MOSCOW – A manned mission to Mars may be decades away, but an international team of researchers will try to experience what one might be like by locking themselves up in a windowless capsule for a year-and-half — the time needed for a roundtrip to the red planet.

The all-male crew of three Russians, a Frenchman, an Italian-Colombian and a Chinese won’t endure weightlessness, but from today on they will live for 520 days in the spartan conditions of a mock spaceship and follow a harsh regimen of experiments and exercise.

The main task of the Mars-500 experiment is to study the effects of long isolation to help a real space crew of the future cope better with stress and fatigue.

“When everybody interacts with the same people in the same space, habits and behavior become apparent very quickly. These habits may irritate and cause indignation — and even fits of aggression,” said Mikhail Baryshev, a psychotherapist who is connected to the program.

The experiment, conducted by the Moscow-based Institute for Medical and Biological Problems in cooperation with the European Space Agency and Chinese space authorities, will simulate a 250-day journey to Mars, a 30-day surface exploration and 240-day return trip.

The institute in western Moscow is the nation’s premier space medicine center; it has served the Soviet and then Russian space programs since the dawn of the space age. The facility built for the experiment comprises several connected modules with a total volume of about 20,000 cubic feet and a separate built-in imitator of Mars surface for the mock landing.

The researchers will communicate with the outside world via Internet, delayed and occasionally disrupted to imitate the effects of space travel. They will eat canned food similar to that currently offered to astronauts on the International Space Station and take a shower once every 10 days — mimicking space conditions.