Mars Pathfinder was the first spacecraft to land on the surface of the red planet since the Viking mission in 1976. It was launched on December 4, 1996. On reaching Mars on July 4, 1997, the spacecraft entered the planet's thin atmosphere, was slowed by a parachute and then rockets, and then landed by bouncing on inflated airbags. Once on the surface, the protective aeroshell unfolded to provide three flat platforms and ramps, one of which held a rover (Sojourner). The Sojourner rover traveled down one of the ramps and proceeded to take close up images of the surface using two black and white cameras on the front and a color camera on the rear. The rover also featured a rear-mounted Alpha Proton X-ray Spectrometer that provided bulk elemental composition data on surface soils and rocks.

The Marie Curie rover was the flight spare for the Sojouner rover. During Sojourner's activites on Mars, engineers operated Marie Curie in the same movements in a Mars-like test area at the Jet Propulsion Laboratory (JPL) in California. For a time, NASA planned to send Marie Curie on a 2001 Mars mission, but this did not occur. Today, these two rovers--one still on Mars and its twin here--represent the first successful exploration of the Martian surface with a moving vehicle.

JPL transferred the Marie Curie rover to the Museum in 2015.