Update to Mars-based major element quantification accuracies from
calibration targets of ChemCam at 3013 sols and SuperCam at 527 sols
The Curiosity and Perseverance Mars rovers include the laser-induced
breakdown spectroscopy (LIBS) instruments ChemCam and SuperCam,
respectively, to assess the chemistry of Mars surface materials. Onboard
calibration targets (CT) are frequently analyzed to check for system
health. Their spectra and predicted compositions are uploaded to the
NASA Planetary Data System (PDS). The ten ChemCam CTs cover limited
compositions, while the 23 SuperCam CTs are more representative of Mars.
This study compares and contextualizes predicted versus actual
abundances of major elements (SiO2, TiO2, Al2O3, FeOT, MgO, CaO, Na2O,
and K2O) in the CTs. For both instruments, Mars-based calibration
accuracies differ from PDS-reported values: Curiosity on-Mars errors are
equivalent or better than lab values but from CTs with limited scope.
Perseverance has poorer Mars-based accuracies than expected in the lab,
but CTs are diverse. Results over time reveal that CT surfaces have not
degraded and Mars-based calibration accuracies are mostly reproducible.