Hubble wasn't but a pair of Key Hole satellites (KH-11) were.

https://www.americaspace.com/2012/06/06/top-secret-kh-11-spy...

Hubble was built by the same contractors that build the Keyhole satellites. They whole idea from the beginning was to reuse the spy satellite hardware for astronomy.

Almost everything is reusable between these applications, just need a flatter mirror. Which was also what they screwed up.

But we followed the making of hubble long before it launched. Why would anyone believe such a silly rumor when the development of the telescope was in the open?

What makes it a rumor? In the video Scott states that the “cost saving measure” of reducing the target mirror diameter down to 2.4m was to use the same manufacturing as these exact spy satellites.

Do you not understand that if a top secret spy satellite is gifted to astronomers, a cover story - i.e. a lie - will be made up about how it is developed by brilliant civilians?

I understand you believe that but I don’t have to believe it myself and that kind of condescending tone isn’t really necessary here, especially defending a conspiracy theory. The existing publicized NRO grants, including the keyhole satellites mentioned elsewhere in the thread, suggest the simpler answer is more accurate. The Hubble development was heavily publicized through its lifecycle, including the repair after it was deployed. Why bother with such a performance when next time the NRO donates a satellite they publish about it for the PR?

Likewise it should be understood that the more complicated the coverup and the more detailed the lies, the more likely that cover story is to fall apart.

Given the cooperation with the ESA and with the difficulties in grinding the main mirror, I find it far less likely that it was a platform gifted to NASA by an intelligence agency.

You would need thousands of civilians to take part in your life then. Not easy.

Annoyed? Sure. Surprised? Only the naive would be.

If there was a 3-5m spy satellite I wouldn't be surprised, but if there was a 20-30m spy satellite (I.e. a project likely larger in scale and complexity than the ISS) then I'd be surprised.