On Sunday, August 19, the Mars Science Laboratory (MSL) rover Curiosity used its mast-mounted science laser for the first time. Mission controllers at the NASA Jet Propulsion Laboratory (JPL), in Pasadena, California, say that the test occurred flawlessly.
The target was a small rock called Coronation, which lies near the 1-ton robot's landing site. The object was hit with 30 laser pulses over a period of 10 seconds, and the resulting vaporized material was then studied in detail.
This laser is a part of the MSL Chemistry and Camera (ChemCam) instrument, which is installed on the rover's mast. The light source is capable of delivering 1 million watts of power for very brief intervals, of just five one-billionths of a second.
When this energetic light beam hit Coronation, it excited some of its atoms to the point where they formed ionized, glowing plasma. ChemCam was then used to analyze this glow, and figure out the chemical composition of the rock itself. The instrument features three spectrometers for such studies.
“We got a great spectrum of Coronation – lots of signal. Our team is both thrilled and working hard, looking at the results. After eight years building the instrument, it's payoff time!” says Roger Wiens, an expert at the DOE Los Alamos National Laboratory, and the principal investigator of ChemCam.
He explains that the instrument recorded spectral readings of each of the 30 plasma flashes the laser produced. Originally devised as a high-tech form of target practice, yesterday's test may actually turn out to provide useful information about Coronation.
An interesting possibility is that the rock may have been covered with dust or other materials. Experts will check to see if the chemical compositions recorded in the 30 plasma flashes changed over time.
If so, the results would imply that each laser pulse penetrated deeper and deeper into Coronation's surface. Checking to see whether that actually happened or not is easy, since ChemCam records 6,144 different wavelengths, from ultraviolet to infrared.
“It's surprising that the data are even better than we ever had during tests on Earth, in signal-to-noise ratio. It's so rich, we can expect great science from investigating what might be thousands of targets with ChemCam in the next two years,” Sylvestre Maurice explains.
The expert, who is based at the Institut de Recherche en Astrophysique et Planetologie (IRAP), in Toulouse, France, is a ChemCam deputy project scientist.
The instrument was built by LANL experts and colleagues from the French national space agency, Centre National d'Etudes Spatiales (CNES) and the Centre National de la Recherche Scientifique (CNRS).