KH-4B Corona satellite

Recovery of Discoverer 14 return capsule (typical for the Corona series

Diagram of "J-1" type stereo / panoramic reciprocating Corona reconnaissance satellite camera system used on KH-4A missions from 1963 to 1969.

Corona image of the Pentagon, 25 Sep 1967

Corona was the name of a series of US military reconnaissance satellites operated under a CIA program with substantial assistance from the US Air Force, used for photographic surveillance of the Soviet Union, China and other areas from June 1959 until May 1972. The project name is sometimes given as CORONA, but it is a codeword, not an acronym. Wikipedia does not have an article with this exact name. ... Wikipedia does not have an article with this exact name. ... Wikipedia does not have an article with this exact name. ... Wikipedia does not have an article with this exact name. ... J-1 type Corona spy satellite camera system used on KH-4A missions from 1963 to 1969. ... J-1 type Corona spy satellite camera system used on KH-4A missions from 1963 to 1969. ... Image File history File links Corona image of the Pentagon, 25 Sep 1967 Source: http://www. ... Image File history File links Corona image of the Pentagon, 25 Sep 1967 Source: http://www. ... ... A spy satellite (officially referred to as a reconnaissance satellite or recon sat) is an Earth observation satellite or communications satellite deployed for military or intelligence applications. ... The CIA Seal The Central Intelligence Agency (CIA) is one of the American foreign intelligence agencies, responsible for obtaining and analyzing information about foreign governments, corporations, and individuals, and reporting such information to the various branches of the U.S. Government. ... 1959 was a common year starting on Thursday of the Gregorian calendar. ... 1972 was a leap year that started on a Saturday. ... In telecommunication, the term code word has the following meanings: A cryptonym used to identify sensitive intelligence data. ...

The satellites were designated KH-1, KH-2, KH-3, KH-4, KH-4A and KH-4B. KH stood for Keyhole, and the incrementing number indicated changes in the surveillance instrumentation, such as the change from single-panoramic to double-panoramic cameras. The KH naming system was first used in 1962 with KH-4 and the earlier numbers were retroactively applied. There were 144 Corona satellites launched, of which 102 returned usable imagery. The term panoramic format is used to refer to high aspect ratio or wide screen image format. ... A camera is a device used to take pictures (usually photographs), either singly or in sequence, with or without sound, such as with video cameras. ... 1962 was a common year starting on Monday (link will take you to calendar). ...

The Corona satellites used 31,500 ft (9,600 m) of special 70 mm film with a 24 inch (0.6 m) focal length lens. Initially orbiting at 165 to 460 km, the cameras could resolve images on the ground down to 7.5 m. The two KH-4 systems improved the resolution to 2.75 m and 1.8 m respectively and used a lower altitude pass. A foot (plural: feet) is a non-SI unit of distance or length, measuring around a third of a metre. ... The metre, or meter, is the basic unit of length in the International System of Units (SI: Système International dUnités). ... Film refers to the celluloid media on which movies are printed Film is a term that encompasses motion pictures as individual projects, as well as the field in general. ... The focal point F and focal length f of a positive lens, a negative lens, a concave mirror, and a convex mirror. ... A lens is a device for either concentrating or diverging light, usually formed from a piece of shaped glass. ... Altitude is the elevation of an object from a known level or datum, called zero level. ...

Ironically, the name Corona was more fitting than its originators had ever imagined. The initial missions of the program suffered from many technical problems, among them, mysterious fogging and bright streaks were seen on the returned film of some missions, only to disappear on the next mission. Eventually it was determined by a collaborative team of scientists and engineers from the project and from academia, (among them: Luis Alvarez, Malvin Ruderman, and Sidney Drell) that electrostatic discharges (called corona discharge) caused by rubber components of the camera, were exposing the film. Recommended corrective actions solving the problem included better grounding of spacecraft components and outgassing testing of parts before launch. These practices are still used on practically all US reconnaissance satellites today. Luis Walter Alvarez (June 13, 1911 – September 1, 1988) of San Francisco, California, USA, was a famed physicist who worked at the University of California, Berkeley. ... In electricity, a corona discharge is an electrical discharge brought on by the ionization of a fluid surrounding a conductor, which occurs when the potential gradient exceeds a certain value, in situations where sparking is not favoured. ...

The initial Corona launches were obscured as part a space technology program called Discoverer, the first test launches for which were in early 1959. The first launch with a camera was June 1959 as Discoverer 4, which was a 750 kg satellite launched by a Thor-Agena rocket. The key issue with the early satellites was the recovery of the exposed film. Radio link technology did not exist, and so film canisters were returned to Earth in capsules, called "buckets", which were recovered in mid-air by a specially equipped aircraft during their parachute descent. The first camera-fitted Discoverer missions failed to return usable film, but following repeated recovery tests on August 18, 1960 with Discoverer 14, a bucket was successfully retrieved two days later by a C-119. Thor-Ablestar Thor was the United Statess first operational ballistic missile. ... For the Agena star, see Hadar. ... A helicopter with a long hook can catch a parachuting object in mid-air, as seen here in a practice run for the planned retrieval of Genesis. ... August 18 is the 230th day of the year (231st in leap years) in the Gregorian calendar. ... 1960 was a leap year starting on Friday (link will take you to calendar). ... The C-119 was a U.S. military transport aircraft developed from the World War II Fairchild C-82 Packet, designed to carry cargo, personnel, litter patients, and mechanized equipment, and to drop cargo and troops by parachute. ...

Discoverer 13 was the first satellite that landed and was recovered on August 11, 1960. August 11 is the 223rd day of the year (224th in leap years) in the Gregorian Calendar. ... 1960 was a leap year starting on Friday (link will take you to calendar). ...

The last launch under the Discoverer name was Discoverer 38 in 1962; after that the launches were entirely secret. The last Corona launch was on May 25, 1972. The best sequence of Corona launches was from 1966 to 1971 when there were 32 consecutive launch-and-film-recoveries. A typiclal classified document. ... May 25 is the 145th day of the year in the Gregorian calendar (146th in leap years). ... 1972 was a leap year that started on a Saturday. ... 1966 was a common year starting on Saturday (link goes to calendar) // Events January January 1 - In a coup, Colonel Jean-Bédel Bokassa ousts president David Dacko and takes over the Central African Republic. ... 1971 is a common year starting on Friday (click for link to calendar). ...

Corona was officially secret until 1992. On February 22, 1995 an Executive Order declassified the imagery acquired by the Corona and two later programs (Argon and Lanyard). 1992 is a leap year starting on Wednesday of the Gregorian calendar. ... February 22 is the 53rd day of every year in the Gregorian Calendar. ... 1995 was a common year starting on Sunday of the Gregorian calendar. ... An executive order is an edict issued by a member of the executive branch of a government, usually the head of that branch. ... Codenamed Argon, the KH-5 was a series of reconnaissance satellites produced by the United States from February 1961 to August 1964. ... Codenamed Lanyard, the KH-6 was a shortlived series of reconnaissance satellites produced by the United States from March to July 1963. ...

References

• Dwayne A. Day, John M. Logsdon, and Brian Latell (Eds.), Eye in the Sky: The Story of the Corona Spy Satellites. Washington, DC: Smithsonian Books. ISBN 1560987731 (paperback) or ISBN 1560988304 (hardcover).

• Curtis Peebles, The Corona Project: America's First Spy Satellites. Annapolis: Naval Institute Press. ISBN 1557506884.

External links

• US Geological Survey overview and image search
• Corona page at NASA
• Corona page at NRO
• GlobalSecurity.org: Imagery Intelligence