杏吧原创

Update on 14 February: Two crew members made their first 鈥淢ars walk鈥� on the 10-metre-long by 6-metre-wide simulated Martian surface at 1300 Moscow time. It lasted for one hour and 12 minutes. The next Mars walk will occur on 18 February.

YOU could say it鈥檚 the biggest 鈥渟mall step for mankind鈥� ever made. Three people are poised to make the first mock landing on Mars.

In the most realistic simulation of a mission to the Red Planet yet, six 鈥渁stronauts鈥� have been isolated for eight months in a facility here on Earth. The experiment will ultimately last twice as long 鈥� 520 days in total 鈥� similar to the length of a real Mars mission. The hope is that the experience will hold useful lessons for a future journey to Mars.

The Mars500 experiment began on 3 June, when crew members were closed inside a mock spaceship at Russia鈥檚 in Moscow, which is leading the project (see diagram). Three of the crew are Russian, one is Italian, one French and one Chinese. All six are men, though women were not deliberately excluded, says Jennifer Ngo-Anh, the European Space Agency鈥檚 Mars500 project manager. 鈥淚t just so happened that we didn鈥檛 find suitable female candidates,鈥� she says.

The mission is approaching its biggest milestone: the landing itself. The 鈥渟pacecraft鈥� entered orbit around Mars on 1 February. On 12 February, a 鈥渓anding craft鈥� containing three of the crew will touch down. Over the course of the next 10 days, they will leave the craft in pairs for three sorties to explore the planet鈥檚 surface 鈥� in reality a room with a high, domed ceiling and a floor covered in reddish sand and rocks. They will wear space suits and will also deploy a remote-controlled rover.

The next day, the explorers will 鈥渞ocket鈥� back to Mars orbit to rejoin the three astronauts who stayed behind. They will then spend eight months or so travelling back to Earth, with the mission ending on 5 November 2011 (see timeline).

So will this pretend mission produce any useful data? After all, the participants will not experience reduced gravity or the dangers of rocket launches and space radiation. If the going gets rough, the crew members can walk out of the experiment at any time.

of the University of Pennsylvania in Philadelphia, who is studying the crew鈥檚 psychological responses to isolation, says the experiment shares enough similarities with a real Mars mission to provide helpful insights.

The experiment also provides an opportunity to obtain psychological information all the way through a mission. Records from actual space missions are much more piecemeal. 鈥淲hat we have is largely post-hoc anecdote,鈥� Dinges says. 鈥淲e don鈥檛 have this kind of objective measurement of neuro-behavioural function across a mission, and that鈥檚 what we鈥檙e after.鈥�

Crew members answer questionnaires about feelings of tension and conflict, and detectors strapped to their wrists record their movements to show, for example, when they are sleeping. Their faces are videotaped while they are working on the computers so their expressions can be analysed for signs of fatigue, stress and depression.

Dinges says the observing researchers have already recorded plenty of interesting data. 鈥淲e鈥檙e more convinced than ever that this is going to be very useful,鈥� he says. The results are being kept under wraps until the experiment is over to prevent any information leaks from influencing the crew鈥檚 behaviour. The crew communicates with the outside world by exchanging messages with mission control.

As part of the simulation, a delay of up to 20 minutes has been added to simulate the time it takes for light to travel to Mars. By contrast, astronauts on the International Space Station (ISS) are close enough to Earth to communicate in real time with family and friends on the ground.

If entries and (see 鈥淭witter from 鈥榮pace'鈥�) from crew members are anything to go by, boredom is the biggest problem. On Halloween, for example, they made a great show of decorating the craft and dressing up. 鈥淪ome of us kept the costumes on all day, even while we worked on our usual science and housekeeping tasks,鈥� writes crew member Diego Urbina. 鈥淲ang Yue, unfamiliar with this western celebration, asks if we are always this excited about Halloween, we tell him not usually: but in here, it is just a great excuse to change the routine 鈥� even for just one day.鈥�

The next step in preparing for a Mars mission would be a simulation that involves going into space, says of the University of California in San Francisco, who is not involved in the experiment. 鈥淢ars500 is a wonderful first step, but it鈥檚 not a perfect simulator,鈥� he says.

He suggests sending astronauts on a long-duration mission to the moon, with lengthy stays aboard the ISS to simulate the transit time to and from Mars. That would overcome some of Mars500鈥檚 limitations, such as the lack of microgravity, he says.

Such a project is likely to be a long way off, however. In the meantime, Mars500 should help us learn how to plan a mission to Mars, Ngo-Anh says. 鈥淲e can prepare and improve the technology, but at the end it will be the human factor 鈥� the crew 鈥� who decide whether the mission will be a success,鈥� she says.