Did such things actually exist then? Gathering useful info and transmitting it to the ground? Or could it be a spy satellite?
Apparently, they were astronomical observatories. Not for the visible spectrum, but rather UV and X-ray. There were 4 launched, but only 2 were successful.
Yes, they did. Check out this Wikipedia list.
The publicized ones which orbited by the early '60s were primarily studying the upper atmosphere, the Earth’s magnetic field, cosmic radiation, etc. And, by then there were also weather satellites.
I have become so cynical over the years. I assume that those were actually spy satellites. My brother -in -law spent his year in Vietnam flying in an air force “weather plane” over the South China sea & Tonkin gulf area. 10 % of the plane was weather - related,..90% of the plane was listening and studying North Vietnamese radar signals . As those old vets used to say..“There it is”
The US Corona spy satellite program started life in 1959, and by 1964 was fully operational with the KH-4 satellites.
An X-ray observatory would be useless for spying, for the same reason that it’s necessary to put a real X-ray observatory in orbit: Despite us thinking of X-rays as especially penetrating, and the atmosphere being completely clear, air is actually opaque to X-rays.
We also had spy satellites, of course. But I don’t think they were ever disguised as astronomical missions. It’d be a lousy cover for a spy satellite, since it would leave the astronomers wondering why they’re not getting any of the astronomical data.
If you go to 1967, satellites looking for covert nuclear tests via x-ray and gamma rays discovered gamma-ray bursts Gamma-ray burst - Wikipedia