Wind speeds on Mars are excessive sufficient to blow fleets of enormous spherical rovers that resemble tumbleweed throughout the Purple Planet’s floor, in accordance with new wind-tunnel assessments of small prototypes performed by a world consortium of younger scientists.
“We now have experimental validation that tumbleweed rovers may certainly function and acquire scientific knowledge on Mars,” James Kingsnorth of the Delft College of Expertise within the Netherlands and head of science at Staff Tumbleweed stated in a assertion.
The concept behind the Tumbleweed venture is to design large-scale, low-cost robotic rovers that may cowl nice swathes of the Martian floor whereas pushed purely by the breeze.
Whereas the ultimate deliberate tumbleweed rovers can be 16 toes (5 meter) throughout, in April 2025, Staff Tumbleweed examined a half-size prototype known as the Tumbleweed Science Testbed in a disused quarry within the Netherlands. The staff proved that even off-the-shelf devices may acquire environmental knowledge whereas the rover tumbled roughly throughout the terrain.
Then, in July 2025, Staff Tumbleweed headed to Aarhus College’s Planetary Surroundings 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 had been spherical wire frames containing sails; within the wind tunnel, they had been put by means of their paces on completely different surfaces, together with tough and easy terrain, sand, pebbles and boulder fields. They had been then blown by completely different wind speeds and all beneath a low floor stress of 17 millibars to imitate circumstances on the Purple Planet.
The assessments confirmed that wind speeds as little as 30 to 33 toes per second (9 to 10 meters per second) had been ample to push the tumbleweed rovers, whereas onboard sensors had been profitable in capturing knowledge because the rovers tumbled. The prototypes had been even in a position to ascend slopes of 11.5 levels pushed solely by the wind. Whereas this doesn’t sound terribly steep, this was in Earth‘s gravity — within the decrease gravity of Mars, this could be equal to a 30 diploma slope.
“Experiments with the prototypes within the Aarhus wind tunnel have supplied massive insights into how tumbleweed rovers would function on Mars,” Mário João Carvalho de Pinto Balsemão, who’s Staff Tumbleweed’s mission scientist at Universidad de Lisboa (Lisbon) in Portugal, stated within the assertion. “The outcomes are conservative, because the weights of the scaled prototypes used within the experiments are exaggerated in comparison with the actual factor, so the edge wind speeds for setting the rovers rolling may very well be even much less.”
That is excellent news for the potential success of actual tumbleweed rovers on Mars. Though measurements of near-surface wind speeds on Mars are sketchy, NASA’s InSight lander was continuously shaken by winds stronger than 6.2 miles (10 kilometers) per second, whereas the Ingenuity helicopter additionally measured winds of comparable power.
“The outcomes from Aarhus help our modeling, which reveals that a median tumbleweed rover – following the each day shifts and day–evening cycles of the wind — may journey about 422 kilometers [262 miles] over 100 Martian sols, with a median general velocity of about 0.36 kilometers [0.22 miles] per hour,” stated Balsemão. “In favorable circumstances, the utmost vary may very well be as a lot as 2,800 kilometers.”
Swarms of tumbleweed rovers may remodel our exploration of the Purple Planet, able to taking environmental knowledge concurrently from myriad areas to create huge maps of atmospheric and floor processes. On the finish of their roving missions they’ll even collapse to type stationary platforms that may proceed taking knowledge for a few years.
The staff’s subsequent step is to move to the Atacama Desert in Chile in November to check the prototypes with extra delicate devices to see if they’ll acquire precision knowledge whereas the rovers tumble over the terrain. Though at present the tumbleweed rover has not been adopted as a mission by any area companies, by creating the expertise it places the venture in prime place sooner or later to be chosen to go to Mars.
The newest tumbleweed replace was offered by Kingsnorth on the joint Europlanet Science Congress–AAS Division of Planetary Science assembly in Helsinki in September.
