Astronauts prepare for 'Mars mission'

Six astronauts are preparing to spend 520 days together in a sealed-off complex to simulate the rigours of a mission to Mars.

Mars500 is a simulated trip to the red planet to test how long it takes for isolation to affect humans.

Three Russians, an Italian-Colombian, a Frenchman and Chinese astronaut will be locked up in a set of cramped compartments in Moscow and will not be released until November 2011.

The six men will be allowed just three square metres of personal space per person and will live and work like astronauts, with maintenance tasks, scientific experiments and daily exercise.

Last year four Russians, one German and a Frenchman successfully completed a 105-day simulated trip to Mars.

Like them, this crew will be monitored closely, and psychological and physiological data will be recorded during the mission.