NASA's planet-hunting mission may be under threat after a piece of equipment keeping a key telescope's position in space failed. Since its launch in 2009, Kepler has helped identify more than 130 new planets.
NASA announced that the spacecraft had lost the second of its four wheels, which control how it orients in space. Kepler is unable to point at stars with the same precision with only two working wheels left.
The telescope was designed to gaze at about 100,000 distant sunlike stars, searching for planets that pass by or transit in its line of sight. Because Kepler is in orbit around the sun, about 65 million kilometers (40 million miles) away from earth, it is too far away to send astronauts on a repair mission.
In the next few weeks, engineers on the ground will try to start ways to restart the faulty wheel or work out ways to use Kepler for other purposes if its ability to track down planets is finished.
Launched in 2009 in a mission costing $600 million (466 million euros), the space telescope has identified 132 confirmed planets and more than 2,000 potential ones, including a handful that look similar to Earth.
NASA is not ready to call it quits. "I wouldn't call Kepler down-and-out just yet," said sciences chief John Grunsfeld.
No decision had yet been made to end the mission's data collection, the space agency announced in its statement.
"Even if data collection were to end, the mission has substantial quantities of data on the ground yet to be fully analyzed, and the string of scientific discoveries is expected to continue for years to come," the statement read.
jr/msh (AP, Reuters, dpa)