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Credit: NASA Marshall Space Flight Center
From mapping out the track of a hurricane to monitoring the melting of ice caps, satellites are heavily relied on in science — but sometimes they can go awry. The out-of-control Upper Atmosphere Research Satellite (UARS), which has been languishing in orbit for six years, is now on the verge of falling back to Earth, NASA announced in September 2011. In the above photo, the UARS hangs in the grasp of the Remote Manipulator System during deployment from Space Shuttle Discovery in September 1991.