June 8, 2015

ChemCam et SAM Instruments on NASA’s Curiosity rover get very-long-distance fixes

Since August 2012, for nearly 1,000 Mars days, NASA’s Curiosity rover has been pursuing a unique scientific and technological adventure on the surface of the Red Planet. During this time, its systems have been subjected to the rigours of Mars’ climate. The rover’s ChemCam and SAM instruments recently received fixes 350 million kilometres from Earth to restore them to full operational capability, working with teams in France.

The ChemCam instrument’s quick auto-focus capability has been restored. Six months ago, teams in charge of operations at the Jet Propulsion Laboratory (JPL), Los Alamos National Laboratory (LANL) and French teams at CNES, CNRS and Pierre et Marie Curie and Paris-Sud universities had to deal with a component glitch that forced them to switch from auto-focus to a much slower manual focusing mode to be able to continue their analyses with ChemCam. At the same time, they began working on a better solution that has just been successfully installed, consisting in rewriting the instrument’s software code to use images taken by ChemCam to automatically focus its laser. On 5 May, the new code was uploaded to the rover 350 million kilometres away, and on 11 May analysis of the first data revealed that the fix was a great success, restoring ChemCam to full operational capability. It has already fired its laser some 250,000 times on Mars.

The rover’s SAM instrument also experienced some glitches early this year as a result of its repeated analyses and natural ageing of its components. The gas flow in chromatography column n°5, the most used with 27 analyses, began to vary abnormally, leading to the partial loss of data from an analysis of Mars soil. Scientists and engineers on the French SAM team worked with their counterparts at NASA’s Goddard Space Flight Center (GSFC) to devise diagnostic and anomaly resolution sequences, which they subsequently uploaded to the rover. Data received from Curiosity on 11 May showed that SAM has also been restored to full operational capability.

Meanwhile, Curiosity’s scientific exploration of Mars continued. The rover spent eight months at an outcrop known as Pahrump Hills, which marks the transition between the plains of its crater landing site and the foothills of Mount Sharp, its final destination. This region revealed further evidence of past aqueous activity, only in environmental conditions different to anything the rover had seen previously. The composition of rocks there suggests that more-acid chemical conditions once existed. ChemCam, SAM and Curiosity’s other instruments are continuing to catalogue the varied sediments in these rocks. Curiosity recently set out for the exposed strata of Mount Sharp, driving through a series of canyons containing interesting outcrops. It has now driven more than 10 kilometres on the surface of Mars. It was forced to suspend operations for three weeks starting on 7 June, as Mars is now on the opposite side of the Sun, making communications with Earth impossible.

The Mars Science Laboratory project, spearheaded by the Curiosity rover, was developed and is operated by JPL (Caltech) on behalf of NASA. The LATMOS atmospheres, environments and space observations laboratory (CNRS/Pierre et Marie Curie University, Versailles Saint-Quentin University) and the LISA inter-university laboratory for the study of atmospheric systems (CNRS/Paris-Est Créteil University/Paris-Diderot University) supplied the gas-phase chromatograph, one of the three instruments composing the SAM suite, and is co-principal investigator (Co-PI) with GSFC in Maryland, USA. The IRAP astrophysics and planetology research institute is Co-PI for the ChemCam instrument with LANL in New Mexico, USA. CNES personnel and French research scientists are operating these two instruments on the surface of Mars in real time from the French Instruments Mars Operations Centre (FIMOC) at CNES in Toulouse.

Pascale Bresson    Tel. +33 (0)1 44 76 75 39    pascale.bresson@cnes.fr
Alain Delrieu    Tel. +33 (0)1 44 76 74 04    alain.delrieu@cnes.fr
Julien Watelet    Tel. +33 (0)1 44 76 78 37    julien.watelet@cnes.fr

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