Perseverance: extreme testing for SuperCam components
On 18 February, after a journey of almost seven months and 480 million kilometres, the Perseverance rover landed safely on Mars.
Everyone following the touchdown shared the excitement of the teams coordinating and watching the operation from mission control. You could almost hear the gasp of relief and sheer joy of the project engineers and scientists as the rover made its kiss landing.
The landing phase was not without its risks — NASA even described it as "seven minutes of terror" — but it turned out to be a huge success for the American agency and marked the beginning of a new age of scientific discovery.
And Thales is part of the adventure. In partnership with CNES, the French space agency, our teams helped qualify SuperCam's components for operation in space. The geological observatory on board the Perseverance rover comprises two instruments — a camera and a laser. Both of them are key to the success of the Mars 2020 mission to search for potential biosignatures, or signs of past life, on the Red Planet.
COTS components for state-of-the-art instruments
To limit its movements on Mars, which cost a lot of time and energy, Perseverance will take pictures of its environment using a suite of 16 cameras, including SuperCam. Panoramic images and close-ups will help scientists and other experts at the FOCSE* centre at CNES's Toulouse facility and the other control centres to determine the most suitable areas for taking samples.
That's where SuperCam's latest-generation Thales laser comes into play. Like its predecessor on ChemCam, which is still in service on Curiosity, SuperCam's laser interacts with matter every time it fires to form a spark with an instantaneous temperature of up to 10,000°C. This spark emits a brief pulse of light. The ultraviolet component of this light is analysed by the instrument's UV spectrometers, built by the Los Alamos National Laboratory in New Mexico. The spectrum obtained is then used to determine the elementary composition of the sample.
What's new with the SuperCam is that its laser can also emit a second green beam, which is used to determine the molecular composition of surface materials. This analysis technique, called Raman spectroscopy, can identify the potential biochemical signatures of lifeforms, and is being used on Mars for the very first time.
* FOCSE: French Operations Centre for Science and Exploration
Cutting-edge tools designed to cost
To limit costs, the instruments were built using standard, commercially available components selected after rigorous testing by Thales engineers.
We had the privilege and the responsibility of literally holding parts of the flight models of two SuperCam instruments in our hands, enthused Hélène Chauvin, technology expert at Thales's Security and Reliability Evaluation Department, CyberDefence Solutions.
Shakedown under the microscope
During the seven-month voyage and now on the Red Planet, SuperCam's instruments need to withstand some of the toughest conditions imaginable. So before they were sent into space, they were put through their paces by the Thales teams to test their reliability.
Extreme operating conditions accelerate the ageing of components. To be selected, they needed to show they could withstand extreme conditions, including temperatures ranging from –170 to +60°C, exposure to radiation, shocks and vibrations, electrical surges and more. During the tests, Thales engineers systematically analysed each component to evaluate their reliability and service life.
They also subjected two SuperCam components to an advanced technological analysis to detect the slightest manufacturing defect. They put each component through demanding mechanical and environmental tests, looked for any potential flaws under a microscope, and then carefully compared their results with the latest space industry standards.
Pride and passion in Toulouse
"To conduct this kind of test, you need a highly competent team and some pretty sophisticated equipment," says Aurélien Janvresse, project manager for the Security and Reliability Evaluation team, which is part of Thales CyberDefence Solutions.
Based at CNES's field centre in Toulouse, the team tests the reliability of electronic system components for customers in a wide range of sectors, from energy to automotive and defence, as well as space.
The team has access to CNES's state-of-the-art equipment: a chemistry and sample preparation laboratory, X-ray tomography equipment, high-resolution scanning electron microscopes, focused ion beam (FIB) systems, test and diagnostic equipment and optical benches.
We're extremely proud to have contributed to Perseverance's success, said Aurélien Janvresse. It's really exciting to think that the components we've held in our hands are now on Mars!
It's not exactly the first time the team has experienced the thrill of space exploration. The Curiosity rover has been on Mars since 2012, and its components were tested by our ITSEF information technology security evaluation facility, as were parts of the Rosetta probe, which landed on comet 67P (aka Churyumov-Gerasimenko, or Cherry-Gerry) in 2014.
Upcoming destinations for components tested by the Thales teams include the Moon and Phobos, one of Mars's two natural satellites. The voyage continues!
> The exploration of Mars: taking the next steps
> ITSEF | Security and Reliability Evaluation