NASA’s Kepler Space Telescope, which spent nine years in deep space collecting data that detected thousands of exoplanets, has run out of fuel needed for further science operations. NASA has decided to retire the spacecraft within its current, safe orbit, away from Earth.
Launched on March 6, 2009, the Kepler space telescope revealed that there is statistically at least one planet around every star in our Milky Way Galaxy.
It also opened our eyes to the variety of worlds beyond our Solar System, with its discovery of more than 2,600 planets orbiting other stars.
Kepler also characterized a class of planets that don’t exist in our Solar System: planets between the sizes of Earth and Neptune, or ‘super-Earths.’
“As NASA’s first planet-hunting mission, Kepler has wildly exceeded all our expectations and paved the way for our exploration and search for life in the Solar System and beyond,” said Dr. Thomas Zurbuchen, associate administrator of NASA’s Science Mission Directorate in Washington.
“Not only did it show us how many planets could be out there, it sparked an entirely new and robust field of research that has taken the science community by storm. Its discoveries have shed a new light on our place in the Universe, and illuminated the tantalizing mysteries and possibilities among the stars.”
“When we started conceiving this mission 35 years ago, we didn’t know of a single planet outside the Solar System,” said Kepler’s founding principal investigator Dr. William Borucki, now retired from NASA’s Ames Research Center.
“Now that we know planets are everywhere, Kepler has set us on a new course that’s full of promise for future generations to explore our Galaxy.”
Kepler combined cutting-edge techniques in measuring stellar brightness with the largest digital camera outfitted for outer space observations at that time.
Originally positioned to stare continuously at 150,000 stars in one star-studded patch of the sky in the constellation Cygnus, the telescope took the first survey of planets in the Milky Way and became NASA’s first mission to detect Earth-size planets in the habitable zones of their stars.
“The Kepler mission was based on a very innovative design. It was an extremely clever approach to doing this kind of science,” said Dr. Leslie Livesay, director for astronomy and physics at NASA’s Jet Propulsion Laboratory, who served as Kepler project manager during mission development.
“There were definitely challenges, but Kepler had an extremely talented team of scientists and engineers who overcame them.”
In 2012, Kepler completed its primary mission and was awarded an extension.
After the failure of a second gyroscope that kept the spacecraft steady in 2013, NASA engineers found a way to use solar pressure to keep the spacecraft temporarily pointed in a desired direction.
“We know the spacecraft’s retirement isn’t the end of Kepler’s discoveries,” said Kepler project scientist Dr. Jessie Dotson, of NASA’s Ames Research Center.
“I’m excited about the diverse discoveries that are yet to come from our data and how future missions will build upon Kepler’s results.”
Before retiring the spacecraft, scientists pushed Kepler to its full potential, successfully completing multiple observation campaigns and downloading valuable science data even after initial warnings of low fuel.
The latest data, from Campaign 19, will complement the data from NASA’s newest Transiting Exoplanet Survey Satellite (TESS), launched in April 2018.