Perseverance rover sets a Martian speed record with software controls

NASA's Perseverance Mars rover has set a speed record by traversing a massive boulder field in a third the time it would have taken its predecessor Curiosity.

That isn't to say Perseverance is fast - to traverse Snowdrift Peak, a rocky region in the Jezero Crater the rover entered on June 26, it still took more than a month, with Perseverance emerging on the far side July 31 and ready to roll. 

"It was much denser than anything Perseverance has encountered before – just absolutely littered with these big rocks," said Tyler Del Sesto, deputy rover planner lead for Perseverance and NASA's Jet Propulsion Laboratory. "We didn't want to go around it because it would have taken us weeks. More time driving means less time for science, so we just dove right in."

Perseverance, which landed on Mars in 2021, is equipped with self-driving capabilities in the form of the AutoNav system, which is why NASA said the rookie rover is so much more capable than those that came before it. 

Even the earliest Mars rovers had some form of auto-navigation, but their capabilities were limited. The first Martian rover, Sojourner, had to take a break every 5.1 inches to reassess its plans. Spirit and Opportunity, which arrived on Mars in 2004, needed to pause every 1.6 feet to make the same determination. 

Curiosity, the rover currently exploring Mount Sharp, got an interplanetary patch last year to speed up its image processing and auto-navigation timing, but it still suffers from a need to take breaks to plan. Not so for Perseverance. 

"Perseverance is the first rover that has two computer brains working together, allowing it to make decisions on the fly," said Perseverance mission chief for robotic operations Vandi Verma. 

That ability to think on the fly allowed Perseverance to navigate Snowdrift Peak in a little over a month, but only a small portion of that was spent on the move - there were also days spent among the boulders doing science, too. 

"If you take out the sols (Martian days) dedicated to mission science, the traverse through Snowdrift Peak only took six autonomous drive sols, which is probably 12 sols faster than Curiosity would have taken," said Del Sesto.

By the time it exited the Peak, Perseverance had logged 2,490 feet (759 meters) of travel, compared to the original straight-line route planned by NASA that was just 1,706 feet (520 meters). Much of the distance between those two routes was due to AutoNav making decisions to maneuver around rocks that NASA said it was unable to see when making the route plan based on orbital images.

• Perseverance rover drops off first sample tube on surface of Mars
• Perseverance reveals more detail on Martian organic chemistry
• Perseverance rover shows up Curiosity with discovery of Martian water park
• Fresh details on the flash that sits inside Mars Perseverance Rover

Along with its masterful navigation of Snowdrift Peak, Perseverance has set other speed records since it arrived on Mars. Thanks to AutoNav, it holds the single-day drive distance record of a whopping 1,140.7 feet, or 347.7 meters - slightly less than a quarter mile. The longest Martian navigation without human assistance is also Perseverance's record at 2,296.2 feet, or 699.9 meters. 

Of course, those records were set on the flat bottom of Jezero Crater, NASA said, and the terrain Perseverance is facing in the coming days and months won't be anywhere nearly that forgiving. 

As the rover continues on its quest to search for signs of biological life on Mars - part of which may be in danger - Perseverance began crossing the Mandu Wall, a ridgeline along the inner edge of Jezero's western rim, earlier this month. 

"This new terrain is definitely going to throw a few curveballs at us and AutoNav," said Mark Maimone, Perseverance's deputy team chief for robotic operations. "But that is where the science is. We're ready." ®