On a recent day in November, the car-size rover rolled slowly forward, then stopped, perched on the threshold of a Martian landscape. But this rover, named OPTIMISM, wasn’t on the Red Planet. And the landscape was a boulder-strewn mock-up of the real Mars—the Mars Yard at NASA’s Jet Propulsion Laboratory in Southern California.
Click here for original story, Twin of NASA’s Perseverance Mars rover begins terrain tests
Source: Phys.org