An old friend posted this on linkedin:
http://www.theatlantic.com/technology/archive/2011/12/top-secret-your-briefing-on-the-cias-cold-war-spy-satellite-big-bird/250629/
It's incredible to think that spy satellites were operating in the 70s, before any sort of digital technology, and dropping the exposed film to earth to be picked up by hercs.
"The amazing story of how our supersecret, Cold-War spy satellites took photos of the Soviet empire and dropped them to Earth, all without the help of computers, bandwidth, or digital cameras."