For over 500 days, six men will live in isolation, simulating a full-duration flight to Mars.
Six volunteers will be sealed away for one-and-a-half years to simulate a Mars mission.
The experiment, however, won't be able to simulate all aspects of the mission, such as micro-gravity.
A real flight to Mars will not set off before 2030.
The six men who enlisted to be locked up for over 500 days to simulate a mission to Mars called themselves "trailblazers" Tuesday, saying they were ready to face the strain of the isolation.
"We are trailblazers, but while this is very exciting, it brings a certain responsibility. I echo my teammates in saying we will do everything to be successful," Russian volunteer Mikhail Sinelnikov told reporters in Moscow.
The three Russians, two Europeans and one Chinese national will be sealed away for one-and-a-half years inside a 180-square-meter (1,000-square-feet) spaceship module on the outskirts of Moscow starting on June 3.
"It will be trying for all of us. We cannot see our family, we cannot see our friends, but I think it is all a glorious time in our lives," enthused Chinese participant Wang Yue, who is the youngest volunteer at age 27.