wikipedia page on the effects of space travel on the human body

Science in Action: Aero Medicine — Part 1 and Part 2 at the Prelinger Archives.


  1. I have an idea for a 2 meter diameter cylindrical space bunk that would provide 1g gravity for 4 sleeping astronauts while spinning at 43-60rpm. I think it would extend the workable lifetime of long term astronauts by 1/3 to 1/2 the amount they could normally work. Who do I have to contact to get someone at NASA to look at my idea?

    1. Sorry but that sounds horrible. Every time you turn over Coriolis effects will mess with your inner ear. If you are going to have artificial gravity then use it for working areas where people need the exercise anyway.

        1. Yeah why doesn’t NASA do that?

          Seriously, there are some options available, but the structural requirements are significant and failure modes become much worse. For example, it is easier to control a fire in microgravity where convection can’t start. One option is to build two vehicles connected by a cable. The difference in the gravitational field along the cable provides real gravity in both parts of the system but if the cable breaks then the bottom component will drop towards Earth and the top component will fly up towards the Van Allen belts. I am unsure which is worse…

  2. Well, if the space travel thing doesn’t work out, hey, we can fill the YouTubes with astronaut vids instead of cat videos, amirite?

  3.  Well, I’ve been traveling forwards for forty years now, and it pretty much sucks. I wanna swap and be in the traveling backwards group for a bit, if that’s ok.

Comments are closed.