Tumbleweed rovers are inflatable balls with mechanical control structures. Rolling across the Martian surface like a mechanical tumbleweed, such a rover could move faster and cover more ground than a wheeled rover like the Curiosity Mars Science Laboratory, at much lower cost. NASA and a number of universities have built and tested prototypes. NASA has tested prototypes in the Mojave Desert and the frozen waste of Antarctica.
A tumbleweed rover would use the Martian wind for locomotion and shifting balance for control. According to previous work at JPL, tumbleweed rovers could achieve speeds of 20 miles per hour in typical afternoon winds, compared to a top speed of 0.1 miles per hour for Curiosity. A tumbleweed rover 6 meters in diameter could climb over one-meter rocks and travel up 20-degree slopes in moderate winds and 45-degree slopes in strong winds. A 6-meter diameter rover would have a mass of 44 pounds and a 44-pound science payload. (The Curiosity rover weighs over 1,980 pounds.) Additionally, the rover’s inflatable ball can function as both parachute and airbag for the landing, saving on overall system weight.