LOS ANGELES - NASA's Kepler planet-hunting telescope is broken, potentially jeopardizing a mission that opened up new possibilities on life outside the solar system.
If engineers can't find a fix, the malfunction could mean an end to the $600 million mission's planet search, although the space agency wasn't ready to call it quits Wednesday.
"I wouldn't call Kepler down-and-out just yet," said NASA sciences chief John Grunsfeld.
NASA said the spacecraft lost the second of four wheels that control the telescope's orientation in space. Over the next few weeks, engineers will try to repair the wheel or find another solution. The telescope could be used for other purposes even if it can no longer track down planets.
Kepler was launched in 2009 in search of Earth-like planets. So far, it has confirmed 132 planets and spotted more than 2,700 potential ones. So far only two planets seem like ideal places for some sort of life to flourish.
While ground telescopes can hunt for planets outside our solar system, Kepler is much more advanced.
For the past four years, Kepler has focused its telescope on a patch of the Milky Way with more than 150,000 stars, recording slight dips in brightness - a sign of a planet passing in front of the star.
Now, "We can't point where we need to point. We can't gather data," deputy project manager Charles Sobeck told The Associated Press.
Sobeck said there's a backlog of data that scientists still need to analyze even if Kepler's planet-hunting days may be numbered.
Last month, astronomers announced Kepler's discovery of two distant worlds that are the best candidates for habitable planets.
The other planets found by Kepler haven't fit all the criteria that would make them right for life of any kind - from microbes to humans.
Kepler telescope: kepler.nasa.gov