Perseverance has the most sophisticated autonomous driving system ever sent to Mars, which has allowed it to traverse hundreds of meters per drive. So why is it struggling now to go even a fraction of that distance on this episode of Mars Guy? Autonomous vehicles are becoming ever more common on Earth. Every day I see fully autonomous taxis safely navigating the streets of my city and little rovers traversing the sidewalks on the campus where I work. I marvel at this technology and think about it in the context of Mars rovers, wishing they could cover ground as quickly. But obviously streets and sidewalks couldn't be more different than the boulder and sand strewn ground that rovers cover. That's become ever clearer in recent weeks for the Perseverance Rover. It had routinely been covering 200 plus meters per drive in the terrain known as the margin unit. It's still in the same terrain, but since departing the unusual rock where it got its most recent sample, Perseverance hasn't even managed a hundred meter drive and most are much less. One of its drives was downright dismal covering maybe just over a meter too short to even show up on the map. Here's the view from the front Hascam with Mars Guy for scale in the spot where the short drive ended. So this is the view from the starting point and here's the view from the ending point. There's nothing obvious that represents a drive impediment. It didn't actually hit this little rock which it should have easily been able to drive over. The view out back offers other clues. Here's the ending point of the previous drive. You can see sand that's piled up along the track and the lack of clear imprints of the wheel cleats. There's also sand inside the wheel. These are all signs that the wheel was spinning in the sand, maybe enough to trigger some prescribed wheel spin threshold that brought an end to that drive. Three solves later, the next drive attempt appeared to proceed without wheel spin, but then it started about a meter in where the drive ended. It's hard to believe that such a minor amount of wheel spin would shut down the drive, so there's probably something else going on. The following drive managed to go a modest 56 meters, but it shows signs of perseverance struggling along the way. At this location it diverted nearly 90 degrees to the south, apparently stopping to document why. Here's the view out the windshield that shows sandrifts that perseverance are probably identified as a hazard. The view to the north has a lot of big boulders it probably considered too dicey to go over. The view to the south looks more benign, so perseverance chose to go this route. Here's the view from its final spot looking back at the location that forced the detour. The sandrifts look pretty small, mixed with rocks that aren't obvious hazards, so it seems like perseverance overreacted. The view out front looks as though perseverance was second guessing itself. It drove maybe half way over a sand drift before stopping and doing a complete 360, then backing away as if it was scared by something it saw. Of course, perseverance has a computer brain that's incapable of fear, but something's going on in there that's got it spooked by this landscape.