Kepler, NASA’s designated planet-hunter, could be in trouble.

Bill Borucki, the spacecraft mission’s longtime head, told Alexis Madrigal at the Atlantic that he was getting nervous about funding as Kepler heads toward the end of its initial 3.5 year life span.

“There is a serious worry that Kepler's funding might not be extended,” Borucki said.

An artist's concept of Kepler-10b, a rocky planet measuring 1.4 times the size of Earth discovered by NASA's Kepler mission. Kepler-10b was the smallest planet discovered outside our solar system and the first star identified as able to harbor a small transiting planet. (AFP/Getty Images)

The late astronomer Carl Sagan. (EDUARDO CASTANEDA/AP)

But Kepler costs $20 million a year.

While Madrigal points out tha $20 million is the “cost of fighting a few hours of the war in Afghanistan,” these are belt-tightening times, and influential supporters such as astronomer Carl Sagan, who died in 1996, are no longer around.

(Sagan, the American astronomer, author, TV host and pioneer of exobiology and the Search for Extra-Terrestrial Intelligence, would likely roll over in his grave if he thought the government would stop funding the search for other planets.)

The Kepler spacecraft has so far discovered hundreds of planetary candidates by watching 145,000 stars for variations in their brightness, which can help flag the presence of an extrasolar planet.

On Tuesday, BBC reported that two new exoplanets were spotted by amateur stargazers who analyzed images generated by Kepler last year.

Scientists now say it’s highly likely there are other Earths out there. But if Kepler goes, we may never know about them.

“It will be one of those small bureaucratic losses that hardly anyone notices,” Madrigal writes. “But it will be yet another sign of the fraying of our democracy that we can't fund (cheap) research into the most fundamental questions of human existence.”