The European Space Agency (ESA) on Friday named a Frenchman and a German who will join four Russians in an innovative 105-day isolation experiment to test whether humans can one day fly to Mars.
From March 31, the six "crew" will be locked inside a special facility in Moscow that replicates conditions of a space trip to Mars.
The simulation will be followed by a 520-day experiment, starting later this year, that would last as long as a real mission to Mars.
The two Europeans are Oliver Knickel, 28, a mechanical engineer in the German army, and Cyrille Fournier, 40, a captain with Air France who flies A320 airliners, ESA said in a press release.
The distance between Earth and Mars varies between 55 million kilometres (34 million miles) and more than 400 million kms (250 million miles).
Using current rocket technology, a there-and-back trip to the Red Planet would take at least 18 months.
Maintaining the crew's mental and physical health is deemed by space scientists to be as challenging as gathering the money and technical resources for the historic trip.
The six guinea pigs will be scrutinised for stress, mood, hormone regulation, immune defences and sleep quality.
Researchers also want to know whether dietary supplements will sustain their health.
The simulation will include all the main elements of a simulated Mars mission, including travelling to Mars, orbiting the planet, landing on its surface and returning to Earth, ESA said.
"The crew will only have personal contact with each other, plus voice contact with a simulated control centre and family and friends," it said.
"A 20-minute delay will be built into communications with the control centre to simulate an interplanetary mission and the crew will eat the same food as the astronauts on the International Space Station."
The project is a joint venture between ESA's Directorate of Human Spaceflight and the Russian Institute for Biomedical Problems (IBMP).
ESA and NASA have separately sketched dates around three decades from now for a manned flight to Mars.
(c) 2009 AFP
Explore further: Researchers find giant convection cells on the Sun