For the past few months, the clean room floor in High Bay 1 at NASA's Jet Propulsion Laboratory in Pasadena, California, has been covered in parts, components and test equipment for the Mars 2020 spacecraft, scheduled for launch toward the Red Planet in July of 2020. But over the past few weeks, some of these components—the spacecraft-rocket-laden landing system and even the stand-in for the rover (christened "surrogate-rover") - have seemingly disappeared.