Mars Pathfinder was launched on December 4, 1996, and landed on Mars seven months later, on July 4, 1997. As it entered the Martian atmosphere, it was greatly slowed by a heat shield, a parachute, and rockets. Its impact on the surface was cushioned by an enveloping cluster of air bags, on which it bounced to a halt, the first time a landing type like this one had been tried. Its landing site in Ares Valles, was at the mouth of a large flood channel.
The spacecraft consisted of two small elements, 816 pound lander and a 23 pound rover. Once on the surface, the lander was formally named the Carl Sagan Memorial Station after the 20th-century American astronomer. The rover was named Sojourner in honour of the 19th-century African American civil rights advocate Sojourner Truth.
The six-wheeled Sojourner carried two black-and-white cameras used for navigating the surface, one color camera, and an alpha proton X-ray spectrometer for determining the composition of rocks and soil. Its maximum speed was 1 cm per second or 2 feet per minute. It rolled down a ramp from the lander on July 5 and over the next 2 1/2 months explored the vicinity of the landing site, collecting data on soil and several individual rocks. Sojourner relayed 550 images to Earth, and the Lander sent 16,500 pictures back to Earth. The missions main goals were to futher understand the surface geology, geochemistry of surface materials and atmospheric structure, and near surface meteorology.  In the missions 85 days of being active it completed everything it was asked to do and more.  The end of the mission was September 27th, 1997.