Mars Pathfinder and Sojourner

The Mars Pathfinder and the Rover, Sojourner

Pathfinder landed on Mars on July 4, 1997.  It used a parachute to slow its fall to the surface and then used airbags to cushion the completion of the descent.  This was the first time that the idea of the "airbag technique" had been used.  The landing site, on the northern hemisphere, was originally a place on Mars where liquid water was formerly present.  This place was referred to as "Ares Vallis" and is one of the rockiest sections of Mars.  Landing here meant that there would be a lot of rocks to research and was thought to be a fairly safe landing and site.

The rover got its name from a contest where anyone could write in and offer suggestions.  Its name eventually was chosen and it was Sojourner.  This came from a civil rights activist named Sojourner Truth.  The measurements of Sojourner were approximately 65 centimeters long x 48 centimeters wide x 30 centimeters tall. 

Sojourner discovered 2.3 billion pieces of information during its mission.  There were 16,500 images from the lander and 550 from Sojourner.  Every day had a different experiment.  There was even a test trial to see how fast the rover would move on the Martian surface.  Amazingly, it went 1 centimeter/second  or 2 feet/minute.   

Besides the primary energy source of the solar panel on her back, Sojourner had non-rechargeable lithium thionol chloride D-cell-size batteries.  This allowed for numerous days without solar energy.  

During its missions, the rover traveled around and scientists named different rocks as landmarks.  For instance, Barnacle Bill, Yogi, and Scooby Doo.  The Pathfinder lander outlived its life by three missions and Sojourner outlived her life by twelve times. 

For more information, check out The Mars Pathfinder and experience the exciting first moments.