Wind speeds on Mars are excessive sufficient to blow fleets of enormous spherical rovers that resemble tumbleweed throughout the Red Planet’s floor, based on new wind-tunnel checks of small prototypes carried out by a global consortium of younger scientists.
“We now have experimental validation that tumbleweed rovers could indeed operate and collect scientific data on Mars,” James Kingsnorth of the Delft University of Technology within the Netherlands and head of science at Team Tumbleweed mentioned in a statement.
The concept behind the Tumbleweed mission is to design large-scale, low-cost robotic rovers that can cover great swathes of the Martian surface while driven purely by the breeze.
Whereas the ultimate deliberate tumbleweed rovers can be 16 toes (5 meter) throughout, in April 2025, Team Tumbleweed examined a half-size prototype referred to as the Tumbleweed Science Testbed in a disused quarry within the Netherlands. The crew proved that even off-the-shelf devices might accumulate environmental information whereas the rover tumbled roughly throughout the terrain.
Then, in July 2025, Team Tumbleweed headed to Aarhus University’s Planetary Environment Facility in Denmark to check small 11.8-, 15.7- and 19.7-inch (30-, 40- and 50-centimeter) prototypes in a wind tunnel.
The prototypes have been spherical wire frames containing sails; within the wind tunnel, they have been put by their paces on totally different surfaces, together with tough and easy terrain, sand, pebbles and boulder fields. They have been then blown by totally different wind speeds and all underneath a low floor strain of 17 millibars to imitate circumstances on the Red Planet.
The checks confirmed that wind speeds as little as 30 to 33 toes per second (9 to 10 meters per second) have been enough to push the tumbleweed rovers, whereas onboard sensors have been profitable in capturing information because the rovers tumbled. The prototypes have been even capable of ascend slopes of 11.5 levels pushed solely by the wind. While this doesn’t sound terribly steep, this was in Earth‘s gravity — in the lower gravity of Mars, this would be equivalent to a 30 degree slope.
“Experiments with the prototypes in the Aarhus wind tunnel have provided big insights into how tumbleweed rovers would operate on Mars,” Mário João Carvalho de Pinto Balsemão, who is Team Tumbleweed’s mission scientist at Universidad de Lisboa (Lisbon) in Portugal, said in the statement. “The results are conservative, as the weights of the scaled prototypes used in the experiments are exaggerated compared to the real thing, so the threshold wind speeds for setting the rovers rolling could be even less.”
That’s good news for the potential success of real tumbleweed rovers on Mars. Although measurements of near-surface wind speeds on Mars are sketchy, NASA’s InSight lander was frequently shaken by winds stronger than 6.2 miles (10 kilometers) per second, while the Ingenuity helicopter also measured winds of similar strength.
“The results from Aarhus support our modeling, which shows that an average tumbleweed rover – following the daily shifts and day–night cycles of the wind — could travel about 422 kilometers [262 miles] over 100 Martian sols, with an average overall speed of about 0.36 kilometers [0.22 miles] per hour,” said Balsemão. “In favorable conditions, the maximum range could be as much as 2,800 kilometers.”
Swarms of tumbleweed rovers could transform our exploration of the Red Planet, capable of taking environmental data simultaneously from myriad locations to create wide maps of atmospheric and surface processes. At the end of their roving missions they can even collapse to form stationary platforms that can continue taking data for many years.
The team’s next step is to head to the Atacama Desert in Chile in November to test the prototypes with more sensitive instruments to see if they can collect precision data while the rovers tumble over the terrain. Although currently the tumbleweed rover has not been adopted as a mission by any space agencies, by developing the technology it puts the project in prime position in the future to be selected to go to Mars.
The latest tumbleweed update was presented by Kingsnorth at the joint Europlanet Science Congress–AAS Division of Planetary Science assembly in Helsinki in September.