I wrote HERE last week that the secretive National Reconnaissance Office, or NRO, was going to put on public display last Saturday for the first time some of its top secret spy satellites. They did and you can read about it HERE (including a photo of the most famous one displayed, the so-called "Big Bird" HEXAGON satellite).
I thought that these few sentences sandwiched in the middle of this long story were the most intriguing, however.
"According to documents released by the NRO, each HEXAGON satellite mission lasted about 124 days, with the satellite launching four film return capsules that could send its photos back to Earth. An aircraft would catch the return capsule in mid-air by snagging its parachute following the canister's re-entry. In a fascinating footnote, the film bucket from the first KH-9 HEXAGON sank to the bottom of the Pacific Ocean in spring 1972 after Air Force recovery aircraft failed to snag the bucket's parachute. The film inside the protective bucket reported contained high resolution photographs of the Soviet Union's submarine bases and missile silos. In a daredevil feat of clandestine ingenuity, the U.S. Navy's Deep Submergence Vehicle Trieste II succeeded in grasping the bucket from a depth of 3 miles below the ocean."