How to drive a rover on Mars? This is a question that has certainly haunted the minds of some of us for ages. And as Perseverance prepares to land on the surface of the Red Planet, a NASA engineer has finally spoken on the subject …
If all goes well, Perseverance will land on Martian soil in less than two months. According to NASA forecasts, the rover should reach its target planet around mid-February. As the landing on Mars approaches, NASA engineer Evan Hilgemann recently provided some information relating to the techniques of piloting such a craft, reports Futurism.com . Hilgemann joined in 2019 the team of engineers responsible for driving the Curiosity rover through the desert landscapes of Mars.
He is therefore one of the few experts to have a certification to perform such an operation.
According to Hilgemann, driving a rover hundreds of millions of kilometers from a distance is far from child's play. The great difficulty stems in particular from the fact that the signals take more than 20 minutes to travel between Earth and Mars. Given this constraint, the rover was designed to be able to perform certain tasks on its own.
Perserverance is thus equipped with 3D cameras which allow it to see its near and far surroundings. Called "navcams", these devices are useful for the team on Earth to virtually recreate the environment in which the rover operates. As a result, journeys can be scripted and planned in advance. As a safety measure, the rover should avoid small rocks and loose terrain.
Several different ways to drive a rover
Still according to Hilgemann, there are several different techniques of driving a rover. In addition to instructions sent from Earth, the craft can be piloted using visual odometry. This piloting technique requires a stop of several minutes at approximately every meter, the time for the rover to send back an image of what it sees towards the control center and for the engineers to decide on the maneuvers to be carried out.
Finally, there is the “autonav” mode which, as the name suggests, transforms the rover into an autonomous vehicle. This mode, however, does not allow the machine to move quickly because it "must stop frequently to take several images and analyze data".