The sleep experiment is among the first to show what each crew member went through during their simulated mission.

BBC: Sleep problems could jeopardise future missions to Mars

We flew a simulated mission within a grounded duplicate of the flyable F-35 cockpit, and the capabilities and improvements are quite clear -- you definitely don't want to encounter an F-35 from a previous-generation aircraft.

ENGADGET: Lockheed Martin F-35 Lightning II stealth fighter cockpit demonstrator hands-on (video)

There were many aspects of a real mission that could not be simulated in a Moscow suburb, of course - such as weightlessness and the dangers associated with space radiation.

BBC: Simulated Mars mission 'lands' back on Earth