I assume the NRO telescopes had their instrumentation removed before gifting the optics to NASA, yes? Or were they really just "blank casings"? Either way, it's kinda freaky to think that there are such powerful monitoring devices in space...
Since they were never launched, and (according to NASA) the satellite itself is the part that takes the longest to build, it's plausible that the instrumentation was never installed before the mission was scrapped for whatever reason.
100+ meter diameter radio telescopes pointed at the earth. That's the same size as the largest steerable ground-based radio telescopes. Makes you wonder what they can hear.
