U.S. Hexagon KH9 reconnaissance satellites were designed for wide area search and were the last U.S film based satellites. Declassified in 2011, the clever and complex opticalmechanical systems brought film back to earth for military and intelligence services during the cold war. This provided the U.S. with very good intelligence on adversaries and other areas of strategic interest.
On loan from the National Reconnaissance Office, one can be seen at the National museum of the Air Force in Dayton, Ohio.
https://www.nationalmuseum.af.mil/Vis...
Phil Pressel’s is a former employee on the design of the Optical Bar system. His blog is a pleasure to read:
https://www.hexagonkh9.com/