The all-male crew of three Russians, a Chinese, a Frenchman and an Italian-Colombian has been inside windowless capsules at a Moscow research center since June. Their mission aims to help real space crews in the future cope with the confinement and stress of interplanetary travel. The six men are due to "land" on Mars on Feb. 12 and spend two days researching the planet. They then begin the months-long return flight to Earth, expected to be the most challenging part of the mission. In an effort to reproduce the conditions of space travel, with exception of weightlessness, the crew has living quarters the size of a bus connected with several other modules for experiments and exercise. A separate built-in imitator of the Red Planet's surface is attached for the mock landing.