NASA’s Kepler Spacecraft in Jeopardy After #4 Reaction Wheel Malfunction

NASA’s planet-hunting Kepler spacecraft has been crippled by the failure of one of the reaction wheels that keep it pointed, the space agency is announcing this afternoon, according to astronomers close to the situation.

Earlier a statement from Kepler's Command Team stated;

"Kepler’s reaction wheel #4 continues to exhibit signs of elevated friction levels and occasional torque spikes that appear to indicate a deterioration of the wheel bearing. "

"The team is able to monitor general wheel performance twice weekly during scheduled X-band engineering contacts, but must rely on the high rate monthly downlinks for detailed insight."

"All appropriate mitigation steps to prolong wheel life have now been taken. While the wheel may still continue to operate for some time yet, the engineering team has now turned its attention to the development of contingency actions should the wheel fail sooner, rather than later."

"Initially, these contingencies will focus on preserving fuel, but subsequent goals will be to return the failed wheels to service, perhaps at reduced performance levels, and investigating opportunities for gathering science data using a combination of wheels and thrusters."

The Kepler Team is now facing the worst case scenario, whereby the Kepler telescope's Guidance System  is now severely compromised.

If engineers cannot restore the wheel or find some other way to keep the spacecraft’s telescope pointed, it could spell a premature end to one of the most romantic and successful of NASA’s missions: the search for Earth-like planets in habitable orbits around other stars.

Just last month, astronomers reported that Kepler had found two planets only slightly larger than Earth orbiting in the “Goldilocks” zone, where liquid water is possible, of a star 1,200 light-years from here.

More planet candidates, even smaller and closer to being Earth-like, lurk in the pipeline, astronomers say, but they have not yet been confirmed.