NASA rover set for third drill on Mars

NASA's Curiosity rover is set to carry out its third-ever drilling into a rock on Mars to collect samples for analysis that may provide clues about life on the red planet.
The rover used several tools to examine the candidate site over the weekend, including a wire-bristle brush - the Dust Removal Tool - to clear away dust from a patch on the rock, NASA said.
The target slab of sandstone has been given the informal name "Windjana," after a gorge in Western Australia.
"In the brushed spot, we can see that the rock is fine-grained, its true colour is much greyer than the surface dust, and some portions of the rock are harder than others, creating the interesting bumpy textures," said Curiosity science team member Melissa Rice of the California Institute of Technology, Pasadena.

"All of these traits reinforce our interest in drilling here in order understand the chemistry of the fluids that bound these grains together to form the rock," said Rice.
Before Curiosity drills deeply enough for collection of rock-powder sample, plans call for a preparatory "mini-drill" operation on the target, as a further check for readiness, said NASA.

Curiosity's hammering drill collects powdered sample material from the interior of a rock, and then the rover prepares and delivers portions of the sample to laboratory instruments on-board.
The first two Martian rocks drilled and analysed this way were mud-stone slabs neighbouring each other in Yellowknife Bay, about 4 kilometres northeast of the rover's current location at a way-point called "The Kimberley."

Those two rocks yielded evidence last year of an ancient lake-bed environment with key chemical elements and a chemical energy source that provided conditions billions of years ago favourable for microbial life.
NASA's Mars Science Laboratory Project is using Curiosity to assess ancient habitable environments and major changes in Martian environmental conditions.