The BBC reports that six volunteers have begun a planned year-long stint "without fresh air, fresh food or privacy"
in a NASA simulation of what life might be like for a group of Mars colonists. The volunteers are to spend the next 12 months in the dome (11 meters in diameter, 6 meters high), except for space-suited out-of-dome excursions, where they will eat space-style meals, sleep on tiny cots, and keep up a science schedule. The current mission is the fourth (and longest yet) from the Hawai'i Space Exploration Analog and Simulation
; you can read more about this mission's crew here