Keyhole Sat Programs:
KH8 & KH9 were film imagining.
KH11 was charge-coupled device (CCD) array technology, sent by RF transmitter.
This has been out in the open for a long time. “Deep Black” (published Dec. 1, 1988)
Not sure I still have my copy, but read it soon after it was published. Same with “The Puzzle Palace”. I loaned that to a RF tech friend of mine.