Which rocket launched NASA's Sojourner rover toward Mars in 1996?

NASA’s Sojourner rover was launched toward Mars aboard a Delta II 7925 rocket. More specifically, the launch vehicle is often identified as a Delta II 7925 D-240, but “Delta II 7925” is the canonical answer used in mission summaries.

The launch took place from Cape Canaveral Launch Complex 17B on December 4, 1996. The rocket carried the Mars Pathfinder spacecraft, whose lander later delivered Sojourner to the Martian surface. The rover and lander were therefore part of one Pathfinder payload rather than separate launches.

Delta II was a reliable expendable launch-vehicle family developed from the earlier Delta rocket line. Its designation encoded the vehicle configuration, including the 7925 model and its solid rocket boosters. The D-240 suffix identified the particular mission configuration.

Mars Pathfinder reached Mars on July 4, 1997, after a journey of about seven months. The lander used airbags to settle onto the surface, then deployed Sojourner, making it the first successful wheeled vehicle to operate on another planet.