Mars 500 Over

http://www.guardian.co.uk/science/2013/jan/07/fake-mission-mars-astronauts-spaced-out

http://www.telegraph.co.uk/science/space/9786070/Mars-500-simulated-mission-results-reveal-problem-of-sleep-deprivation-for-astronauts.html

I'm getting sleepy just reading about it! :)