Perseverance rover achieves 90% autonomous navigation on Mars with new self-driving systems

Mars Rover Sets Self-Driving Record

In past missions to Mars, like with the Curiosity and Opportunity rovers, the robots mostly relied on human instructions from millions of miles away in order to safely navigate the Martian landscape. The Perseverance rover, on the other hand, has zipped across the alien, boulder-ridden land almost completely autonomously, smashing previous records for autonomous driving on Mars. Whereas the Curiosity rover completed about 6.2 percent of its travels autonomously, Perseverance had completed about 90 percent of its travels autonomously, as of its 1,312th Martian day since landing (28 October 2024). Perseverance was able to accomplish such a feat -- using remarkably little computing power -- thanks to its specially designed autonomous driving algorithm, Enhanced Autonomous Navigation, or ENav. The full details on ENav's inner workings and how well it has performed on Mars are described in a study published in IEEE Transactions on Field Robotics. There are some advantages, but some serious challenges when it comes to autonomous navigation on Mars. On the plus side, almost nothing on the planet moves. Rocks and gravel slopes -- while formidable obstacles -- remain stationary, offering rovers consistency and predictability in their calculations and path-finding. On the other hand, Mars is in large part unchartered terrain. "This enormous uncertainty is the major challenge," says Masahiro (Hiro) Ono, supervisor of the Robotic Surface Mobility Group at NASA's Jet Propulsion Laboratory, who helped develop ENav. While some images from the space-borne Mars Reconnaissance Orbiter exist, these are usually not high enough resolution for ground-based navigation by a rover. In December, NASA engineers performed the first test of a navigation technique that uses a model based on Anthropic's AI to analyze MRO images and generate waypoints -- the coordinates used to guide the rover's path -- for more complete automation. But in the majority of today's navigation, Perseverance must rely on images the rover itself takes, analyze these to assess thousands of different paths, and choose the right route that won't end in its own demise. The kicker? It must do so with the equivalent computing capacity of a iMac G3, an Apple computer sold in the late 1990s. This is because older CPUs can undergo radiation hardening, a process that makes them resilient to the extreme levels of solar radiation and cosmic rays experienced on Mars. Newer CPUs with more computing power, on the other hand, cannot work under such extreme conditions. Therefore, researchers must work with what they have -- a computer core from the 1990s. Given its limited computing resources, the ENav algorithm was strategically designed to do the heaviest computing only when driving on challenging terrains. It works by analyzing images of its surroundings and assessing about 1,700 possible paths forward, typically within 6 meters from the rover's current position. Assessing factors such as travel time and terrain roughness, it ranks possible paths. Finally, it runs a computationally heavy collision checking algorithm, called ACE (approximate clearance estimation) on only on a handful of top-ranked potential paths. Perseverance landed on Mars on 18 February 2021. In their study, Ono and his colleagues describe how the rover was initially deployed with strong human navigation oversight during its first 64 Martian days on the Red Planet, but then went on to predominantly use ENav to travel to one of the major exploration targets: the delta formed by an ancient river that once flowed into Jezero Crater billions of years ago. Scientists believe it could be a prime spot for finding evidence of past alien life, if life ever existed on Mars. After a brief exploration of an area southwest of its landing site, Perseverance jetted counterclockwise around sand dunes towards the ancient river delta at a crisp pace, averaging 201 meters per Martian day. (It's too cold for the rover to travel at night.) Over the course of just 24 Martian days of driving, the rover traveled about 5 kilometers into the foothill of the delta. 95 percent of all driving that month was performed using the autonomous driving mode, resulting in an unprecedented amount of autonomous driving on Mars. Past rovers, such as Curiosity, had to stop and "think" about their paths before moving forward. "That was the main speed bump for Curiosity, why it was so slow to drive autonomously," Ono explains. In contrast, Perseverance is able to think and drive at the same time. "Sometimes [Perseverance] has to stop and think, particularly when it cannot figure out a safe path quickly. But most of the time, particularly on easy terrains, it can keep driving without stopping," Ono says. "That made its autonomous driving an order of magnitude faster." Opportunity held the previous record for autonomous driving on Mars, traveling 109 m in a single Martian day. But on 3 April 2023, Perseverance set a new record by driving 331.74 m autonomously (and 347.69 m in total) in a single Martian day. Ono says that fine-tuning the ENav algorithm took a lot of work, but he is happy with its performance. He also emphasizes that efforts to continue advancing autonomous navigation are critical if humans want to continue exploring even deeper into space, where Earthly communication with rovers and other spacecraft will become increasingly difficult. "The automation of the space systems is unstoppable direction that we have to go if we want to explore deeper in space," Ono says. "This is the direction that we must go to push the boundaries and frontiers of space exploration."

