A trip to Mars, with its invisible technology and vast, unprecedented distance from home, could estrange or alienate a crew to an unprecedented degree. Such a distance could produce an entirely new kind of boredom, impossible to imagine on Earth.
http://aeon.co/magazine/being-human/what-four-months-on-mars-taught-me-about-boredom/
The Mars simulation we’re setting up is called Hawaii Space Exploration Analog & Simulation or HI-SEAS. It’s primarily a food study. One of the main problems during long-term space travel is so-called menu fatigue. It’s basically astronauts getting tired of their food and losing appetite. By the way astronauts do not eat out of tubes and do not swallow food pills. That’s an old persistent cliché which is still in a lot of people’s minds. It’s almost an archetype of astronaut life. However this dates to the ’50s and ’60s, and has been long abandoned. The food that astronauts currently eat is pretty good, but it’s all pre-prepared. It’s add-water-and-heat, and you have your meal. But even those meals, even when they try to make variations, after a couple of months people get tired of that, and so they start to eat less. As a consequence they might also perform less, and jeopardize the mission.
http://blog.ted.com/2013/03/22/spatzle-in-space-fellows-friday-with-angelo-vermeulen/