Big Bird (satellite)

KH-9, codenamed HEXAGON, and popularly known as Big Bird,cite book|author=Yenne, Bill|title="The Encyclopedia of US Spacecraft"|publisher=Exeter Books (A Bison Book), New York|year=1985|id=ISBN 0-671-07580-2p.32 Big Bird] was a series of photographic reconnaissance satellites launched by the United States between 1971 and 1986. Of twenty launch attempts by the United States Air Force, all but one were successful. Camera film canisters aboard Big Bird was sent back to earth in a recoverable 'film return' capsules for processing and interpretation.

Officially known as the Broad Coverage Photo Reconnaissance satellites (Code 467), built by Lockheed Corporation for the US Air Force.

Development

The KH-9 was originally conceived in the early 1960s as a replacement for the Corona search satellites. The goal was to search large areas of the earth with a medium resolution camera. The KH-9 carried two main cameras, although a mapping camera was also carried on several missions. The photographic film from the cameras was sent to recoverable re-entry vehicles and returned to earth, where the capsules were caught in mid-air by an aircraft. Four re-entry vehicles were carried on most missions, with a fifth added for missions that included a mapping camera.

Over the duration of the program the lifetime of the individual satellites increased steadily. The final KH-9 operated for up to 275 days. Different versions of the satellite varied in mass, most weighed 11,400 kilograms or 13,300 kg. Satellites were manufactured by Lockheed and the camera was designed by Itek, but produced by Perkin-Elmer. There were 20 launch attempts and one failure.

Mapping imagery

Missions 1205 through 1216 carried a "mapping camera" (also known as a "frame camera") that used 9 inch film and had a moderately low resolution of 9.1 meters (somewhat better than LANDSAT). Intended for mapmaking, photos this camera took cover essentially the entire Earth with at least some images between 1973 and 1980. [NARA ARC database description of "Keyhole-9 (KH-9) Satellite Imagery", accesion number NN3-263-02-011] Almost all the imagery from this camera, amounting to 29,000 images, each covering 3400 square km, was declassified in 2002 as a result of Executive order 12951 [cite web|title=National Archives Releases Recently Declassified Satellite Imagery| date=2002-10-09 | publisher=National Archives and Records Administration press release| url=http://www.archives.gov/press/press-releases/2003/nr03-02.html] , the same order which declassified CORONA, and copies of the films were transferred to the U.S. Geological Survey's Earth Resources Observation Systems office. Images from the mapping camera covering the state of Israel and all imagery from the KH-9's other cameras remain classified. [cite web| title=Historical imagery declassification| |publisher=National Geospatial-Intelligence Agency|url=http://www.nga.mil/portal/site/nga01/index.jsp?epi-content=GENERIC&itemID=5b08f8d62404af00VgnVCMServer23727a95RCRD&beanID=1629630080&viewID=FA ]

The KH-9 was never a backup project for the KH-10 Manned Orbital Laboratory. It was developed solely as a replacement for the Corona search system.Fact|date=July 2007

KH-9 launches

(NSSDC ID Numbers: "See" COSPAR)

Other U.S. imaging spy satellites

*Corona series: KH-1, KH-2, KH-3, KH-4
*KH-5 ARGON, KH-6 LANYARD
*KH-7 and KH-8 GAMBIT
* KH-9 HEXAGON "Big Bird"
*MOL -- KH-10
*KH-11, KH-12, KH-13

Specifications

"Data source:" The Encyclopedia of US Spacecraft.
*Launch vehicle: Titan 3D/Agena
*Total weight: 25,000 to 29,000 pounds (approx.)
*Diameter: 10 feet (approx.)
*Height: 4.5 feet (approx.)
*Orbit: elliptical, 100 miles by 150 miles
*Scanners: television, radio, and high resolution camera

References