Feb 17, 2022 - Science

NASA’s Perseverance rover prepares for its longest Mars drive yet

Perseverance's tracks on Mars
Perseverance's tracks on Mars. Photo: NASA/JPL

After a year on Mars, NASA's Perseverance rover is preparing to set off on its longest trip yet on the surface of the Red Planet, driving stretches of the journey all by itself.

The big picture: The mission to Mars, designed to search for evidence of ancient life on the planet and collect samples that could be brought back to Earth for the first time by a future mission, hints at how robots will help humans explore the solar system in the future.

Catch up quick: Perseverance landed in Mars' Jezero Crater — once a lake fed by rivers — on Feb. 18, 2021. The site, later named to honor science fiction writer Octavia E. Butler, is about 1.5 miles from where the rover was supposed to land near a dry river delta that is the central focus of the mission.

  • For the past year, Perseverance explored its neighborhood, making surprising discoveries on the crater floor by happenstance.
  • It spotted big boulders high up on the delta that scientists think were deposited there by large floods, suggesting the crater had filled up with water in multiple stages.
  • The rover also sent data that to scientists' surprise indicate some of the rocks on the Jezero crater floor are igneous — those formed from lava. These types of rocks can be dated with accuracy and precision, so if returned to Earth in the future, they could give scientists "the first quantitative pin on the x-axis of Mars' history," says Kenneth Farley a geochemist at Caltech and project scientist for the mission.

What's next: Perseverance is about to head back to its landing site and on to the delta — its original destination where scientists think lake bottom muds formed sedimentary rocks that can hold their own secrets, including signs of past life.

  • In the cliffs of the delta, the rover will search for ancient beach deposits that may have trapped minerals and maybe even microbes, says Briony Horgan, a planetary geologist at Purdue University and member of the Perseverance science team.

How it works: The roughly 3.7 mile trip to the delta — more than twice the total miles traveled by Perseverance in the past year — is expected to take about three months, Farley says. That's about half the time it would have taken with earlier rovers.

  • A key advance from NASA's Curiosity rover that landed on Mars in 2012 is that Perseverance can navigate autonomously with a little help from human commanders on Earth who use satellite imagery to tell the rover to avoid large areas of deep sand and other major hazards.
  • The rover collects images of its environment, processes them and moves all at the same time rather than in sequence with guidance from operators. Perseverance then can drive autonomously four to five times faster than Curiosity, says Michael McHenry of NASA's Jet Propulsion Laboratory who helped design Perseverance's navigational system called AutoNav.
  • Earlier this month, the rover set a record by traveling more than 800 feet in one Martian day. "It was exciting and a long time coming," McHenry says.

The rover's speed is key to its mission: collect as many types of rock samples from as many different places on the Martian surface as possible

  • So far, it's collected three unique samples, with a fourth near the landing site planned in another week or two, says Horgan. (Each sample is a pair.)

The big picture: Robots have supported space exploration for decades but recent advances in autonomous driving and drones are opening new types of planetary exploration.

  • Ingenuity, the helicopter that accompanies Perseverance, is paving the way. A large drone, Dragonfly, is slated to fly over Saturn's moon Titan in search of signs of life and its origins.
  • A new helicopter mission to Mars that would go thousands of miles across the planet visiting multiple sites to gather data could help to piece together the 4 billion year history of the planet, Horgan says.

Perseverance's autonomous ability "foreshadows the creation for later Mars expeditions of truly autonomous robots that will study the landscape and choose the best routes on their own," science writer Donald Goldsmith and astronomer Martin Rees write in their forthcoming book, "The End of Astronauts: Why Robots Are the Future of Exploration."

  • They say the advantages that human explorers now hold over robots — including moving more quickly and exercising judgment — will diminish as AI and robotics advance.
  • If — and it is a big, far off if — robots can match human scientists, Goldsmith and Rees argue it would reduce the need — but not necessarily the desire — to put humans on the Red Planet.

Editor's note: This story has been clarified to explain that each sample collected by the rover is a pair.

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