However, Kepler has completely run out of fuel now and thus will not be able to carry out further operations.
Kepler confirmed a trove of 2,681 planets outside our solar system.
"The Kepler mission has paved the way for future exoplanet studying missions".
"We know the spacecraft's retirement isn't the end of Kepler's discoveries", said Jessie Dotson, Kepler's project scientist at NASA's Ames Research Centre in California's Silicon Valley. This enabled an extended mission for the spacecraft, dubbed K2, which lasted as long as the first mission and bumped Kepler's count of surveyed stars up to more than 500,000.
Now 94 million miles from Earth, Kepler should remain in a safe, stable orbit around the sun.
Its positioning system broke down in 2013, though scientists found a way to keep it operational.
Mission engineers are preparing to turn off the spacecraft's radio transmitters, leaving it to forever orbit around the Sun.
Kepler continued to hunt for planets during its K2 phase. It was meant to last for three and a half years and ended up sticking around for nearly 10.
NASA/JPL-Caltech/BallNASA's Kepler space telescope, built in part by Ball Aerospace, before its launch in 2009. The 19-year-old Chandra X-ray Telescope's pointing system also ran into trouble briefly in October. NASA announced it would "retire" Kepler as a result.
Pakistan's 'father of the Taliban' cleric killed in knife attack
He was killed by unidentified attackers in a house where he was staying, his son was quoted as saying by the report. He also led the Darul Uloom Haqqania seminary in Khyber Pakhtunkhwa's Akora Khattak, Dawn reported.
During its 18+ observation campaigns the telescope tallied literally thousands of exoplanet discoveries. It is a possible "water world" the size of Earth, perhaps covered with oceans and with a water-based atmosphere.
A series of huge new terrestrial telescopes now under construction will also be able to analyze exoplanet atmospheres spectroscopically, and look for signs of life such as the presence of oxygen gas and water vapor.
Kepler's data also provided a new way to assess whether a planet had a solid surface, like Earth and Mars, or is gaseous, like Jupiter and Saturn.
Discovery Of Earth 2.0.
Kepler helped astronomers measure potential planets by glimpsing transits, or moments when planets passed in front of their stars. The satellite is now on its 2-year mission worth $337 million.
The telescope is now scanning 85% of the night sky, staring down distant solar systems and hunting for small, rocky, Earth-like planets in the process.
The new spacecraft will focus on nearby exoplanets, those in the range of 30 to 300 light-years away.
Two-third of the planets discovered so far are thanks to Kepler's observations. If Kepler's search area was like a shotgun blast, then that of TESS is an exploding grenade or bomb. "I look forward to the odd, fantastic worlds we're bound to discover". The most recent analysis of Kepler's discoveries concludes that 20 to 50 percent of the stars visible in the night sky are likely to have small, possibly rocky, planets similar in size to Earth, and located within the habitable zone of their parent stars. In this century, the number of known exoplanets has exploded in size, mainly due to this spacecraft, NASA's Kepler space telescope, which was specifically designed as a planet-hunter.
The Hubble Space Telescope and Chandra X-Ray Observatory experienced technical problems earlier this month that have since been fully repaired.