In the early 1930s, Bell Labs was experimenting with making wireless transatlantic calls. The communications goliath wanted to understand the static that might crackle across the ocean, so it asked an engineer named Karl Jansky to investigate its sources. He found three: nearby thunderstorms, distant thunderstorms, and a steady hiss, coming from … somewhere.

Jansky studied the hiss for a year, using a rudimentary antenna that looked like toppled scaffolding, before announcing its origin: The static was coming from the the galaxy itself. "Radio waves heard from remote space," announced The New York Times in May 1933. "Sound like steam from a radiator after traveling 30,000 light-years." Janksy had unwittingly spawned the field of radio astronomy.

Today, a replica of Jansky's scope sits on the lawn in front of Green Bank Observatory, one of the four world-class public radio telescopes in the US. Along with the Very Large Array, Arecibo Observatory, and the Very Long Baseline Array (VLBA), it is the legacy of a boom time in federal investment in the field that began in earnest after World War II.

In the past several years, though, the National Science Foundation has backed away from three of those instruments. In 2012 the NSF published a review recommending that the foundation ramp down funding to Green Bank—just 11 years after it was finished—as well as the VLBA, which can resolve a penny from about 960 miles away. Three years later, the foundation asked Arecibo for management proposals that "involve a substantially reduced funding commitment from NSF.”

Now, the future of those scopes—instruments that map the gaseous threads that connect cosmic neighborhoods, penetrate the dust shrouds surrounding not-yet stars, and probe way-warped spacetime—is in question. “Radio astronomy is really, really unique in the kinds of astrophysics that we can study,” says Brian Kent, an astronomer at the National Radio Astronomy Observatory.

That work is far from stopping. But support for pure science in the US is always complicated, since it relies on the good graces of federal agencies and annual budgets. As funders balance building and operating new scopes with the old, while giving grants to the astronomers who actually use those instruments, something's gotta give. And no matter what it is, the science will not be the same.

Building massive radio telescopes—which today cost anywhere from around $100 million to more than $1 billion—actually began as a cost-sharing measure. In the 1950s, the nascent radio astronomy community realized universities couldn't afford to build their own scopes—at least not ones of high enough quality to drive the field forward. So in 1956, the United States formed the National Radio Astronomy Observatory, building a succession of telescopes in Green Bank that it could loan out to scientists from around the country. In Puerto Rico, construction on the 300-meter Arecibo observatory began in the 1960s, and it became the National Astronomy and Ionosphere Center. In the 1970s, the NRAO started building the Very Large Array in New Mexico.

Most recently, NRAO helped create the Atacama Large Millimeter/Submillimeter Array, or ALMA, in Chile. It cost more than a billion dollars to build, with the NSF contributing around $500 million, and another approximately $40 million per year to operate it. But it's worth it: In US astronomy, interferometers, or telescopes like ALMA made of many smaller antennas, are currently more popular with scientists than big single-dish scopes, says NSF astronomy division director Richard Green. “We really try to be responsive to community interest,” he says. Interferometers provide higher resolution—crisper pictures of smaller areas—and can investigate many of the same celestial phenomena.