The robot, which is analysing rock samples on the Red Planet, is now running from a back-up computer.

BBC: Mars rover

Once it has landed in Kazakhstan, the three rock samples will be recovered to see how they have fared.

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The timing of the glitch would frustrate Nasa as Curiosity had just begun analysing rock samples, the BBC's science correspondent, Jonathan Amos, said.

BBC: Mars rover

Not wanting to damage the holes themselves, they used a chisel to chip away rock samples from a chimney-like tunnel that connects two of the depressions.

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When they get back, the space vehicle will hopefully have provided enough data to pinpoint a potential drilling area so it can drill, collect and analyze rock samples using onboard tools -- a feat never-before attempted on Mars.

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Curiosity will use a drill and scoop, which are located at the end of its robotic arm, to gather soil and powdered samples of rock interiors, then sieve and parcel out these samples into the rover's analytical laboratory instruments.

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To address these outstanding questions, the team will collect samples of rock to date their exposure to cosmic radiation and analyse how glaciers and ice have retreated since the last ice age, around 20, 000 years ago.

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