KH-9 Hexagon

The KH-9 Hexagon, nicknamed Big Bird, was the last and most elaborate of the American film-return photographic reconnaissance satellites. Twenty were launched on Titan III boosters by the National Reconnaissance Office between 1971 and 1986, and all but the final one reached orbit. It was a broad-area search system meant to replace the Corona series: two panoramic cameras photographed in stereo, and exposed film came home in up to five recoverable reentry capsules that were caught in mid-air or recovered from the sea. Lockheed Missiles and Space Company held the contract for the satellite basic assembly, Perkin-Elmer built the main camera and McDonnell the reentry vehicles. Later missions carried a mapping camera, and the satellite grew heavier through four design blocks until each mission lasted up to 275 days. The program was declassified in 2011.