America's Great Observatories – The Hubble, Chandra, Compton and Spitzer space telescopes – have peered into the unknown and made breakthrough discoveries about newborn stars, dark matter and the age of the universe.
These telescopes, whose era began in 1990, are aging, if not dead, and there is no budget or political will to replace them.
This sobering reality was underscored this month when two were beset by technical problems, including the Hubble Space Telescope, that temporarily stopped their science.
The astronomers want to lose some of their key eyes in the skies before NASA can launch new telescopes. It wants to make some research impossible.
"The unwillingness to invest in substantial science has begun," said astrophysicist Matt Mountain, president of the Association for Research on Astronomy, which operates the Hubble telescope on behalf of NASA. "We are facing a very daunting prospect as a community. Some fields just do not have a telescope. And the science does not want to do any other way. "
Some of science's biggest questions – What is dark energy? Does life exist beyond the solar system? Can only be answered by large observatories working in particular parts of the light spectrum.
Whether to invest in pursuing these questions is a choice for the nation, said Paul Hertz, the astrophysics division director at NASA.
The system prioritized the Great Observatories program when it was conceived in the 1970s and 80s – four telescope missions to cover the light spectrum in space. They launched between 1990 and 2003.
There is the Compton Gamma Ray Observatory for capturing the most energetic explosions in the universe. The Spitzer Space Telescope to seek out of exoplanets and newborn stars. The Chandra X-ray Observatory could test the depths of black holes and uncovered evidence for dark matter and dark energy.
The Hubble Space Telescope is the program's crown jewel, with its massive dish for light harvesting in the ultraviolet and visible wavelengths known as the age of the universe, at the centers of galaxies, and photographed the most distant objects seen.
Space telescopes are difficult to engineer and expensive to build. But they are necessary to clear a glimpse into the cosmos. Even at night, Earth's atmosphere distorts light from space, making images blurry and other signals – especially gamma rays – impossible to see.
Using the fleet in concert enhances these telescopes' power even further. Last year, observations by Hubble, Chandra, Fermi and other astronomers to confirm theories about fundamental physics.
They may not always have that ability.
The compton telescope was lost in 2001, when a problem with its gyroscope – which allows a telescope to rotate and point at something – meant the space agency had intentionally ground it or risk the spacecraft plummeting uncontrolled out of the sky.
Spitzer, which has been slowly drifting away from Earth, wants to finish its mission when it loses contact sometime next year. Hubble and Chandra this month were un-anticipated one-two punch.
Neither of the spacecraft's problems are fatal, NASA said. Chandra came back online after a glitch with one of her gyroscopes.
Hubble, which was lifted by another gyroscope difficulty, is expected to return to normal surgery within a few weeks at the most. NASA expects both telescopes to continue into the 2020s.
Still, the letter brush with oblivion gave astronomers a lasting scare.
"Hubble is not going to live forever," said Tom Brown, the Hubble mission head at the Space Telescope Science Institute.
Chandra is 19 years old; Hubble is 28.
Brown said the frantic fellow astronomers have kept ringing his phone "non-stop" in the past two weeks.
NASA's billion-dollar-a-year astrophysics program has eight major telescopes aimed at studying space beyond the solar system. – the bonus years beyond the time for which the spacecraft originally designed.
The only flagship NASA space observatory under construction is the James Webb Space Telescope, whose gold-plated dish is designed to collect radiation from the earliest objects in the universe.
NASA intended for the timing of Webb's mission to overlap significantly with Hubble's. The launch of the $ 10 billion behemoth has also been delayed as the space deals with design issues and costly human errors. This year, NASA announced that Webb will not launch until 2021 at the earliest, cutting the concerted observing time short.
NASA's next big project would be the Wide Field Infrared Survey Telescope, which is also targeted for infrared wavelengths and in 2010 was considered the top astrophysics priority of the National Academy of Sciences. Funding for the Observatory has been dropped in the air after President Trump omitted.
The outlook for research across the spectrum are fuzzy at best. When Hubble fails, Brown pointed out, there is no visible or ultraviolet telescope at that scale.