Each time, researchers select a six-member crew then challenge them to survive in a solar-powered, uninsulated dome that comes equipped with all the luxuries (or lack thereof) one might find in an actual interplanetary habitat.

The crew enjoyed amenities such as composting toilets, freeze-dried meat, and limited medical supplies (fortunately, no major injuries occurred). They also lived with a 20-minute communications delay with people outside the dome, and personal living spaces smaller than the closets at nearby resorts. Entertainment included rousing rounds of Yahtzee and some reluctant salsa dancing. Crew members recommended bringing a Kindle and a ukulele to combat boredom, among other things.

The mission can’t fully simulate what it’s like to be on Mars—Earth’s gravity won’t cooperate with that, for one thing. (Read about how human visitors will get back off Mars.)

“If you’re the kind of person who can’t really suspend disbelief—who knows there’s air in the airlock, who’s more than happy to walk out that door—you’re probably not the kind of person who would want to come on this mission,” says Andrzej Stewart, the mission’s chief engineering officer. “You have to suspend disbelief a little bit to really get the full experience.”