NASA's Curiosity is getting ready for its first taste of Martian soil.

The rover is in position and engineers are preparing the on-board instruments to take the first scoop of soil, the space agency said Thursday.

The samples will then be analyzed to assess whether the Red Planet was ever favourable for microbial life.

"We now have reached an important phase that will get the first solid samples into the analytical instruments in about two weeks," Michael Watkins, mission manager of NASA's Jet Propulsion Laboratory, said in a media release.

'Rocknest' testing site

Earlier this week, Curiosity pulled up to a windblown and sandy area NASA has dubbed Rocknest. The 2.5-by-five-metre patch, where the rover will perform soil tests and analyses, will provide a large surface for scooping several samples.

There are also diverse rocks nearby that Curiosity can investigate.

On Wednesday, the rover used one of its wheels to scuff the soil to expose fresh material.

Next it will use a motorized, clamshell-shaped trowel — one of several tools on the end of its robotic arm — to scoop up a bit of dirt.

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A patch of windblown sand and dust is the Rocknest site, the location for first use of the scoop on the arm of NASA's Mars rover Curiosity. (NASA/JPL-Caltech/MSSS)

The first two samples won't be analyzed, but instead will be used to rinse out the equipment. The rover will shake the soil inside its sample-processing chambers to scrub the internal surfaces.

This "rinse-and-discard" cycle ensures quality control over the samples.

"We want to be sure the first sample we analyze is unambiguously Martian," said Joel Hurowitz, a sample scientist on the Curiosity team.

"So we take these steps to remove any residual material from Earth that might be on the walls of our sample handling system."

The third and fourth scoops will be divided among Curiosity's analytical instruments.

A portion will be delivered to CheMin, a device that identifies and measures mineral composition.

Another portion will go to an instrument called the Sample Analysis at Mars, or SAM, which examines chemical makeup. In particular, it will look for hydrogen, oxygen, nitrogen and carbon — elements associated with life.

Once it has finished its work at the Rocknest site, Curiosity will head about 100 metres eastward to an area called Glenelg, where it will select a rock to begin drilling.

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This drawing shows the internal chambers of the Collection and Handling for In-Situ Martian Rock Analysis (CHIMRA) device, attached to the turret at the end of the robotic arm on NASA's Curiosity Mars rover. Samples from the drill enter via the sample transfer tube, and samples from the scoop enter from the location shown at bottom. The pink line shows the path samples travel from the scoop (in red) to the 150-micrometre sieve (green rectangle) to the portion box (yellow), where they are then delivered to the analytical lab instruments. (NASA/JPL-Caltech)