NASA's Perseverance Mars rover is days away from breaking the autonomous driving record, having traveled some 28 miles almost entirely autonomously, Ars Technica reports. With onboard navigation systems, it has traveled 90% of its Martian journey without human input, covering up to 150 meters an hour. Curiosity, by comparison, has spent about 10% of its time driving autonomously, traversing about 24 miles in over 15 years. Perseverance has traveled 28 miles in five years. This autonomy has helped the rover reach points of interest in the Jezero crater spaced further apart than those in Gale Crater, and it has arrived at new scientific locations ahead of schedule. The newer rover also has refined wheels, tougher than Curiosity's, which show considerable wear. However, the actuators within Perseverance's wheels were originally designed for up to 12 miles of driving distance, though they are being certified for up to 62 miles. The rover's radioisotope thermoelectric generator (RTG) has a half-life just shy of 90 years, though its operating lifespan is considered to be 14 years due to potential breakdown of supporting systems. Curiosity is fitted with the same system and is still operating after 15 years.