This 15 September is the 105th day for the "Mars 500" crew, meaning they have now passed as much time in isolation than the previous experience conducted last year to prepare for this simulation of a journey to Mars.
Since 3 June a crew of six, including two Europeans, is inside a spacecraft mockup at the Russian Institute of Biomedical Problems (IBMP) in Moscow.
This experiment is planned to last 520 days, as long as a real trip to the red planet.