NASA's spaceships, satellites and robots have a way of hanging around long after they're due to die. The Spirit rover, which set down on Mars in 2004, was meant to rove for 90 days. It lasted six years. A satellite launched in 1978 just returned from a trip around the Sun—still functioning. So, unless something goes drastically wrong, it's not unreasonable to expect NASA's Curiosity rover to hang around beyond the end of its original mission, which ends this summer. And, if Curiosity can hang around for a few more years, the little lonely robot will get a new friend.
In 2018, the European Space Agency and the Russian Federal Space Agency will be launching a new rover to the red planet. Known as ExoMars, the rover is designed to hunt for signs of life on Mars.
The ESA's Mars rover has been in the planning and design stages since 2002. But now, with the 2018 launch deadline approaching, the team is facing some tough choices. Researchers are meeting in Madrid to try to work out where ExoMars should set down, says Stuart Clark for the Guardian.
As nice as it would be to poke around Mars' polar ice caps, there are some technological details that constrain where ExoMars can go, says Clark:
[B]ecause of the way that we tend to land on Mars, most of the planet is immediately ruled out. All landers use a parachute to slow themselves down as they come through the thin atmosphere. To make sure that the parachute has enough time to do its job, the landers need to touch down at as low an elevation as possible.
Then, to make sure it gets enough fuel from its solar panels, ExoMars has to stick somewhat near the equator. Finding the right balance between technically feasible and scientifically interesting will be tough.
Once ExoMars does touch down, though, says Clark, it will offer a pretty unique look at Mars' past. Whereas Curiosity is bristling with sensors and analytical tools, it really only has a little scoop to scrape at the top of the Martian soil. ExoMars, on the other hand, has a 6-foot drill. In geology, when you go down, you often go back in time—maybe even back to a time when Mars hosted life.