PARIS - If you have planetary vision, want to be on the cutting edge and don't get bored easily, the European Space Agency may be looking for you. It is looking for 12 volunteers for a simulated mission to Mars that will last up to 520 days in "extreme isolation and confinement."

Despite the rigorous conditions, more than 2,000 applications have been received in two days, project manager Jennifer Ngo-Anh said Thursday.

"The reaction has been really overwhelming. My mailbox is full," she said in a telephone interview.

Candidates must be citizens of one of 15 European countries or Canada, be highly motivated and speak English and Russian, among other requirements.

Unlike the adventurous spirits attracted to the desert island prospects of reality TV, only the "serious" need apply for this simulated interplanetary voyage, the space agency said. The payoff is likely less glamorous, too. Remuneration is "in line with international standards" for clinical studies, is all it would say.

The Paris-based agency, known as ESA, is working on the Mars500 project with the Institute for Biomedical Problems in Moscow and the simulated mission will be conducted there and include Russians. The Russian participants will be chosen separately in Russia.

The volunteers will investigate the "human factor" of a trip to the Red Planet -- "a journey with no way out once the spaceship is on a direct path to Mars," ESA says.

The experiment will emphasize psychological factors, including stress resistance. The goal is to test how the volunteers hold up in nearly a year-and-a-half of close confinement, in cramped quarters with others and when communications with Earth can take 20 minutes to reach their destination -- each way.

The simulation is to take place in a series of connected modules, mimicking life in a spacecraft on a trip to Mars, including once it has landed on the planet. The routine includes scientific experiments.

It doesn't include full-time weightlessness, however. "Except for weightlessness and radiation, the simulations will be as close to a real Mars mission as possible," the ESA said in its call for candidates.

The living quarters will include 30-square-foot rooms for each crew member, a kitchen-dining room, living room -- and one toilet. No shower is included, and water supply will be limited.

Food will be "predefined and carefully rationed," the ESA warns. Smoking and drinking is not allowed.

Special training that precedes the simulations will be as similar as possible to that given to astronauts, said Ngo-Anh.

Not all volunteers will have to take part in the final 520-day simulation, which will have a crew of six: four Russians and two Europeans or Canadians. But two pilot studies of about 100 days are to precede the big one. With two volunteers in each of the three projects, plus backups, a full dozen are needed, ESA says.

Launch date for the first of the shorter simulation voyages is mid-2008, and late 2008 or early 2009 for the full simulated trip to Mars.

ESA has a history of carrying out isolation studies, but this is the longest by any space organization, officials said. The agency, with 17 member states, has also carried out confinement studies in the name of space science -- like confining a group of women volunteers to bed for 60 days in 2005.

Calls for candidates for the Mars mission went out Tuesday. By Thursday afternoon, Ngo-Anh, speaking from ESA's Science and Technology Center in the Dutch town of Noordwijk, said she had received over 2,000 applications. That's a good thing, she added.

"It will be hard to find exactly those people who fit" the profile, Ngo-Anh said.

Candidates must be 25 to 50 years old, in good health with work experience in one of several scientific fields, such as medicine, biology, computer engineering or mechanical engineering, the application says. Citizens of Austria, Belgium, Switzerland, Germany, Denmark, Spain, France, Greece, Italy, Ireland, Norway, the Netherlands, Portugal, Sweden, Britain and Canada will be considered.

What if something goes wrong in the living module that the medical module can't help resolve?

"Every crew (member) can leave the tank at any point in time without giving reasons," said Ngo-Anh said. "But by our selection process, we try to find those candidates likely to endure the whole mission."

Potential candidates have all summer to make up their minds whether to apply: The deadline is September 30.