NASA’s Kepler Space Telescope Enters ‘Nap Mode’ To Save Up Its Last Remaining Fuel


After scouring the cosmos for nearly nine years in search for new worlds to discover, the Kepler Space Telescope has all but run out of gas and is essentially operating on fumes, astronomer James Davenport explains in the video below.

The spacecraft is expected to deplete the last of its fuel reserves within the next few months, thereby reaching the end of its long and fruitful mission.

Currently engaged in its 18th observation campaign, Kepler is now storing a bounty of data which the spacecraft has yet to send back to Earth for our scientists to decode and analyze.

To make sure that Kepler has enough fuel to send over the data, NASA has decided to put all science operations on hold and place its famous planet-hunting spacecraft in “nap mode,” in order to save up its last remaining fuel.

“Earlier this week, NASA’s Kepler team received an indication that the spacecraft fuel tank is running very low. NASA has placed the spacecraft in a hibernation-like state in preparation to download the science data collected in its latest observation campaign,” space agency officials wrote in a news release.

Sleeping Beauty

As Davenport points out, this “nap mode” is different from the original sleep mode that the spacecraft had and which used a lot of fuel to keep Kepler pointed in a safe direction. Meanwhile, this newly-instated hibernation mode involves absolutely no fuel usage, aiming to conserve whatever’s left for the downloading of science data.

“Returning the data back to Earth is the highest priority for the remaining fuel,” stated NASA.

According to Space News, the Kepler Space Telescope entered the “no-fuel-use safe mode” on July 2, after the space agency received reports of an “anomalous” drop in fuel pressure, and will remain in hibernation for exactly one month.

The spacecraft is due to wake up on August 2, when it will maneuver itself into the correct orientation in respect to Earth and down-link all the data collected so far during Campaign 18.

At the moment it entered the “nap mode,” Kepler was 51 days into the 82-day campaign, which began on May 12, and was studying star clusters in the direction of the Cancer constellation, NASA reported in late May.

“If the maneuver and download are successful, the team will begin its 19th observation campaign on August 6 with the remaining fuel,” conveyed the space agency almost four months after a previous NASA news release announced that Kepler was running out of fuel.

Not The End Of Kepler

Until then, the Kepler spacecraft is shutting down science operations and will remain parked in the “nap mode.”

“This is not ‘the end of Kepler’ by any means,” Geert Barentsen, director of the Kepler mission’s guest observer office, wrote on Twitter earlier today, noting that the Kepler data will keep astronomers busy for a long time to come.


Davenport agrees. The astronomer says that the 51 days’ worth of data currently on board the Kepler Space Telescope will be an “awesome data-set” to add to the Kepler mission if NASA can successfully get it down from space.

“The big reason the Kepler mission isn’t over is that we’ve just begun to really understand these data.”

To date, Kepler has detected 2,650 confirmed planets, to which more could be added after scientists go through this last slew of data.

Once the venerable spacecraft arrives at the end of its mission, its planet-hunting task will be taken over by NASA’s TESS (Transiting Exoplanet Survey) satellite.

As reported by the Inquisitr, TESS launched in April with the goal to survey nearly 200,000 stars by imaging up to 85 percent of the sky from a pioneering, highly elliptical orbit.