Kepler's antenna must be pointed toward Earth to get the most recent observations back.
"The Kepler team is planning to collect as much science data as possible in its remaining time and beam it back to Earth before the loss of the fuel-powered thrusters means that we can't aim the spacecraft for data transfer".
Almost out of fuel after nine years of trail-blazing searches for exoplanets, NASA's' Kepler satellite has been put in a state of electronic hibernation in preparation for downloading stored data from its latest observation campaign.
The ultra-sensitive CCD sensors making up the Kepler Space Telescope's camera are created to look for the slight dimming of a star's brightness that might indicate a planet passing in front as viewed from Earth. According to NASA, May 12 marked the start of Kepler's 18th observational campaign, which involved focusing on the Cancer constellation. "On Aug. 2, the team will command the spacecraft to awaken from its no-fuel-use state and maneuver the spacecraft to the correct orientation and downlink the data". Astronomers hope that this information will provide the opportunity to confirm the existence of new exoplanets. What makes Tatooine one of the most weird exoplanets ever found is that it is orbiting two host stars which make it be a circumbinary planet. Most notable, in 2013, a malfunctioned reaction wheel on the spacecraft prevented it from being stable required NASA to readjust the mission for the Kepler.
NASA's Kepler mission has discovered a world where two suns set over the horizon instead of just one. The agency has been monitoring the Kepler spacecraft closely for signs of low fuel, and expects it to run out of fuel in the next few months. Refueling the spacecraft is not an option; Kepler orbits the sun, not Earth, and it's now millions of miles from our planet. The space telescope will then begin its 19th campaign with its remaining fuel.
Kepler's "replacement" is the Transiting Exoplanet Survey Satellite (TESS), which has a lofty goal of finding 20,000 new exoplanets.
Reborn as "K2", this extended mission requires the spacecraft to shift its field of view to new portions of the sky roughly every three months in what scientists refer to as a "campaign". This is a part of Kepler's "K2" mission started in 2014.
The spacecraft was given a new lease on life by using the pressure of sunlight to maintain its pointing, like a kayak steering into the current.