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Mars Mission ReturnsAfter nearly a year and a half, the crew of a European mission to "Mars"—including these two, pictured testing Russian space suits last summer—returned home this morning, stepping out of their capsule to much fanfare in Moscow.In reality, the six men never left Earth. They've spent the last 520 days in a mock spaceship in the Russian capital as part of an experiment to study the psychological effects of deep-space voyages.The Mars500 crew members were physically cut off from the rest of the world and faced with a simulated 20-minute communications delay, to mimic the expected conditions of a real human trip to Mars.(Related: "Why Did 400 People Volunteer for a One-Way Trip to Mars?")The "astronauts" had plenty to do during their voyage: In addition to reading and playing video games, the crew had to conduct experiments on their minds and bodies, repair equipment, and even respond to simulated emergencies-including performing CPR on a mannequin.Halfway through the mission, the crew touched down on "Mars" and tromped around in a sand-filled room, collecting samples and deploying sensors.—Rachel Kaufman

Photograph courtesy Oleg Voloshin, IBMP