Which NASA mission was the first to use a rover on Mars?

NASA’s Mars Pathfinder was the first mission to use a rover on Mars.

Mars Pathfinder landed in Ares Vallis on July 4, 1997. Its lander carried Sojourner, a small six-wheeled rover that investigated rocks and soil near the landing site. Sojourner was remotely operated from Earth and could travel short distances around the lander.

The mission demonstrated an innovative airbag landing system and relatively low-cost technologies for planetary exploration. Sojourner used instruments to analyze the composition of Martian rocks and helped scientists study the region’s history of water-related floods.

Viking landers had already operated on Mars in the 1970s, but they were stationary. Later NASA rovers, including Spirit, Opportunity, Curiosity, and Perseverance, were much larger and more capable. Mars Pathfinder therefore marks the beginning of NASA’s successful mobile rover era on Mars.