The Mars Pathfinder is the second mission in the Discovery Programme, a NASA initiative for planetary missions, developed in three years for $150 million. The mission is regarded by NASA as an engineering demonstration of key technologies for future Mars landers.

The Pathfinder will be used to investigate the structure of the Martian atmosphere, surface meteorology, surface geo- logy, form, and structure, and the elemental composition of Martian rocks and soil, using its own instruments and those aboard the Sojourner rover.

Upon arrival at Mars on 4 July, 1997, the 870kg spacecraft will enter the Martian atmosphere, deploying the parachute, rocket-braking system and air-bag system for a soft, upright landing on Ares Vallis, 19.5íN/32.8íW, an outflow of what was once a river valley. Data will be gathered for 30 days by the 325kg lander, while the 16kg, six-wheeled rover will be deployed for autonomous seven-day operations. The National Research Council has observed, however, that the Mars Pathfinder has "restricted instruments, lack of mobility and no system to produce images during the landing", echoing concerns about future missions.

Source: Flight International