After four years of sending amazing images and analytic data back to Earth, the Mars Curiosity Rover has now been granted permission to fire its onboard laser without direct human control. The laser, called ChemCam, gives the rover the ability to vaporize Martian rocks in order to analyze their composition.
According to a NASA press release, the ChemCam laser has been an integral part of the data Curiosity has collected about the chemical composition of the Martian landscape:
During Curiosity's nearly four years on Mars, ChemCam has inspected multiple points on more than 1,400 targets by detecting the color spectrum of plasmas generated when laser pulses zap a target -- more than 350,000 total laser shots at about 10,000 points in all.
The ChemCam laser works by analyzing the spectrum of light emitted when rocks or soil samples are vaporized by its powerful pulses of protons, a technique known as laser spectroscopy. The laser cannon also features an extreme high-definition camera that provides further Martian geologic data about the laser’s targets.
The rover's autonomy depends upon a special software package known as AEGIS - Autonomous Exploration for Gathering Increased Science. The software uses visual data gathered by Curiosity to make inferences about the rover’s environment; certain colors or sizes of rocks will cause Curiosity to automatically select them for a good ol’ fashioned lasering.
Giving Curiosity autonomy to choose its own laser targets will allow the rover to continue to collect and analyze data even when communications satellites are out of range or busy with other tasks. JPL engineer Tara Estlin stated in the NASA press release that the autonomy software will greatly accelerate Curiosity's data gathering mission:
Due to their small size and other pointing challenges, hitting these targets accurately with the laser has often required the rover to stay in place while ground operators fine tune pointing parameters. AEGIS enables these targets to be hit on the first try by automatically identifying them and calculating a pointing that will center a ChemCam measurement on the target.
Curiosity is the fourth NASA-built rover to be sent to the red planet since 1996. Its deployment has provided an unparalleled level of the Martian terrain, thanks in large part to the speed with which ChemCam can gather and analyze data. And as an added bonus, if any unruly Martians show up to vandalize poor Curiosity, ChemCam can provide data about how those pesky Martians feel about green laser blasts straight to their Martian faces.