Near is the first Nasa planetary mission controlled by a non-Nasa space centre .

BBC: At a glance: Asteroid touchdown

The rocket failures come on top of the loss of Phobos-Grunt, Russia's most ambitious planetary mission in decades.

BBC: Soyuz back in service after failed launch

Rover mission managers named the outcrop as a tribute to Mars scientist Ronald Greeley (1939-2011), who served as a mission team member and taught planetary science at Arizona State University.

MSN: A stunning close-up of Mars taken by visiting NASA rover

Jim Green, director of Nasa's planetary science division in Washington DC, said the extended mission would allow the science community and the public to continue to share in "unlocking Saturn's secrets".

BBC: Nasa extends Saturn probe mission

As many as 100 students may ultimately be chosen for the project, depending on mission constraints, according to a spokeswoman for the Planetary Society, a space-boosting organization that is supporting the venture.

CNN: Space Day 1999

"We have found a habitable environment which is so benign and supportive of life that if you had been on the planet, the water would have been pure enough to drink, " said planetary scientist John Grotzinger, at the California Institute of Technology, who is the mission's project scientist.

WSJ: Scientists Say Microbial Life Was Possible on Mars

This unlikely sounding collaboration is taking place between researchers interested in exploring Lake Vostok in Antarctica, which is sealed off below several kilometres of ice, and planetary scientists, who see such exploration as a possible dress rehearsal for a future robotic mission to Jupiter's moon Europa, whose icy surface is thought to conceal vast oceans that might harbour extraterrestrial life.

ECONOMIST: Planetary pretenders