On Nov. 7, 1996, NASA launched its Mars Global Surveyor mission. This was the first mission NASA sent to Mars in almost 20 years!
The Mars Global Surveyor spacecraft was an orbiter. It transmitted data from NASA's Mars rovers Sojourner, Spirit and Opportunity back to Earth. The spacecraft also did a lot of its own science. It found surface channels on Mars that appeared to have been created by running water.
Mars Global Surveyor looked at the south pole of Mars and saw signs of possible climate change. It also saw a mineral called hematite on Mars. Hematite usually forms in water. NASA then sent its Spirit and Opportunity rovers to look for the hematite, and both rovers found it near their landing sites.
Mars Global Surveyor survived much longer than expected. But a space maneuver accidentally exposed one of its batteries to the sun, and the spacecraft lost power. It fell silent forever in November 2006.
Why it mattered
As the first successful Mars mission since the two Viking launches in 1975, Mars Global Surveyor ushered in a new era of exploration of the Red Planet, not only through its own contributions to orbit-based science, but by serving a relay for surface-based rovers. As such, it became a primary pipeline for multiple concurrent Mars missions.
"The [Mars Global Surveyor] mission overhauled scientists' understanding of Mars by studying the entire Martian surface, atmosphere and interior. Major findings included dramatic evidence that water still flows on Mars in short bursts down hillside gullies, and the identification of water-related mineral deposits leading to selection of a Mars rover landing site for a subsequent mission," read a NASA description of the probe.
Mars Global Surveyor sent back more than 240,000 images to Earth during its nine active years.
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