Mars Pathfinder

Mars Pathfinder

Courtesy of NASA

Mars Pathfinder landed in a rocky area of Mars. Contained inside the spacecraft was a robotic rover vehicle, Sojourner, which rolled down a ramp and out onto the Martian surface to travel around and explore. Both lander and rover carried out scientific experiments and returned more data than expected.

December 4, 1996

July 4, 1997

End of Mission
(last communication) September 27, 1997; March 10, 1998

Demonstrate key engineering technologies and concepts for use in future missions to Mars. Deliver science instruments to the surface of Mars to investigate the structure of the atmosphere, surface meteorology, surface geology, as well as the form, structure, and elemental composition of rocks and soil.

Pathfinder used the first rover to explore the Martian surface. It returned more than 16,000 images from the lander and 550 images from the rover and extensive data on winds and other weather factors. Images revealed a rocky plain, about 20% of which was covered by rocks, that appears to have been deposited and shaped by catastrophic floods. The AXPS (Alpha Proton X-ray Spectrometer) instrument performed chemical analyses of several rocks and soils that showed a diversity of rock types at the landing site and a higher silica content than Martian meteorites. The soil chemistry of the landing site was similar to that found at the Viking 1 and 2 sites. Martian dust was discovered to be very fine, about one micron, and include magnetic particles. Evidence of wind abrasion of rocks and dune-shaped deposits was also found, indicating the presence of sand-sized particles.