Recovering from the Mars Observer loss of 1993 was a top priority. A complete set of spares for a re-flight of the mission existed, but the cost of a second Titan III launch rocket was too expensive. Goldin ordered the planetary program to devise all of its future missions around the capabilities of the much less expensive (and much smaller) Delta 2. So Lockheed-Martin Astronautics of Denver proposed re-flying five of Mars Observer's eight experiments using the spare electronics, a new spacecraft bus and the aerobraking technique. This became the Mars Global Surveyor mission.
Mars Global Surveyor was launched Nov. 7, 1996, with a cost under-run of about $2 million. It started aerobraking in September 1997, and its flight team expected to achieve its science orbit six months later. But during one of the aerobraking passes, one of the solar panels started flexing in the air flow too much, and the team had to slow the process to protect it. The flaw was traced to a part that had cracked shortly after launch. So aerobraking lasted until February 1999.
Global Surveyor, however, then lasted far beyond its designed life. Still operating in 2006, it produced mineralogical and magnetic field maps of the Mars surface. It also provided thousands of spectacular high-resolution images. Its data suggested Mars had once had plate tectonics as Earth still does, and that the surface is still being altered on occasion by water from subsurface ice.
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