In January 2021, the ChemCam instrument on board the Mars Curiosity rover sent state-of-health data indicating that the high voltage (HV) required for firing the laser was not as stable as usual. ChemCam has been operating on Curiosity since the rover landed on Mars in 2012. The laser was still firing normally and the returned spectral data were normal, but laser operations on Mars were paused to investigate. During this time, ChemCam continued to obtain image and passive spectroscopy data.
The leads for the laser in France populated a spare electronics board nearly identical to the one on Mars and spent several weeks testing various modes that might cause some instability. They found that the HV behavior was no risk to the rest of the instrument.
The team decided to test several laser operational modes on Mars to determine how to best restart laser operations. Testing on Mars with ChemCam has shown that the HV remains relatively stable when the instrument is cool; the laser continues to fire normally and return excellent science data. Moving forward, the ChemCam team will continue the use of the laser but will limit the total number of laser activities planned at a single time to maintain cooler instrument temperatures.
“This return to normal laser operations represents an enormous effort from the team to respond rapidly to find a solution,” said Nina Lanza, principal investigator of ChemCam. “The ChemCam instrument has thus far returned over 880,000 individual spectra (each representing a single laser shot) from 3,000 different targets, and more than 16,000 images. It will continue to add to this impressive data set as the Curiosity mission continues—which is exciting news for all of us.”