March 15 (UPI) -- NASA's most prolific planet hunter is nearing the end of its lifespan. The Kepler space telescope, an integral member of NASA's scientific satellite fleet, is running out of fuel.
"With nary a gas station to be found in deep space, the spacecraft is going to run out of fuel," Charlie Sobeck, system engineer for the Kepler space telescope mission, wrote in an update this week. "We expect to reach that moment within several months."
Kepler began its mission in 2009 and, for the majority of its time in space, the telescope's main mission has been to observe other planetary systems. The satellite has been integral to the discovery of exoplanets.
Kepler has, over the course of its scientific life, identified more than 5,000 exoplanet candidates. More than 2,500 of those exoplanets have been confirmed.
Life in space has been hard on Kepler. The observatory has been fried by cosmic rays and suffered several mechanical failures.
When its second reaction wheel broke in 2013, scientists thought Kepler's days of fielding valuable observations were over. The craft couldn't stabilize itself to point its cameras at cosmic targets. But scientists developed a fix, programming Kepler to use the pressure of solar particles streaming from the sun to stabilize itself.
The band-aid solution allowed Kepler to execute several more campaigns, collecting data for the study of supernovas, star formation, asteroids, comets and, of course, exoplanets.
Since 2013, Kepler's improvised stabilization has used up a lot of fuel and now the observatory finds itself running low. Because Kepler is far away from Earth and other satellites, scientists haven't made any special plans for the spacecraft's final goodbye.
While astronomers, both amateur and professional, will be sad when Kepler finally does say goodbye, NASA scientists are excited about their next-generation planet hunter.
While Kepler continues to bring us exciting data as it draws close the finish line, the Transiting Exoplanet Survey Satellite, TESS, will be launching on April 16 from Cape Canaveral, Florida," Sobeck wrote. "TESS will search nearly the entire sky for planets outside our solar system, focusing on the brightest stars less than 300 light-years away, and adding to Kepler's treasure trove of planet discoveries."