This summer, NASA will send a new laser-equipped rover to the surface of Mars. Unlike science fiction lasers, the laser on the Mars2020 rover is used to study the geology of the ground from a distance of seven metres and will be able to help scientists in their search for early signs of fossilized microbial life on the Red Planet.
SuperCam, one of the seven instruments embarked on the rover, was built with the participation of a French team of several dozen engineers and scientists from CNES, CNRS and universities. It integrates into the volume of a cereal box, functionalities that normally require several major pieces of equipment. It emits a pulsed laser beam from an optical module housed in the rover’s mast to remotely pulverize very small quantities of rock, thus providing essential information for the success of the mission.
A long reach
Using the laser beam, scientists can explore the chemical and mineralogical diversity of the sites crossed by the rover. Evaluating these sites saves time and allows them to find the most interesting rock targets. Generally, these are rocks formed in the presence of water, such as clays, carbonates and sulphates. Water is essential for the formation of life, including microbes, which could have been found on Mars billions of years ago. Scientists can also use the information from SuperCam to decide whether it is useful to drill core samples from the ground for the rover’s sample collection system. Mars2020 will store them in metal tubes, and then deposit them in designated locations where a future sample return mission will retrieve them and return them to Earth.
Focusing the laser beam
SuperCam is a “new generation” version of the ChemCam instrument of the Curiosity rover, which landed on March 6, 2012. Like its predecessor, SuperCam will use an infrared laser beam, focused on the surface of the rock to a diameter of less than a millimeter, to heat the rock to about 10,000 degrees Celsius – the Laser Induced Breakdown Spectroscopy (LIBS) technique – to pulverize a small fraction of the rock. Spectrometers then determine the chemical composition of these rocks from the hot gas or plasma thus created. SuperCam will also be able to determine their mineralogical composition. To do this, it can use an infrared spectrometer or emit a green beam, which will make certain carbon-based chemicals fluoresce or glow. This technique is called “Raman spectroscopy”.
Laser with soundtrack
SuperCam incorporates a microphone that allows you to listen to each laser shot. The sound of the impact on the different rocky materials is indicative of their physical properties. Scientists at the SuperCam project are eager to test this new feature and see what kind of useful information it can provide. “The microphone, provided by ISAE-SUPAERO, allows us to learn about our rock targets from a distance, but the nice thing is that we can also use it to directly record the sound of the Martian landscape or the rotation of the rover’s mast. “This will, in fact, be the third time that this type of microphone will go to Mars,” says Sylvestre Maurice, professor-researcher at the Institut de recherche en astrophysique et planétologie (Irap -CNES/CNRS/Université Toulouse III -Paul Sabatier), in Toulouse. At the end of the 1990s, the same type was on board the Mars Polar Lander probe, which crashed on the planet’s surface. And in 2008, the Phoenix mission experienced electronic problems that prevented the use of his microphone.
A Franco-American instrument
SuperCam is a Franco-American instrument. The American contribution developed by Los Alamos National Laboratory (LANL) is located inside the rover (called “Body Unit”). This part of the instrument includes several spectrometers, control electronics and software. The Mast Unit has been developed by several CNRS laboratories and French universities under the responsibility of CNES. The third module, the calibration targets on the rover deck, is provided by the Spanish University of Valladolid. JPL is building the Mars2020 rover for NASA’s Science Mission Directorate and will manage its operations.
Strong French contribution
The CNES is the contracting authority for the French contribution to SuperCam. In its role as project owner, CNES provides Irap with experts in the field (components, planetary protection, electromagnetic, thermal and mechanical compatibility, optical integration and calculation, software programming) and technical means (components expertise laboratory, thermal chamber, shock test means). Concerning the instrumental contribution, CNES provides critical subsystems for the Mast Unit: laser, color imager, focusing mechanism, shutter mechanism (aiming to block the red laser beam when firing in green Raman), diodes for the autofocus function, etc. Concerning the ground mission and operations resources, CNES is responsible for the development of the French mission center (FOCSE Mars2020). This center is responsible for technical (CNES) and scientific (laboratories) operations, alternating with LANL.
Laboratories or institutes contributing to the construction or calibration of SuperCam:
- Irap:is in charge of the development, integration and testing of the SuperCam Mast Unit.
- Observatoire Midi-Pyrénées (CNRS/IRD/Météo-France/Université de Toulouse III -Paul Sabatier):in charge of the mechanical architecture.
- Laboratoire d’Astrophysique de Bordeaux (CNRS/Université de Bordeaux): responsible for the supply of the main electronic board and software of the Mast Unit.
- Laboratoire d’études spatiales et d’instrumentation en astrophysique (Observatoire de Paris-PSL/CNRS/Sorbonne Université/Université de Paris): provides the infra-red spectrometer.
- Laboratory “atmospheres and space observations”(CNRS/Sorbonne University/University of Versailles Saint-Quentin-en-Yvelines): provides the electronic map of the infra-red spectrometer.
- ISAE-SUPAERO(Institut supérieur de l’aéronautique et de l’espace):provides the microphone.
- Institut d’astrophysique spatiale (CNRS/Université Paris-Saclay): responsible for the calibration of the infrared channel.
- Sylvestre Maurice, firstname.lastname@example.org