Trip to Mars in pretend spaceship on Moscow industrial estate affects sleep, activity levels and motivation of six-man crew

The drudge of interplanetary travel has emerged from research on six men who joined the longest simulated space mission ever: a 17-month round trip to the red planet in a pretend spaceship housed at a Moscow industrial estate.
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According to the study, published in Proceedings of the National Academy of Sciences, some crew members fared worse than others. One began living a 25-hour day, and quickly fell out of routine with the others. "If you live on a 25-hour day, after twelve days it's the middle of the night for you when it's daytime for everyone else," Basner said.

Another crew member slept at night but took ever longer naps during the day. Taken together, the two men spent a fifth of their time, or 2,500 hours, asleep when the rest of the crew were awake, or vice-versa. "That cannot be good for mission success, because mission-critical tasks will be scheduled for the day," Basner said.

A third crew member slept so badly he suffered chronic sleep deprivation and single-handedly accounted for the majority of mistakes made on a computer test used to measure concentration and alertness. "He was falling apart in terms of his attention system," Basner said. In a second study, not yet published, the team describes a fourth crew member who was developing mild depression.

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