The Jet Propulsion Laboratory sandbox (Mars Yard) is a terrain of decomposed granite, brick dust and basalt rocks that has helped test various robotic vehicles (rovers) over the years.
The Jet Propulsion Laboratory in Pasadena, Calif. has its own playground. You won't find swings, slides, nor children cavorting about. This is a serious sandbox with basalt rocks transported from the Mojave Desert and strewn about to mimic the surface of Mars. JPL's sandbox is in its third iteration
The latest player in the sandbox was the rover Curiosity, weighing in at 1,980 pounds (including 180 pounds of equipment), with dimensions of 9.5 ft. long, 8.9 ft. wide and 7.2 feet tall. Curiosity, of course, left the terrestrial sandbox some time ago for the more exotic sands of Mars. It made sensational worldwide news when it set down on Mars on Aug. 6 after a 354 million mile journey. Curiosity approached Mars at 13,000 mph, well within the Martin speed limit, but slowed to 900 mph when it hit the atmosphere (the school zone speed limit), then deployed a ''supersonic'' parachute. When the rover separated from the parachute, rocket motors slowed the descent further. At 60 feet about the ground, a ''sky crane'' lowered the rover gently to the surface. This scenario had been carefully modeled at JPL of course, but no one knew if it would really work.