NASA's Perseverance rover learned to find its own way around Mars

Mars is a lonely place to drive. For five years, NASA's Perseverance rover has been roaming its cold, dusty surface with no roads and no GPS. Every move it makes matters. One wrong turn could send it toward sharp rocks or soft sand. Until recently, the rover had to pause and ask Earth for help to know exactly where it stood. Engineers would study images, compare them with maps taken from orbit, and then send back new instructions. Perseverance could handle many tasks on its own, but it still needed people to confirm its precise location. Now, that has changed. A new system called Mars Global Localization lets Perseverance figure out where it is without waiting for a reply from Earth. The rover can finally check its own position on Mars and keep going. Mars Global Localization works in a pretty straightforward way. The rover looks around, snaps wide panoramic photos, and compares what it sees to detailed maps taken from orbit. It's basically checking its surroundings against images captured by NASA's Mars Reconnaissance Orbiter to figure out exactly where it's sitting. The software runs on a powerful processor that once helped Perseverance communicate with the Ingenuity helicopter. In about two minutes, the rover can narrow down its position to within about 10 inches. The team first used the system during regular mission operations on February 2, and then again on February 16. "This is kind of like giving the rover GPS. Now it can determine its own location on Mars," said JPL's Vandi Verma, chief engineer of robotics operations for the mission. "It means the rover will be able to drive for much longer distances autonomously, so we'll explore more of the planet and get more science. And it could be used by almost any other rover traveling fast and far." The technology was developed at NASA's Jet Propulsion Laboratory in Southern California. It builds on decades of robotics research, much of it focused on how machines can safely move through unknown terrain without constant human input. On Earth, your phone connects to a network of satellites to find your position. Mars has no such network so the rover must rely on a method called visual odometry. Perseverance studies features in the landscape and tracks how they shift as it moves, while also accounting for wheel slippage. Over short distances, that works well. Over longer drives, tiny errors pile up. On some trips, the rover's estimated position could drift by more than 100 feet. If it thought it might be too close to danger, it would stop and wait. "Humans have to tell it, 'You're not lost, you're safe. Keep going,'" Verma said. "We knew if we addressed this problem, the rover could travel much farther every day." With Mars Global Localization, Perseverance can stop, compare its surroundings with orbital maps, correct its position, and continue along its planned route. That means fewer delays and more ground covered. This update comes soon after another change. The Perseverance team began using generative artificial intelligence to help plan drive routes. The system selects waypoints that human operators once chose by hand. Together, these tools let the rover travel farther and faster on Mars while reducing the team's workload. That matters because every minute of rover time is precious. Perseverance is exploring Jezero Crater, a site believed to have once held a lake. The rover is searching for signs of ancient microbial life and collecting rock samples for a future mission that aims to bring them back to Earth. The better the rover can navigate on its own, the more science it can accomplish. The key to this advance sits inside a box called the Helicopter Base Station. Perseverance used it to communicate with the Ingenuity helicopter, which completed 72 flights even though it was expected to fly no more than five. The base station carries a commercial processor similar to those found in many mid-2010s smartphones. It runs more than 100 times faster than the rover's two main computers. Those main computers are built to survive Mars' harsh radiation and are based on hardware introduced in 1997. Using commercial chips in space is risky because radiation can damage memory. During testing, engineers found that about 25 bits out of the processor's one gigabyte of memory were damaged. That is a tiny fraction, but it matters. The team created a system to isolate those bits and added a confidence check that runs the algorithm multiple times before the rover's main computer confirms the result. "We've given the rover a new ability," said Jeremy Nash, a JPL robotics engineer who led the team working on the project under Verma. "This has been an open problem in robotics research for decades, and it's been super exciting to deploy this solution in space for the first time." Before using the system on Mars, the team tested it with data from 264 previous rover stops. Each time, the algorithm correctly identified the rover's location. The impact of this technology goes beyond one rover. Future missions to Mars could use similar systems to travel longer distances with less back-and-forth communication. Crewed missions would also need reliable ways to track vehicles and equipment across wide, dusty landscapes. Engineers are already thinking about the Moon. Lunar missions face their own navigation challenges, including long, dark nights and tricky lighting conditions. Knowing exactly where a spacecraft sits could mean the difference between success and failure. For now, Perseverance keeps rolling. It no longer has to wait for someone millions of miles away to tell it where it stands. It can check for itself and move forward, one careful drive at a time. -- - Like what you read? 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