Give this Guardian article a read. Five astronauts volunteered to be part of a 500-day long simulated mission to Mars.
Nothing in the article is as fascinating as the final sentence:
ESA officials will speak to the crew about their plans for the future once they have settled back into normal life. “They don’t have jobs yet. We didn’t promise anything,” Zell said.
A 500 days exercise in boredom management, cross-cultural relations, and sensory deprivation. They may not have jobs, but they’re going to nail every corporate interview they have!