Concerns over the psychological toll brought on by long periods of isolation have dominated the spaceflight conversation from the beginning. The first episode of "The Twilight Zone," titled "Where is Everybody?", focused on this very topic, and CBS broadcast it in October 1959 -- more than a year and a half before Yuri Gagarin became the first human in space.
Isolation and confinement: The two inescapable realities that set the lives of astronauts, polar explorers, mountain climbers and submariners apart from ours, and they make all the difference.
That's why the Russian and European space agencies devoted more than $15 million to Mars500, an experiment that tested the psychological reactions of six men on a simulated spaceship to Mars.
The three Russian, one Italian, one French and one Chinese participant spent 520 days (17 months) locked in a windowless, 2,150-square-foot (200-square-meter) assembly of connected metal tubes. During their stay, they maintained communications with Earth, complete with simulated 20-minute transmission lag, each way -- a trompe l'oreille that participants admitted fooled their minds into believing mission control lay millions of miles away instead of just across the parking lot. The mission length equated to a trip to Mars, a four-month stay and a return flight [sources: Chao; Chow; de Carbonnel].
Over the course of the study, the mock crew performed 100 experiments and repetitive tasks, while also reacting to simulations of likely events. The facility included a fake Mars rover and a 33-by-20-foot (10-by-6-meter) mockup of Mars so that participants could simulate "Mars walks" in full gear. Like the cast of a deranged reality show, the six remained under near-constant surveillance [sources: Chow; de Carbonnel].
Mars500 wasn't the first attempt at an isolation simulation, although it was the longest. In 2000, a 420-day experiment by the same Russian facility devolved into an alcohol-fueled fistfight and a sexual assault and was stopped. Previous studies also demonstrated an increase in boredom and depression during the trip's "return" stage [sources: Chow; de Carbonnel; Roach]. As of April 2012, NASA was considering setting a mock Mars mission on the International Space Station, to factor in the effects of microgravity [source: Moskowitz].
After the Mars500 mission ended on Nov. 4, 2011, psychologists expressed concern that the din and bustle of ordinary life might prove somewhat overwhelming to the participants [sources: Chow; de Carbonnel].
Such experiments raise the question: Are we the problem? Astro- and aeronautical engineers probably think so, and the space program has long struggled to balance mission parameters with crew health and welfare.
So, what if the solution isn't to make a better ship, but to build a better ... us?