Curiosity has gotten smarter: the Mars rover now has the capability to select ChemCam laser targets autonomously, allowing the four year-old prospector to choose its own targets for remote evaluation.
ChemCam has been a godsend for qualifying geological targets for closer evaluation by the roving laboratory. It can also provide remote analysis of interesting formations that cannot be physically reached by the rover—for instance, something too high or beyond an obstacle that the rover drivers do not want to risk crossing.
ChemCam—short for Chemistry and Camera complex—consists of a high-powered laser that operates in conjunction with a telescopic spectrometer mounted on Curiosity’s camera mast. This technique is called LIBS, for Laser-Induced Breakdown Spectroscopy. The laser can be fired at targets up to about 25 feet away, and in the brief moment that a plasma is formed by the extreme heat from the laser, the spectrometer can extract information about the elemental composition of the rock or other target area.
ChemCam has greatly expanded the rover’s capability to explore areas otherwise unavailable to Curiosity, and has saved a lot of time by allowing scientists to take a chemical snapshot of an interesting target in order to decide if it merits further, closer investigation by contact tools, such as those on the end of the robotic arm. These include optical instruments for microscopic imaging, the Alpha Particle X-ray Spectrometer and sample gathering for evaluation within Curiosity’s onboard lab.
This new capability will allow Curiosity to select targets autonomously, first identifying a promising rock formation, for example, using software with criteria specified by the science team, and then firing the laser and recording the analyses for future transmission to Earth. This is particularly useful when the rover is making a long drive and is not in contact with controllers at JPL, or is otherwise out of contact due to the Mars orbiters that are used to relay information being out of range.
Since it began operation in 2012, Curiosity has used the ChemCam laser method over 1400 times with 350,000 laser bursts. The newfound autonomy should cause the rate of ChemCam investigations to rise appreciably.