Perseverance on Mars: a year of chills and a lot of impatience

On February 18, 2021, NASA's rover approached the red planet after a seven-month journey.

The whole world held its breath to follow its vertiginous descent through the thin Martian atmosphere.

Seven long minutes of "terror", concluded by an immense relief when the vehicle deployed its wheels without incident on the site of an ancient lake, the Jezero crater.

This was followed by three months of breaking in the seven on-board instruments, on a rather hostile terra incognita.

"The Martian soil is a land of all dangers, full of pebbles, large dunes ...", described to AFP Pernelle Bernardi, CNRS engineer in charge of the Franco-American instrument SuperCam, "the eye " from Perseverance.

From its earliest days, it managed to record sounds and transmit them to Earthlings.

"It was one of the great discoveries of the year. No one had ever heard of Mars!", recalls Sylvestre Maurice, co-supervisor of SuperCam and astrophysicist at Irap at the University of Toulouse (CNRS/CNES ).

NASA Ingenuity helicopter on Mars, photographed by the Perseverance rover on June 15, 2021 Handout NASA/AFP/Archives

He is a regular on the red planet, where he has also co-piloted the Curiosity robot for nine years with the Americans, thousands of kilometers away, in the Gale crater.

"A new world"

But the planetologist is not ready to get tired of it: "We are drug addicts, we discover a new world, a bit like the explorers of the 15th century".

Every day, he goes through with his team the last deliveries of the robot.

“In twelve months, we collected a harvest of data on mineralogy, atmosphere, weather, and tens of thousands of images,” he lists.

A symbolic milestone, the date of the first anniversary coincides with that of the millionth laser shot on Mars, technology intended to read the chemical composition of rocks: 885,000 by Curiosity and 125,000 by Perseverance.

The hardest?

Undoubtedly the piloting of the vehicle, shared alternately and jointly every other week between the Cnes (the French space agency) in Toulouse and the Los Alamos National Laboratory (LANL) in the United States.

Every day, between 100 and 200 people find themselves at the helm.

"A team will want to roll, the battery team will say + wait, we're too weak, we have to recharge +, the arm team will want to add time to unfold it...", says the scientist.

"There are frustrations, but it's most often consensual... Americans have a real culture of compromise," says Nicolas Mangold, CNRS researcher in charge of SuperCam.

According to him, the hardest part of the past year will have been not being able to meet physically, due to the pandemic.

For now, Perseverance has traveled four kilometers - including 500 meters last weekend, a record.

There is no point in going fast: the objective of the mission is to collect around forty well-chosen samples over six years.

For another mission to bring them back to Earth, by the 2030s.

Perseverance using its Navcam navigation camera, August 20, 2021 Handout NASA/AFP/Archives

“You have to be patient, Perseverance is like a turtle, very intelligent,” comments Jim Bell, professor of astronomy at the University of Arizona, principal investigator of the Mastcam-Z instrument.

Heading for the delta

The rover has already collected seven samples - one of which failed (it was empty).

"It's a slow learning curve, but given all the constraints, I'm the happiest of scientists," says the American astrophysicist.

He remembers the historic flight of the Ingenuity helicopter, the rover's pathfinder.

And especially when, last fall, Perseverance proved that the landing site had been well chosen.

“We only had images in orbit suggesting a lake site. But when we saw, on ground images, that we were indeed on an old lake, fed by a delta river, like the Mississippi or the Mekong ... It completely turned us around."

After its first steps at the bottom of the crater, Perseverance will now set sail for the delta.

It is only two kilometers away, but he will have to go around a dune to reach it, by spring.

“We are so impatient!”, stamped Jim Bell.

Because it is this formerly fertile environment, where the mineral elements have accumulated, which is the most favorable to the development of a life form of the microbial type.

"Deposits from rivers are the most likely to have recorded the trace" of these primitive organisms, if they ever existed, concludes Nicolas Mangold.

© 2022 AFP