NASA's Mars 2020 rover stands on its wheels for the first time

The Mars 2020 rover has reached a critical milestone in its design and development. After years of design, analysis, and testing, the rover is on its wheels for the first time. The titanium legs of the rover are the black tubes that stick out the side.The six wheels are made of aluminum and measure 20.7-inches in diameter. Each of those six wheels is machined with traction-providing cleats. The wheels are engineering version that will be replaced with flight wheels next year. Each wheel of the Mars 2020 rover has its own motor, and the two front and rear wheels have steering servos that allow the vehicle to turn 360-degrees in place.

The rover can move over rough terrain thanks to a "rocker-bogie" suspension system that has multiple pivot points and struts. While the rover will avoid terrain that makes it tilt more than 30 degrees, it can handle a 45-degree tilt. Now that the rover is on its wheels, it has been shipped from the JPL Spacecraft Assembly Facility to the Simulator Building for testing.

Mars 2020 will collect samples for a future return to Earth. Because of this, the team says that it must meet "extraordinary cleanliness measures" so that it won't contaminate any Mars samples with terrestrial contaminants. The rover has to be kept clean in assembly, in testing, and in moves between buildings.

To keep the rover clean during the move between the assembly and testing buildings it was packaged in foil. The team wiped the rover with a 70% isopropyl alcohol, and it will be moved into the vacuum chamber for surface thermal testing to see how its instruments operate in the frigid, near-vacuum environment on Mars. Mars 2020 is sent to land at Jezero Crater on February 12, 2021.