HyperbolicParabaloid writes "According to the New York Times, an equipment failure on the Kepler spacecraft may mean the end of its planet-hunting mission. One of the reaction wheels that maintains the craft's orientation — critical to long-exposure imaging — has failed. 'In January engineers noticed that one of the reaction wheels that keep the spacecraft pointed was experiencing too much friction. They shut the spacecraft down for a couple of weeks to give it a rest, in the hopes that the wheel’s lubricant would spread out and solve the problem. But when they turned it back on, the friction was still there. Until now, the problem had not interfered with observations, which are scheduled to go on until at least 2016. Kepler was launched with four reaction wheels, but one failed last year after showing signs of erratic friction. Three wheels are required to keep Kepler properly and precisely aimed. Loss of the wheel has robbed it of the ability to detect Earth-size planets, although project managers hope to remedy the situation. The odds, astronomers said, are less than 50-50.'"