The U.S. space agency says it is ending its attempts to fix the Kepler
space telescope after engineers failed to repair two of the spacecraft's four reaction wheels. One of the wheels broke down in July of last year, while the second malfunctioned this past May.
NASA made the announcement Thursday, saying it is looking into whether the instrument can be used in a different capacity.
The telescope was launched in 2009 on a search for Earth-size planets in what is known as the "habitable zone," the region between a star and planet in which temperatures would permit liquid water and possibly life.
But after the two wheels failed, deputy project manager Charles Sobeck said NASA is ending its attempts to restore the spacecraft to full working order. The decision to call off the repair efforts followed a test last week. The wheels are used to precisely point the spacecraft.
"We’ve since recovered the spacecraft from safe mode back to its point rest state where we use thrusters in a very fuel-efficient manner to control the spacecraft, keep it power positive, keep the communications link open," he said. "But the results of that show what we expected to see, that the wheels are sufficiently damaged that they cannot sustain spacecraft pointing control for any extended period of time."
Kepler has discovered 135 exoplanets and more than 3,500 planet candidates with a wide range of sizes and orbital distances.
The Kepler team is now focusing on analyzing the data collected by the spacecraft over the past four years.
Although the spacecraft will no longer operate with its unparalleled precision pointing, scientists expect Kepler’s most interesting discoveries are still to come.