This recent update about Kepler really made me sad…
“At our semi-weekly contact on Tuesday, May 14, 2013, we found the Kepler spacecraft once again in safe mode. As was the case earlier this month, this was a Thruster-Controlled Safe Mode. The root cause is not yet known, however the proximate cause appears to be an attitude error. The spacecraft was oriented with the solar panels facing the sun, slowly spinning about the sun-line. The communication link comes and goes as the spacecraft spins.
We attempted to return to reaction wheel control as the spacecraft rotated into communication, and commanded a stop rotation. Initially, it appeared that all three wheels responded and that rotation had been successfully stopped, but reaction wheel 4 remained at full torque while the spin rate dropped to zero. This is a clear indication that there has been an internal failure within the reaction wheel, likely a structural failure of the wheel bearing.”
The data from Kepler have revealed hundreds of confirmed planets, and there are thousands more planet candidates (potential planets that have been detected but not yet confirmed). Kepler has found planets more massive than Jupiter, multiplanetary systems with Earth-sized (or even smaller) planets. It’s also found planets in the habitable zones of their stars.
Kepler had successfully completed its primary 3,5 year mission. Later, this mission was extended in 2012.
The mission has substantial quantities of data in the archives that are yet waiting to be fully analyzed, and the string of scientific discoveries is expected to continue for years to come.