The revolutionary planet-hunting activities of NASA's prolific Kepler space telescope have come to an end.
NASA has given up hope of restoring the Kepler spacecraft to full health and is now attempting to determine what the observatory can accomplish in its compromised state, agency officials announced today (Aug. 15).
"We are now moving on to the next phase of Kepler's mission, because that's what the data requires us to do," Paul Hertz, director of NASA's astrophysics division, told reporters during a press conference today. "This is not the last you'll hear from Kepler. There's a huge amount of data collected that we'll continue to analyze." [Gallery: A World of Kepler Planets]
The $600 million Kepler mission launched in March 2009 on a 3.5-year prime mission to determine how commonly Earth-like planets occur around the Milky Way galaxy.
Kepler detects exoplanets by noting the tiny brightness dips caused when these worlds cross in front of, or transit, their parent stars. The observatory needs three working reaction wheels — gyroscope-like devices that maintain Kepler's position in space — to do this precision work.
Kepler had four of these wheels when it launched — three for immediate use and one spare. But one wheel, known as number 2, failed in July 2012. And then wheel four conked out on May 11 of this year, halting the spacecraft's planet hunt.
Mission engineers have since managed to get those two malfunctioning wheels spinning again, but both of them still exhibit too much friction to support Kepler's fine-pointing work. So the observatory's original mission is over, officials said today.
"We do not believe that we can recover three-wheel operations, or Kepler's original science mission," Hertz said.
Sending astronauts out to fix Kepler, as was done five times with NASA's Hubble Space Telescope, is not an option. That's because Kepler orbits the sun rather than Earth and is currently millions of miles from our planet.