Rover Perseverance gets its own navigation system

Five years after landing, the US space agency National Aeronautics and Space Administration (NASA) has installed a navigation system on the Perseverance rover. This allows it to determine its position on Mars autonomously. Previously, the Mars robot received this information from Earth.

Mars Global Localization is what NASA calls the system that determines location on an optical basis. The system was first used on February 2nd, NASA announced, and again on February 16th.

The basis for this is the panoramas captured by the navigation camera of the rover's surroundings. The algorithm compares these images with a terrain map. This map was created from images taken by the Mars Reconnaissance Orbiter (MRO) probe, which orbits Mars, and is stored on Perseverance's onboard computer.

Positioning accuracy up to 25 centimeters

This allows the rover's position to be determined with an accuracy of about 25 centimeters. This takes about two minutes. The algorithm runs on the powerful processor that the rover previously used to communicate with the Mars helicopter Ingenuity.

Until now, Perseverance – like its predecessors – has used visual odometry (VO) for positioning. With VO, an image of the surroundings is taken every few meters. Based on geological features in the images, the distance the rover has traveled is calculated.

However, even if factors like wheel slippage are considered, positioning becomes increasingly inaccurate on longer journeys, according to NASA. On long drives, the deviation can be up to 35 meters. In difficult terrain, this can put the rover in danger.

Help with autonomous driving

The Mars Global Localization System is particularly helpful when the rover operates autonomously and without guidance from Earth. “Now it can determine its location on Mars,” said Vandi Verma, who is responsible for the rover's autonomous operations. “This means the rover can cover much longer distances autonomously, allowing us to explore more of the planet and gain more scientific insights. It could be used by almost any other rover to travel quickly and far.”

Perseverance, which is largely identical in design to the Curiosity rover, has been operating on Mars for five years, since February 18, 2021. Since then, it has traveled about 40 kilometers and will soon set the record of the Opportunity rover, which covered about 45 kilometers in its nearly 15-year mission.

(wpl)