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Mars Pathfinder Sojourner Rover

The Mars Pathfinder Sojourner Rover, a lightweight machine on wheels, accomplished a revolutionary feat on the surface of Mars. For the first time, a thinking robot equipped with sophisticated laser eyes and automated programming reacted to unplanned events on the surface of another planet.

After a few days on the Martian surface the NASA controllers turned on Sojourner's hazard avoidance system and asked it to start making some of its own decisions. This hazard avoidance system set the rover apart from all other machines that have explored space. Sojourner made trips between designated points without the benefit of detailed information to warn it of obstacles along the way

Sojourner moved slowly at one and one half feet per minute and stopped a lot along the way to sense the terrain and process information, but there was no hurry on Mars which is not visited very often.

Sojourner was carried to Mars by Pathfinder which launched on December 4, 1996 and reached Mars on July 4, 1997, directly entering the planet's atmosphere and bouncing on inflated airbags.

Sojourner was designed by a large NASA team lead by Jacob Matijevic and Donna Shirley.

Sojouner traveled a total of about 100 meters (328 feet) in 230 commanded maneuvers, performed more than 16 chemical analyses of rocks and soil, carried out soil mechanics and technology experiments, and explored about 250 square meters (2691 square feet) of the Martian surface. During the mission, the spacecraft relayed an unprecedented 2.3 gigabits of data, including 16,500 images from the lander's camera, 550 images from the rover camera, 16 chemical analyses of rocks and soil, and 8.5 million measurements of atmospheric pressure, temperature and wind.

The flight team lost communication with the Sojouner September 27, after 83 days of daily commanding and data return. In all, the small 10.5 kilogram (23 lb) Sojouner operated 12 times its expected lifetime of seven days.