Six men who were locked in total isolation for 520 days to simulate a mission to Mars returned to normal life on Friday.
For 17 months their routine has mirrored that of a real spaceship but they were in a warehouse in a suburb of the Russian capital Moscow.
The three Russians, two Europeans and a Chinese national communicated with the outside world with a delay of 20 minutes - just as they would on a voyage to the Red planet.
The project was aimed at testing how their minds and bodies would cope on a long-haul spaceflight.
They are now in quarantine for three days.
During their ''mission'', the men were fed on rations like those of real astronauts, rarely showered, and had daily urine and blood samples taken while under 24-hour surveillance everywhere but in the toilets.