NASA’s Mars rover, Curiosity, drives up a ramp during a test at NASA’s Jet Propulsion Laboratory, Pasadena, Calif., on September 10, 2010. The rover, like its smaller predecessors already on Mars, uses a rocker bogie suspension system to drive over uneven ground. Technicians and engineers in clean room garb watch the test drive carefully inside JPL’s Spacecraft Assembly Facility.
Curiosity “soft-landed” (wheels down) on the surface of Mars. But, even it’s called “soft-landing”, the touchdown speed was 0.6739m/s vertical and 0.044m/s horizontal, which could damage the wheels. Plus, while the rover is moving, the wheels should withstand the substantial damage through the rough Martian surface. That’s why the wheels of the Curiosity rover have been one of the biggest technical difficulties encountered on the mission.
The wheels on Curiosity are half a meter (20 inches) in diameter, twice the height of the wheels on earlier Mars rovers Spirit and Opportunity.
Curiosity has landed successfully on Aeolis Palus in Gale Crater on Mars on August 6, 2012, at 05:17 UTC.