One year later, in May 2014, NASA was able to fix the wheels and revive the mission; the agency estimated at the time that it would have had enough fuel to last until 2021:If Kepler's not dead, it's certainly a vegetable. Scientists controlling the spacecraft went to check on it Tuesday and found that one of its four reaction wheels, which let the telescope point at things it wants to see, wasn't responding. NASA went through the same thing last year, and hasn't been able to get that reactor wheel working. It needs at least three to function, and John Grunsfeld, who runs NASA's science mission directorate, said the telescope "is not in a place where I or any other astronaut can go up and rescue it."
Kepler really freaked everyone out in April 2016, when it unexpectedly switched to "emergency mode” and started burning fuel like crazy, 75 million miles from home. It was saved in part by NASA’s Deep Space Network:If everything goes smoothly, Kepler will begin looking for planets again by the end of the month and will operate for at least two more years. If it works, scientists on the project estimate that the telescope has roughly seven years worth of fuel left.
Given this track record, it’d be tempting to think that maybe there’s a tiny chance Kepler isn’t done yet. But it sounds like this is the finale for the little telescope that could.After Kepler's state of emergency was lifted, mission manager Charles Sobeck expressed his gratitude to the Deep Space Network, and "to other missions that surrendered their scheduled telemetry links.”