The alien planet-hunting space probe was powered down into hibernation mode in a bid to transmit Kepler’s last set of observations to Earth.
Earlier last week NASA’s Kepler team was informed the space telescope’s fuel tanks were running very low.
Powering Kepler down will help the US astronomers salvage and download as much data as possible.
Once the stellar observations are collected, NASA will power up the telescope to continue observing deep space with whatever fuel is left.
In a statement, NASA said: “To bring the data home, the spacecraft must point its large antenna back to Earth and transmit the data during its allotted Deep Space Network time, which is scheduled in early August.
“Until then, the spacecraft will remain stable and parked in a no-fuel-use safe mode.
“On August 2, the team will command the spacecraft to awaken from its no-fuel-use state and manoeuvre the spacecraft to the correct orientation and downlink the data.”
If successful, NASA will initiate Kepler’s 19th and potentially final observation of space.
NASA expects Kepler to completely run out of fuel within the next few months.
In March 2018, NASA said: “It’s like trying to decide when to gas up your car. Do you stop now? Or try to make it to the next station?
“In our case, there is no next station, so we want to stop collecting data while we’re still comfortable that we can aim the spacecraft to bring it back to Earth.”
The dire NASA news is particularly hard-hitting due to Kepler’s incredible contribution to the discovery of alien planets outside of our solar system.
About 70 percent of the 3,750 so-far observed exoplanets were discovered by the £425million ($600million) space mission laughed in March 2009.
Within the first few months of Kepler’s mission the telescope discovered about 7,500 star candidates housing alien worlds.
The Kepler space probe discovers alien planets by scanning the stars for tiny drops in brightness when a potential planet passes in front of them.
The so-called transit method has been incredibly successful in confirming more than 2,500 exoplanets with an additional 2,700 potential exoplanets on the waiting list.
Astronomer James Davenport, praised Kepler’s contributions to science after the news broke.
He said: “For a long time now we’ve known the spacecraft is running out of gas.
“When I went to the Kepler Science Conference at NASA Ames in the Bay Area last year, someone said the Kepler spacecraft had less than two pints of fuel left.
“Well now we’ve gone down to fumes which is basically nothing.
“Optimistically I thought we would have run out of gas sometime at the beginning of Campaign 16 – that is when we did the ‘wave at Earth image’.
“Not only did Kepler, or K2 as they are calling it now, make it through Campaign 16 but it also made it through Campaign 17 and 51 days into Campaign 18. That’s way more than I expected.”
The Kepler space mission has been operating for more than nine years and the telescope is nearly 100 million miles away from the planet.
Because the spacecraft is not even remotely close to Earth, Kepler will forever remain trapped in space once its engines finally go cold.