December 1953: U.S. Air Force, which had been split off from the Army in 1947, pulls together all its various satellite efforts into a single program known as WS-117L.
October 1956: Lockheed Air craft Corp. gets the first WS 117L production contract.
Feb. 28, 1958: The Defense Department officially cancels the reconnaissance-satellite segment of WS-117L in an effort to plug security leaks. The project, now carrying the name “Corona,” undergoes what the Central Intelligence Agency calls “covert reactivation”Â¥ only a small number of government officials, Lockheed employees and employees at other defense contracting companies are briefed on the new effort.
Jan. 21, 1959: The first attempt to launch a rocket designed to carry the Corona satellite, assembled at the Hiller Aircraft plant in Menlo Park, ends in failure 60 minutes before blast off at Vandenberg Air Force Base near Santa Barbara when explosive bolts are triggered accidentally, damaging the rocket.
Feb. 28,1959: Discoverer 1, the cover name for Corona rock ets, lifts off from Vandenberg and disappears. No one knows what happened, but it is believed to have crashed some where near the South Pole.
April 13, 1959: Discoverer ll goes into orbit and successful ly ejecSs a test capsule. But, because of a timing error, the capsule lands somewhere on the island of Spitsbergen, north of Norway, instead of hitting its target near Hawaii. The capsule is never found; CIA officials suspect it may have been snatched by the Soviets.
June 3: Discoverer lll, carrying four mice, crashes in the Pacific Ocean shortly after takeoff.
June 25: Discoverer IV carries the first Corona camera, caned. KH-1, an abbreviation of the code name Keyhole. The rock, et fails to reach orbit. Three more launches in August and November also are busts.
Aug. 10: Discoverer Xlll is a partlal successÂ¥the satellite successfully reaches orbit and ejects a capsule, carrying an American Hag and test equipment. The capsule lands north of Hawaii the next day, 600 miles off target, and is recovered after floating in the ocean.
Aug. 19: With almost no public fanfare, Discoverer XIV is the first truly successful Corona mission. The retuming capsule, containing 20 pounds of film and suspended from a parachute, is snatched from midair by an Air Force C-119 aircraft. The images, although fuzzier than U-2 photographs, cover areas of the Soviet Union nev er reached by the spy planes.
Dec. 10: Discoverer XVIII is the second truly successful mission, returning 39 pounds of film filled with images from an improved camera, the KH-2.
Aug. 30, 1961: Corona up grades to the-KH-3 camera, doubling the Ibvel of detail.
Feb. 27, 1962: The last launch in the Discoverer series, Discoverer XXXVIII, is a successful debut mission for the new KH 4 camera. The Air Force now imposes a total security blanket on Corona, future launches will be secret, with no effort to maintain a cover story of scientific research.
1966: Corona reaches its prime. From May 1966 through February 1971, 32 launches in a row are either partially or completely successful.
June 15, 1971: A new generation spy satellite called “Hexagon” is launched from Vandenberg. It carries a KH-9 camera, capable of exposing more film and covering a wider area on the ground.
May 25, 1972: The final Corona mission is launched, with the fi nal capsule recovered on May 31. During the life of the pro gram, Corona mapped 750 mil lion square miles of the Earth’s surface, mostly ih the Soviet Union and China; the resolution of its cameras improved from initially distinguishing objects on the ground no smaller than 20 feet to picking out objects just five feet across.
Feb. 22, 1995: President Clinton signs an executive officer declassifying Corona, the first time the United States has released a significant amount of information about its spy satellite programs