Producing these large mirrors is a very specialized industry, the projects are extremely expensive, and the timelines are long. Things tend to get passed around between programs, sometimes for reasons as simple as a mirror having been completed after its original customer cancelled it. So it's hard to establish direct causality sometimes, especially since some of the "synergy" between projects was leveraged by the contractors to complete similar tasks without necessarily having direct interaction between the parent projects.
It's sort of like air surveillance radar. There's only a few companies that make them, the clients are civilian or military, but the economics mean that both the vendors and customers are incentivized to align the civilian and military systems as much as possible (including through shared-use agreements) in order to make the design and purchasing more economical. Thus the civilian designs are all modifications of the military designs and the military designs are all modifications of the civilian designs, they have essentially evolved in parallel.
I used to work on the MRO 2.4 meter telescope (at a small university observatory). Its main mirror was a Hubble design competition prototype that was transferred to the Air Force for intelligence use after the design wasn't selected. The Air Force kept it in storage for a long time and then provided it as part of their incentives to build the 2.4 meter with dual scientific and military applications. A lot of large mirrors used in astronomy and intelligence have stories like this. There's a number of 2.4 meter mirrors out there and pretty much all of them were made for either Hubble, KH-11, or as a shot at both.
Radio astronomy is no exception, there's a reason I bring up radar. Most radio astronomy observatories early on incorporated microwave electronics that were designed for weapons targeting radar---sometimes extremely directly, with military radar prototypes having been "looted for parts" by the astronomy commmunity after they were retired. Microwave electronics were very costly to design at the time and it saved everyone a lot of money to reuse everything.
That's really interesting information, thanks for sharing it.
And yes, the Hubble official history makes it clear that NASA intentionally sought to reuse industrial capacity and tooling developed for the NRO's surveillance satellite programme.
My point was only that the Hubble was not a donated KH-11, not that it didn't share the same industrial base as the NRO's satellites.
It's sort of like air surveillance radar. There's only a few companies that make them, the clients are civilian or military, but the economics mean that both the vendors and customers are incentivized to align the civilian and military systems as much as possible (including through shared-use agreements) in order to make the design and purchasing more economical. Thus the civilian designs are all modifications of the military designs and the military designs are all modifications of the civilian designs, they have essentially evolved in parallel.
I used to work on the MRO 2.4 meter telescope (at a small university observatory). Its main mirror was a Hubble design competition prototype that was transferred to the Air Force for intelligence use after the design wasn't selected. The Air Force kept it in storage for a long time and then provided it as part of their incentives to build the 2.4 meter with dual scientific and military applications. A lot of large mirrors used in astronomy and intelligence have stories like this. There's a number of 2.4 meter mirrors out there and pretty much all of them were made for either Hubble, KH-11, or as a shot at both.
Radio astronomy is no exception, there's a reason I bring up radar. Most radio astronomy observatories early on incorporated microwave electronics that were designed for weapons targeting radar---sometimes extremely directly, with military radar prototypes having been "looted for parts" by the astronomy commmunity after they were retired. Microwave electronics were very costly to design at the time and it saved everyone a lot of money to reuse everything.