Classification: Rover spacecraft.
Mission: Analyze Martian soil and individual rocks.
Features: Sojourner weighs 11.0 kg on Earth and is about the size of a child's small wagon. It has six wheels and can move at speeds up to 0.6 meters per minute. The rover's wheels and suspension use a rocker-bogie system that is unique in that it does not use springs. Rather, its joints rotate and conform to the contour of the ground, providing the greatest degree of stability for traversing rocky, uneven surfaces.
Sojourner performed a number of science experiments to evaluate its performance as a guide to the design of future rovers. These included conducting a series of experiments that validate technologies for an autonomous mobile vehicle; deploying an Alpha Proton X-ray Spectrometer on rocks and soil; and imaging the lander as part of an engineering assessment after landing.
Also, Sojourner performed a number of specific technology experiments as a guide to hardware and software design for future rovers as well as assisting in verifying engineering capabilities for Mars rovers.
Stabilization: Spin stabilized during cruise.
See also: Mars Microrover website.