why space travel can get really, really boring

A simulated mission to Mars finds that one of the biggest potential threats to astronauts outside of radiation will be cabin fever.

After spending over 500 days in a simulated spacecraft, a small group of volunteers gave us a worrying peek into the future of space exploration. If astronauts of the near future will have to spend nearly two years locked up in an equivalent of a small space-faring submarine, the best case outcome is boredom, lethargy, and weight gain. Day after day with nothing to do but sit in a metal capsule zooming through space can really take its toll on sleep patterns and could quickly turn into a serious case of cabin fever. Here on Earth it's not that big of a deal. But in space, an outburst from a crew member could have very serious consequences. Flying to Mars with a very angry and depressed pilot slowly but surely going stir crazy is no one's idea of a good time, and no amount of sweet talking from mission control tens of millions of miles away is likely to help. If anything, adding the very real element of extreme isolation from humanity would make things a lot worse, making a stressed astronaut feel more like a prisoner than an explorer.

So what do we do? Give them lots of movies, video games, and experiments to perform? As the study shows, that won't be enough. You can only play so many games and watch so many films, and in a confined space, only so many experiments can be carried out and only for very limited stretches of time. We could say that in the Mars 500 study the volunteers had no critical tasks to perform and that the astronauts would busy themselves with maintenance. However, it's not very likely that the astronauts would perform a lot of EVAs or simply take over tasks that would have to be done by machines during the trip so there would be little in the way of stretching your legs or extensive work with which to occupy your mind. Even worse, the artificial environment would disrupt the crew's circadian rythms and each crew member would have a different reaction. One of the volunteers in the Mars 500 study was so affected by the lack of a natural cycle, he often slept while most of the crew were awake and was awake when they were asleep, something the researchers identified as a possible start of a nasty argument on a real mission.

Ok, so video games, movies, and busy work aren't enough to keep everyone sane and on task during a multi-year mission. Are there any real solutions to this problem? Well, the easiest one would be to find people particularly well suited for keeping themselves busy or comfortable with unchanging routines for many months on end. Another would be to deploy a combination of LED lights and other environmental cues to keep the astronauts sleeping and waking on a cycle their bodies would find comfortable. Personally, I would vote for a larger ship and a bigger crew, like a floating colony where there would be plenty of room to stretch and things to do, powered by the kind of VASMIR plasma engines that could get it to Mars within a few months. Active social lives, a shorter trip, and ample room would make for a very expensive mission, but they would also be a boon to the astronauts who would be happier and better mentally prepared for exploring an alien world. Because if they're as lethargic and mentally spent as the Mars 500 subjects or fare even worse, it's doubtful that the mission would meet all of its objectives and that we won't have glaring and dangerous mistakes that could easily jeopardize the lives of the whole crew.

See: Basner, M., et al. (2013). Mars 520 mission simulation reveals protracted crew hypokinesis and alterations of sleep duration and timing PNAS DOI: 10.1073/pnas.1212646110