NASA's Curiosity Rover has notched up 4,000 days on Mars as the trundlebot continues its fourth extended mission despite showing signs of wear and tear.

The nuclear-powered rover touched down in Gale Crater in 2012 and has since been studying the Red Planet to determine if ancient Mars could have supported microbial life. It has drilled 39 samples over the years and is currently making its way up the base of the 3-mile-tall Mount Sharp to allow geologists to take a closer look at rock layers showing how Mars' climate has changed.

It's not always been plain sailing for the rover. Across the decade-and-a-bit Curiosity has spent trundling over the surface of the planet, it has covered almost 20 miles (32km) through what NASA describes as "a punishingly cold environment bathed in dust and radiation," yet the Agency says "Curiosity remains strong."

The conditions have, however, taken their toll. One of the rover's "eyes" - the 34mm focal left camera of the Mast Camera - has a filter wheel stuck between filter positions. Wear and tear was also noticed on the rover's drill system and arm joints, and, of course, the wheels have famously incurred some impressive damage while rolling over Mars.

For the wheels, engineers admitted that they misjudged the conditions encountered on the Martian surface. For the eyes, the plan is to gently encourage the filter wheel back to its standard position. If that fails, then there's always the 100mm right camera, but according to the team, nine times the number of images would be needed for the same area.

Many issues have been resolved or at least mitigated through software updates - the addition of a traction control algorithm, for example, helped decrease wear and tear on wheels from sharp rocks.

Curiosity has now far outlived its initial two-year mission but has a while to go before achieving the impressive longevity of its predecessor - Opportunity, which depended on solar panels. Curiosity is powered by a radioisotope thermoelectric generator (RTG) and, according to NASA, mission engineers expect the nuclear power source to keep the rover running for "many more years."

Communications are set to pause in November due to Mars disappearing behind the Sun from the perspective of Earth, a phenomenon known as solar conjunction. Engineers expect to resume contact with Curiosity after November 28. ®

https://www.theregister.com//2023/11/07/4000_days_of_curiosity/