NASA's Perseverance rover has driven farther on another world than any vehicle in history, reaching 45.22km, or 28.10 miles, on its odometer on Sol 2006, which fell on 11 October.
The category is the farthest distance driven on another celestial body. Guinness World Records recognised the achievement and presented a plaque to Perseverance's engineering twin on Earth.
The account was published by NASA in a post written by Vandi Verma, Chief Engineer for Robotic Operations at the Jet Propulsion Laboratory, who described the team drawing on "hard-won lessons" from 45 kilometres of driving.
The record nearly arrived two months earlier. On Sol 1947 the odometer sat about 200 metres short of the mark, a distance the rover's autonomous navigation system could have covered easily in a single drive.
It did not. The rover was working through a scientifically interesting area of ancient rock outcrops, making short drives to abrade rocks and carry out proximity science, and it passed the record only once the team was ready to move on.
Much of the distance is owed to two onboard systems. AutoNav drives the rover without waiting for instructions from Earth, and Global Localization, known as GBLC, works out where the rover has ended up by comparing what it can see on the ground with orbital imagery. Verma wrote that it places the rover "as though we had GPS on a world without it".
GBLC runs on a high-speed commercial processor salvaged from the Ingenuity helicopter's base station. Unlike the rover's main flight computer it is not radiation-hardened, so the team built a software approach to guard against what Verma called "transient bit flips" in its memory.
The driving rules themselves were rewritten after thousands of simulations. The tilt limit was raised to 24 degrees, the required clearance under the belly pan was cut to 20cm, braking software was updated to avoid rock hazards, and the steering motor current limits were nearly doubled.
Flight software also gained what the team calls dynamic slip tables, which model how much the wheels are expected to slide, and the drivers now use cross-slope routes to keep the wheels better anchored on exposed bedrock.
The team is exploring whether generative artificial intelligence can propose steering solutions across the legs of a planned route, which would hand still more of the driving to the rover itself.
The award is where this becomes interesting. The record is for distance driven on another celestial body, and the physical recognition of it is now held, on Earth, by a vehicle that has driven none.
The engineering twin is not a model or a mock-up. It is a complete, functioning rover, built alongside the one that flew, and it is used to rehearse manoeuvres before they are attempted on Mars. Its lifetime distance driven on another celestial body is nil, and it is not scheduled to change.
Records administration generally distinguishes between the holder of a record and the custodian of the certificate. In this case the distinction has been resolved in favour of the custodian, on the straightforward ground that the holder could not attend.
Our analysts accept that there was no alternative. The one object in the solar system qualified to receive the plaque is approximately a planet away and cannot be reached by courier, and the twin is the nearest thing to it that has an address.
So the position is settled. There is one vehicle in the universe that has driven 45.22 kilometres on another world, and one vehicle that has the paperwork. They are not the same vehicle, and only one of them can be visited.