Back in August, we told you about the Mars500 mission - a simulated space journey to the red planet, in which an international crew of six spent 520 days in isolation in a Russian parking lot to replicate the conditions of a real manned mission to Mars. Well, the 520 days have passed, and they've "landed" back on earth.

According to psychologists, the experiment put the team members under stress as they grew tired of each other's company. Their mission was the longest imitation space flight ever attempted, after all. Still, the crew members were smiling when they left their windowless "space module" to speak to a press conference. Italian-Colombian crew member Diego Urbina said he and his teammates were proud of their work, and that they hope "humankind can one day greet a new dawn on the surface of a distant but reachable planet".

It might be a few years yet before people actually make it to Mars - NASA says it's aiming for the 2030s - but a rover called 'Curiosity' is there right now. And there's a Canadian connection: the rover is carrying an instrument called an Alpha Particle X-Ray Spectrometer (APXS) that was provided by the Canadian Space Agency (CSA). If a manned mission to Mars ever becomes a reality, the APXS will help scientists work out how to make the planet inhabitable. Because after 520 days in a spacecraft, the crew will probably want to stretch their legs.