After over four years in orbit, the Kepler Space Telescope has racked up an impressive number of discoveries, and scientists still haven't plumbed the depths of the data it has collected, but it looks like its days of planet hunting are likely over.
NASA engineers just finished two weeks of tests on the telescope's reaction wheels, which help the telescope to stabilize its mirrors so that it can pick up the tiny fluctuations in the light of stars that mark the transit of a planet across our view of the star.
The telescope has four gyroscope-like wheels total. One of these wheels failed due to increased friction last July, and then a second one failed in May of this year. The telescope could get by with three wheels, but it can't continue its mission with only two.
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During the two weeks of tests, the Kepler team attempted to get at least one of the wheels back in operation, but unfortunately their efforts were unsuccessful.
With the telescope otherwise functional, NASA has no plans to scrap it completely, but they're now looking to give it a new mission. A call has gone out for scientific papers proposing new uses for the space telescope, and the Kepler team will review all of these ideas soon. Some possibilities: the telescope's sensitive mirrors could end up looking for near-Earth asteroids, or it could be given a new planet-hunting mission.
To date, the telescope has discovered 135 confirmed planets orbiting around other stars, with over 3,500 planet candidates still waiting to be confirmed, and that's just from the first half of the data collected by Kepler.
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Some of the most amazing discoveries by the telescope were announced back in April:
"Kepler has made extraordinary discoveries in finding exoplanets including several super-Earths in the habitable zone," said John Grunsfeld, the associate administrator for NASA's Science Mission Directorate in Washington, according to a NASA press release. "Knowing that Kepler has successfully collected all the data from its prime mission, I am confident that more amazing discoveries are on the horizon."
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