Part of our comprehensive series on the National Reconnaissance Office (NRO) and its "spy satellite" network, this volume covers the Gambit photoreconnaissance satellite flown between 1963 and 1984. The previously classified documents in this collection were released by the NRO in September 2011 as part of its 50th anniversary. In declassifying these fascinating documents, the NRO has opened the curtain to show the tremendous challenges that were overcome to achieve the impressive successes that help win the Cold War. CORONA was the first successful program in applying space vehicles to overflight reconnaissance operations. In its several evolutionary versions, CORONA steadily improved its photographic surveys of denied areas (with final resolutions of six to ten feet), operating in what the Intelligence Community calls "search mode." GAMBIT was developed to perform at even better resolutions than CORONA and work against specified targets-an operation usually referred to as "surveillance mode." GAMBIT fulfilled this surveillance function from July 1963 to April 1984. Although Corona provided the capability to search large areas from space, the U.S. still lacked high resolution imagery. Approximately one year after the first launch of Corona, the National Reconnaissance Office began development of its first high resolution satellite program, codenamed Gambit. Over time, the Gambit program evolved into two different systems. The first Gambit system, launched in 1963, was equipped with the KH-7 camera system that included a 77-inch focal length camera for providing specific information on scientific and technical capabilities that threatened the nation. Intelligence users often characterized this capability as surveillance, allowing the United States to track the advancement of Soviet and others' capabilities. The second system, Gambit 3 was equipped with the KH-8 camera system that included a 175-inch focal length camera. The system was first launched in 1966 and prov