The Kepler Space Telescope, which is responsible for the detection of 2,245 exoplanets and 2,342 others to be confirmed, is running out of fuel. The telescope has only a few months left until his lights go out. The spaceship will go down in history as one of the greatest astronomical tools ever used.
Kepler is a formidable hunter of exoplanets. Robust, it will have resisted many failures. But after 9 years of flying and making countless discoveries, fuel is running out. “So, while we anticipate flight operations ending soon, we are prepared to continue as long as the fuel allows,” says Charlie Sobeck, Kepler Space Telescope System Engineer. “Our current estimates are that Kepler’s tank will run dry within several months – but we’ve been surprised by its performance before!”
Why surprised? Because an incident in 2013 nearly put the spaceship out of action. It had suffered a mechanical failure rendering it unable to maintain its gaze on the original field of view. However, mission planners had managed to save the telescope using the pressure of sunlight to maintain its pointing. This second phase of the mission, called K2, required Kepler to examine each part of space every three months. These quarterly adjustments are dubbed “campaigns” by NASA, which estimated at the time, that Kepler would be able to perform only 10 campaigns before running out of fuel. Against all odds, phase K2 has already completed 16 campaigns, and is currently in the middle of its 17th.. Thus, it’s possible to send a spaceship to supply it. The researchers will then try to get the most out of Kepler over the next few months, making sure that it sends all its data back to Earth. Once there is no more fuel, the ship will be abandoned and left adrift. The telescope is not equipped with a fuel gauge, so Kepler’s team will look for warning signs of its imminent death, such as a pressure drop in the fuel tank or poor performance of its thrusters.
Once Kepler is out of use, astronomers will nevertheless continue to study its data for many years. As mentioned before, there are still thousands of potential exoplanets to confirm. As for the next generation, it will soon be provided by TESS, whose launch is scheduled for Cape Canaveral on April 16th. Its mission will be to detect the terrestrial planets that gravitate in the habitable zone around the stars. To achieve this, the space observatory — which uses the method of detection of transits — will observe the whole sky focusing on the brightest stars, on average 30 to 100 times more than those observed by the Kepler space telescope.