In this time-lapse video, taken on Oct. 4, 2019, at NASA's Jet Propulsion Laboratory in Pasadena, California, bunny-suited engineers remove the inner layer of protective antistatic foil on the Mars 2020 rover after the vehicle was relocated from JPL's Spacecraft Assembly Facility to the Simulator Building for testing.

"The Mars 2020 rover will be collecting samples for future return to Earth, so it must meet extraordinary cleanliness measures to avoid the possibility of contaminating Martian samples with terrestrial contaminants," said Paul Boeder, contamination control lead for Mars 2020 at JPL.

"To ensure we maintain cleanliness at all times, we need to keep things clean not only during assembly and testing, but also during the moves between buildings for these activities."

After removing the first layer of antistatic foil (just prior this time-lapse), the teams used 70% isopropyl alcohol to meticulously wipe down the remaining layer, seen here, along with the trailer carrying the rover.

Later that day, the rover was moved into the larger main room of the Simulator Building. In the coming weeks, the rover will enter a massive vacuum chamber for surface thermal testing – a weeklong evaluation of how its instruments, systems and subsystems operate in the frigid, near-vacuum environment it will face on Mars.