Six men have a completed a mock mission to Mars.

The 520-day experiment was designed to simulate confinement, stress and
fatigue of interplanetary travel.

They've spent a year and a half locked in a windowless module in Moscow.

They ate canned food similar to that offered on the International Space
Station.

And communicated with their families via an internet connection which was
regularly delayed and disrupted to imitate the effects of distant space travel.