It's the stuff of fantasy: space agency offers simulated trip to Mars

Are you European or Canadian, aged between 25 and 50, in good health and ready for a unique challenge? The European Space Agency is offering 12 volunteers the most unusual and exotic opportunity of a lifetime: an 18-month simulated mission to Mars.

Despite the gruelling physical and mental trials that participants will face, the Paris-based ESA has been inundated with applications, receiving more than 2,000 in the past two days alone. The project manager, Jennifer Ngo-Anh, described the response as "overwhelming", insisting such a large response was essential to ensure suitable volunteers were found, and admitting "it will be hard to find exactly those people who fit the profile".

The volunteers' profile is understandably restrictive. However, with an application deadline of 30 September, the ESA is expected to receive tens of thousands to choose from.

While the full-length trial will begin in spring 2008, not all of those selected will make it to the final 18-month mission, which will have a crew of just six. Those six will take part in two pilot studies of 100 days each, which will precede the main mission.

During the simulated mission, known as Mars500, the crew will be put through the scenarios they would encounter if genuinely travelling to the Red Planet; including a simulated launch, exploration phase, and long journey home.

Hopeful applicants will be subjected to the same selection procedure as genuine astronauts, with medical expertise and engineering skills valued highly, yet there will be a slightly greater emphasis on mental suitability than physical fitness. The crew's diet will also be identical to that of astronauts onboard the International Space Station, largely consisting of freeze-dried food.

Enclosed within a special isolation facility in Moscow, participants will be observed by psychologists keen to ascertain the impact of such seclusion upon mood and mental health. Differences in personality type, cultural background and crew composition will also be monitored, in an effort to ensure the most suitable astronauts are selected when planning a genuine mission.

The plans have prompted criticisms that the project is really just a latest high-tech reality TV show, a claim that the ESA rejects, insisting it is "a serious scientific experiment". The agency also highlights the fact that the mission is unlikely to prove lucrative for participants, who will only receive basic fees for taking part.

In addition to studying the psychological effects of a trip to Mars, the ESA will be working closely with doctors from the Russian Institute for Biomedical Problems (RIBP), who will be investigating the best way to treat disease and handle illnesses when thousands of miles from Earth.