CORONA (satellite)
The CORONA[1] program was a series of American strategic reconnaissance satellites produced and operated by the Central Intelligence Agency (CIA) Directorate of Science & Technology with substantial assistance from the U.S. Air Force.
The CORONA satellites were used for photographic surveillance of the Soviet Union (USSR), China, and other areas beginning in June 1959 and ending in May 1972.
[3] CORONA started under the name "Discoverer" as part of the WS-117L satellite reconnaissance and protection program of the U.S. Air Force in 1956.
[4] The primary goal of the program was to develop a film-return photographic satellite to replace the U-2 spyplane in surveilling the Sino-Soviet Bloc, determining the disposition and speed of production of Soviet missiles and long-range bombers assets.
[6] CORONA ultimately encompassed eight separate but overlapping series of satellites (dubbed "Keyhole" or KH[7]), launched from 1959 to 1972.
With the success of Discoverer 14, which returned 16 lb (7.3 kg) of film and provided more coverage of the Soviet Union than all preceding U2 flights, for the first time the United States had a clear picture of the USSR's strategic nuclear capabilities.
[8]: 38–39 Additionally, CORONA increased the pace at which intelligence could be received, with satellites providing monthly coverage from the start.
Photographs were more easily assessed by analysts and political leaders than covert agent reports, improving not just the amount of intelligence but its accessibility.
[8]: 38–39 The KH-1 series ended with Discoverer 15 (13 September 1960), whose capsule successfully deorbited but sank into the Pacific Ocean and was not recovered.
[20] In 1963, the KH-4 system was introduced with dual cameras and the program made completely secret by then president, John Kennedy.
Because of the increased satellite mass, the basic Thor-Agena vehicle’s capabilities were augmented by the addition of three Castor solid-fueled strap-on motors.
On 28 February 1963, the first Thrust Augmented Thor lifted from Vandenberg Air Force Base at Launch Complex 75 carrying the first KH-4 satellite.
Eventually the dead weight of the strap-on motor dragged the Thor off its flight path, leading to a Range Safety destruct.
The new maneuvering rockets were designed to boost CORONA into a higher orbit, and lengthen the mission time even if low perigees were used.
[23] For use during unexpected crises, the National Reconnaissance Office (NRO) kept a CORONA in "R-7" status, meaning ready for launch in seven days.
Although the best resolution was only obtained in the center of the image, this could be overcome by having the camera sweep automatically ("reciprocate") back and forth across 70° of arc.
[44] The drum permitted the use of up to two filters and as many as four different exposure slits, greatly improving the variability of images that CORONA could take.
[citation needed] The initial CORONA missions suffered from mysterious border fogging and bright streaks which appeared irregularly on the returned film.
Eventually, a team of scientists and engineers from the project and from academia (among them Luis Alvarez, Sidney Beldner, Malvin Ruderman, Arthur Glines,[47] and Sidney Drell) determined that electrostatic discharges (called corona discharges) caused by some of the components of the cameras were exposing the film.
If none was found or the corona observed was within acceptable levels, the canisters were certified for use and loaded with fresh film for a launch mission.
The targets consisted of concrete arrows located in and to the south of the city, and may have helped to calibrate the cameras of the satellites.
[55] The capsule was intended to be caught in mid-air by a passing airplane[56] towing an airborne claw which would then winch it aboard, or it could land at sea.
[57] A salt plug in the base would dissolve after two days, allowing the capsule to sink if it was not picked up by the United States Navy.
[58] After Reuters reported on a reentry vehicle's accidental landing and discovery by Venezuelan farmers in mid-1964, capsules were no longer labeled "SECRET" but offered a reward in eight languages for aerial footage return to the United States.
[35] Beginning in 1963, another improvement was "Lifeboat", a battery-powered system that allowed for ejection and recovery of the capsule in case power failed.
[65] The procurement and maintenance of the CORONA satellites were managed by the Central Intelligence Agency (CIA), which used cover arrangements lasting from April 1958 to 1969 to get access to the Palo Alto plant of the Hiller Helicopter Corporation for the production.
[66] At this facility, the rocket's second stage Agena, the cameras, film cassettes, and re-entry capsule were assembled and tested before shipment to Vandenberg Air Force Base.
For their role in creating the first space-based Earth photographic observation systems, they were awarded the Charles Stark Draper Prize in 2005.
On 22 February 1995, the photos taken by the CORONA satellites, and also by two contemporary programs (ARGON and KH-6 LANYARD) were declassified under an Executive Order signed by President Bill Clinton.
[73] The declassified imagery has since been used by a team of scientists from the Australian National University to locate and explore ancient habitation sites, pottery factories, megalithic tombs, and Palaeolithic archaeological remains in northern Syria.
