Meeting the Challenge: The Hexagon KH-9 Reconnaissance Satellite is the recently declassified story of the design, development, production, and operation of the Hexagon KH-9 reconnaissance satellite, which provided invaluable photographic intelligence to the U.S. government, and stands as one of the most complicated systems ever put into space. Former Perkin-Elmer engineer Phil Pressel has written the definitive account of this important chapter in U.S. intelligence and aerospace history, featuring both technical details and historical anecdotes. Developed by the Perkin-Elmer Corporation, and operated between 1971 and 1986, Hexagon was the last film-based orbiting photoreconnaissance satellite. The Hexagon project yielded many important achievements: stereo photography of the entire surface of the Earth; ability to precisely control the synchronization of film traveling at up to 200 inches per second at the focal plane, on a rotating camera in a moving vehicle while focused on the rotating Earth; exposure of sixty miles of film on each mission; development and use of new and sophisticated electronics, such as LEDs and brushless motors; and use of the world's largest spherical thermal vacuum chamber to test the system. Visit Phil Pressel’s blog at https://www.hexagonkh9.com.