AutoNav guided over 90% of the miles that put Perseverance past Opportunity's record

The drive that crossed the line was short. It covered 299.6 feet ^[10], about 22% of the 1,351 feet Perseverance can manage in a Martian day ^[11][20]. The 28.10-mile total sits 0.04 mile above Opportunity's mark ^[15], a margin thin enough that pace is the better evidence. Divide each rover's distance by its years and Perseverance averages roughly 5.1 miles a year ^[16] against Opportunity's roughly 1.9 ^[17]. That is about 2.7 times the yearly rate ^[18].

NASA's explanation is AutoNav. According to the coverage of NASA's statement, much of Perseverance's progress comes from the system ^[5], and it has guided more than 90% of the total distance ^[4]. On 28.10 miles, that is more than 25 miles under AutoNav ^[19]. The comparison figure, about 5%, belongs to Opportunity's early autonomous navigation system ^[4]. The two numbers describe different generations of software, so they show how far the technology has moved. The reported account says "much of" and does not say how much of the 2.7-times pace gap belongs to AutoNav.

In what NASA calls "thinking while driving" ^[7], onboard cameras capture images and the system builds a three-dimensional map of hazards ^[6]. It then selects a safe route between waypoints, and engineers on Earth choose those waypoints ^[6].

Steven Lee, project manager for the Curiosity and Perseverance rovers at NASA's Jet Propulsion Laboratory, put the longer view this way: "The original mission called for no more than 12.4 miles of driving. We've blown well past that, and with all mobility systems fully operational and favorable extended-ground-life test results, we expect Perseverance to keep adding to this record for many years to come," ^[8]. NASA is also changing the navigation software to reduce unnecessary steering and to help the rover determine its position from orbital maps while driving ^[13].

For a team deciding how to measure its own automation, the rover supplies a two-by-two. One axis is who sets the destination, a person or the machine. The other is what share of the distance the machine covers once the destination is set. Perseverance sits where people set destinations and the machine covers more than 90% of the way ^[4][6]. In that cell, a share-of-distance figure says something real about the software. A product where the machine also picks the destination needs a separate test of whether its picks were good.

We'd report the share-of-work number with the owner of the destination attached, and hold any claim about speed until a comparison isolates the software. The tradeoff is a less quotable headline, because a line saying the software covered most of the distance makes no claim about speed.