After months of experimentation, the Kepler Space Telescope team is ending its efforts to restore the spacecraft to full working order. The team will conduct a study to identify possible science opportunities for the spacecraft in its current condition. Two of Kepler's four gyroscope-like reaction wheels, which are used to precisely point the spacecraft, have failed. Efforts to restore at least one of the wheels have been unsuccessful.
Kepler completed its prime mission in November 2012 and began its four-year extended mission at that time. The spacecraft needs three functioning wheels to continue its search for Earth-sized exoplanets, which are planets outside our solar system, orbiting stars like our sun in what's known as the habitable zone -- the range of distances from a star where the surface temperature of a planet might be suitable for liquid water. As scientists analyze previously collected data, the Kepler team also is looking into whether the space telescope can conduct a different type of science program, potentially including an exoplanet search, using the remaining two good reaction wheels and thrusters.
From the data collected in the first half of its mission, Kepler has confirmed 135 exoplanets and identified over 3,500 candidates. The team continues to analyze all four years of collected data, expecting hundreds, if not thousands, of new discoveries including the long-awaited Earth-size planets in the habitable zone of sun-like stars.
Read the full story on NASA's website.