The first space telescopes: five-minute rockets, the $100 bolt, 23,000 UV readings
Before the Hubble, before James Webb, NASA engineers in the 1960s were trying to figure out how to keep a giant camera perfectly still in space to capture light the human eye could never see. Hey, I'm Salt. I'm Grace. So this is basically where space telescopes began, right? We think of Hubble as the pioneer, but you're taking us back to the Apollo era.
Yeah, the mid-1960s. And the problem they were trying to solve was ultraviolet light. According to the University of Chicago's multi-wavelength archives, Earth's atmosphere absorbs pretty much all UV light with wavelengths shorter than 3,800 angstroms. Which is, you know, good for our skin, but bad for astronomy. Exactly.
Ground telescopes are fundamentally blind to it. The atmosphere just — Salt, if you want to see the universe's highest-energy, most violent stuff, you have to get above the atmosphere. Okay, how were they doing that before they could put a permanent observatory up there? Sounding rockets. They'd shoot a rocket straight up, uh, it would poke above the atmosphere, and NASA's historical logs show astronomers would get about five minutes of UV observation time before the rocket fell back to Earth.
Five minutes? You can't build a map of the sky in five-minute chunks. Right, and they proved that. By 1968, they had launched 40 of those rockets, and all of them combined yielded just three total hours of data. That can't be right.
Three hours from 40 launches. They needed a satellite. And the person who pushed that through was Dr. Nancy Grace Roman. She was hired by NASA in 1959 as its first Chief of Astronomy.
I know they named the new telescope after her, but what was her role back then? She basically built NASA's space astronomy program, uh, from the ground up. The American Association of University Women notes she was — she was the agency's first female executive, and she spent years traveling around the country, um, convincing a very skeptical, very male-dominated astronomy establishment that putting telescopes in space wasn't just a fantasy. Did they believe her? Not at first.
A lot of astronomers argued the money should go to ground telescopes. But Roman pushed through that and got them to fund — she secured the funding for the Orbiting Astronomical Observatory program, or OAO. So when does the first OAO reach orbit, Grace? April 8, 1966. OAO-1 goes up, and it's this huge, intricate machine, but the — but the star trackers suffer severe high-voltage arcing, and then the main battery breaks down, so just three days into the mission, the whole spacecraft goes dead.
Wait — what? Three days. It didn't send back a single piece of scientific data. That's brutal. How did NASA handle losing the mission in three days?
It almost derailed the astronomy program. But instead, NASA's post-flight reports show they used the failure to rewrite their testing procedures. They realized they had to test the whole assembled spacecraft in a thermal vacuum chamber that simulated space, you know, rather than just checking the parts one by one. Did the new testing fix the issues for the next one? It did.
OAO-2 launched on December 7, 1968, and it was a triumph. NASA's 50th-anniversary retrospective on the mission notes that it operated until January 1973, and it completed nearly 23,000 stellar UV measurements. Wow. From three hours of data to 23,000 measurements is a real leap. It really was.
But the danger wasn't gone. In 1970, they launched OAO-B, which carried the most sensitive telescope yet, and the — the rocket fairing failed to detach because of a single explosive bolt that cost about $100, which dragged the whole observatory right back into the atmosphere to burn up. You're kidding. I wish I was. It just highlights how unforgiving early space flight could be.
You could spend years designing this incredible scientific instrument, and one stuck bolt drops it in the ocean. So the program survived that, right? Because they launched a third one? They did. OAO-3 went up in 1972, and it worked beautifully.
It proved that you could achieve precise three-axis stabilization in orbit, which kind of rewrote our understanding of stellar temperatures and laid the groundwork for Hubble. So without Nancy Grace Roman and those early failures, we sort of don't get modern space astronomy. Or the Roman Space Telescope, which is the next flagship NASA is preparing to launch. We're left to wonder how much of modern astrophysics we owe to those 1960s engineers who just refused to let early orbital disasters ground their dreams. Thanks a lot for listening to Daybrain.
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