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Sojourner rover

Sojourner
Sojourner on Mars PIA01122.jpg
Mission type Mars rover
Operator NASA
Website Official website
Mission duration Planned: 7 sols (7 days)
Mission end: 83 sols (85 days)
From arrival on Mars
Spacecraft properties
Dry mass 11.5 kilograms (25 lb) (Rover only)
Start of mission
Launch date December 4, 1996, 06:58:07 UTC
Rocket Delta II 7925 D240
Launch site Cape Canaveral LC-17B
Contractor McDonnell Douglas
Deployed from Mars Pathfinder
Deployment date July 5, 1997 (1997-07-05)
End of mission
Last contact September 27, 1997 (1997-09-28)
Mars rovers (NASA)

Sojourner was the Mars Pathfinder robotic Mars rover that landed on July 4, 1997 in the Ares Vallis region, and explored Mars for around three months. It has front and rear cameras and hardware to conduct several scientific experiments. Designed for a mission lasting 7 sols, with possible extension to 30 sols, it was in fact active for 83 sols. The base station had its last communication session with Earth at 3:23 a.m. Pacific Daylight Time on September 27, 1997. The rover needed the base station to communicate with Earth, despite still functioning at the time communications ended.

Sojourner traveled a distance of just over 100 metres (330 ft) by the time communication was lost. It was instructed to stay stationary until October 5, 1997 (sol 91) and then drive around the lander.

The word Sojourner first appeared in print in the first Bible printed by Gutenberg in 1454-1455. It specifically deals with the travels of Abraham, formerly Abram. It is easily found in the first chapter of Genesis. It means "traveler", and was selected in an essay contest won by V. Ambroise, a 12-year-old from U.S. state of Connecticut. It is named for abolitionist and women's rights activist Sojourner Truth. The second-place prize went to Deepti Rohatgi, 18, of Rockville, MD, who proposed Marie Curie, a Nobel Prize-winning Polish chemist. Third place went to Adam Sheedy, 16, of Round Rock, TX, who chose Judith Resnik, a United States' astronaut and shuttle crew-member. The rover was also known as Microrover Flight Experiment abbreviated MFEX.

Sojourner has solar panels and a non-rechargeable battery, which allowed limited nocturnal operations. Once the batteries were depleted, it could only operate during the day. The batteries are lithium-thionyl chloride (LiSOCl2) and could provide 150 watt-hours. The batteries also allowed the health of the rover to be checked while enclosed in the cruise stage while en route to Mars.

0.22 square meters of solar cells could produce a maximum of about 15 watts on Mars, depending on conditions. The cells were GaAs/Ge (Gallium Arsenide/Germanium) and capable of about 18 percent efficiency. They could survive down to about −140° Celsius (−220 °F).


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Wikipedia

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