Bad news for American astronomy: The National Science Foundation has declined until 2020 to commit to any funding for either one of the two giant American-built ground-based telescopes.

For nearly a decade now, two university consortia in the United States have been in a race to build two ground-based telescopes that would be several times bigger than today’s biggest optical telescope. One group—led by the University of California—plans to build the Thirty Meter Telescope (TMT) in Hawaii. The other team—led by Carnegie Observatories, the University of Arizona, and other institutions—is developing a 28-meter behemoth named the Giant Magellan Telescope (GMT), which would be built in Chile. Over the past few years, both teams have raised tens of millions of dollars toward the billion-dollar-plus projects in the hope that the U.S. National Science Foundation (NSF) would come up with the balance.

But now, it turns out, neither project has a chance of receiving any significant funding from NSF for at least another decade. In a solicitation posted by NSF last week, the agency indicated that it does not expect to fund the building of any giant segmented mirror telescopes—that is, TMT or GMT—until the beginning of the 2020s. According to the solicitation, all that NSF can provide right now is $1.25 million over 5 years for the development of a public-private partnership plan that could eventually lead to the building of a large telescope, should NSF be in a position to fund such a telescope sometime in the next decade.

I suspect the NSF’s unwillingness to fund this project at this time is directly related to the budget crisis in Washington. Though the NSF got slightly more money in 2012 than in 2011, that money is all accounted for by other projects. There is no margin for anything new that will be as expensive (in the billions) as these giant telescopes will be.