Big Bird (satellite)
Encyclopedia
KH-9 HEXAGON, commonly known as 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
United States Air Force
The United States Air Force is the aerial warfare service branch of the United States Armed Forces and one of the American uniformed services. Initially part of the United States Army, the USAF was formed as a separate branch of the military on September 18, 1947 under the National Security Act of...

, all but one were successful. Photographic film
Photographic film
Photographic film is a sheet of plastic coated with an emulsion containing light-sensitive silver halide salts with variable crystal sizes that determine the sensitivity, contrast and resolution of the film...

 aboard Big Bird was sent back to Earth in recoverable film return capsules for processing and interpretation. The best ground resolution achieved by the main cameras was better than 0.6 meters.

They are also officially known as the Broad Coverage Photo Reconnaissance satellites (Code 467), built by Lockheed Corporation
Lockheed Corporation
The Lockheed Corporation was an American aerospace company. Lockheed was founded in 1912 and later merged with Martin Marietta to form Lockheed Martin in 1995.-Origins:...

 for the National Reconnaissance Office
National Reconnaissance Office
The National Reconnaissance Office , located in Chantilly, Virginia, is one of the 16 U.S. intelligence agencies. It designs, builds, and operates the spy satellites of the United States government.-Mission:...

.

The KH-9 was declassified in September 2011 and an example was put on public display for one day..

Development

The KH-9 was originally conceived in the early 1960s as a replacement for the Corona
Corona (satellite)
The Corona program was a series of American strategic reconnaissance satellites produced and operated by the Central Intelligence Agency Directorate of Science & Technology with substantial assistance from the U.S. Air Force...

 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
Photographic film
Photographic film is a sheet of plastic coated with an emulsion containing light-sensitive silver halide salts with variable crystal sizes that determine the sensitivity, contrast and resolution of the 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.

Between September 1966 and July 1967, the contractors for the Hexagon subsystems were selected. LMSC
Lockheed Missiles and Space Company
Lockheed Missiles and Space Company was a unit of the Lockheed Corporation "Missiles, Space, and Electronics Systems Group." LMSC was started by Willis Hawkins who served as its president...

 was awarded the contract for the Satellite Basic Assembly (SBA), Perkin Elmer
PerkinElmer
PerkinElmer, Inc. is an American multinational technology corporation, focused in the business areas of human and environmental health, including environmental analysis, food and consumer product safety, medical imaging, drug discovery, diagnostics, biotechnology, industrial applications, and life...

 for the primary Sensor Subsystem (SS), McDonnell
McDonnell Aircraft
The McDonnell Aircraft Corporation was an American aerospace manufacturer based in St. Louis, Missouri. The company was founded on July 16, 1939 by James Smith McDonnell, and was best known for its military fighters, including the F-4 Phantom II, and manned spacecraft including the Mercury capsule...

 for the Reentry Vehicle (RV), and Itek
Itek
Itek Corporation was a US defense contractor that initially specialized in the field of camera systems for spy satellites. In the early 1960s they built a conglomerate in a fashion similar to LTV or Litton, during which time they developed the first CAD system and explored optical disk technology...

 for the Stellar Index camera (SI). Integration and ground-testing of Satellite Vehicle 1 (SV-1) was completed in May 1971, and it was subsequently shipped to Vandenberg Air Force Base
Vandenberg Air Force Base
Vandenberg Air Force Base is a United States Air Force Base, located approximately northwest of Lompoc, California. It is under the jurisdiction of the 30th Space Wing, Air Force Space Command ....

 in a 70 ft container. Ultimately, four generations ("blocks") of KH-9 Hexagon reconnaissance satellites were developed. KH9-7 (1207) was the first to fly a Block-II panoramic camera and SBA. Block-III (vehicles 13 to 18) included upgrades to electrical distribution and batteries. Two added tanks with ullage control for the Orbit Adjust System (OAS) and new thrusters for the Reaction Control System (RCS) served to increase KH-9's operational lifetime. In addition the Nitrogen supply for the film transport system and the camera vessel was increased. Block-IV was equipped with an extended command system using plated wire memory
Plated wire memory
Plated wire memory is a variation of core memory developed by Bell Laboratories in 1957. Its primary advantage was that it could be machine-assembled, which potentially led to lower prices than the hand-assembled core....

.

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
Mass
Mass can be defined as a quantitive measure of the resistance an object has to change in its velocity.In physics, mass commonly refers to any of the following three properties of matter, which have been shown experimentally to be equivalent:...

; most weighed 11,400 kilograms or 13,300 kg. Satellites were manufactured by Lockheed
Lockheed Corporation
The Lockheed Corporation was an American aerospace company. Lockheed was founded in 1912 and later merged with Martin Marietta to form Lockheed Martin in 1995.-Origins:...

 and the camera was designed by Itek
Itek
Itek Corporation was a US defense contractor that initially specialized in the field of camera systems for spy satellites. In the early 1960s they built a conglomerate in a fashion similar to LTV or Litton, during which time they developed the first CAD system and explored optical disk technology...

, but produced by Perkin-Elmer. There were 20 launch attempts and one failure.

Main camera

The main camera system was designed to take stereo images, with a forward looking camera on the port side, and an aft looking camera on the starboard side. The camera optical layout is a f/3.0 folded Wright Camera
Wright Camera
In astrophotography, the Wright Camera design, presented by Franklin Wright in 1935, just a few years after the introduction of the Schmidt camera, was his "short" alternative to the original arrangement.-Design:...

, with a focal length of 60 in (1.5 m). The system aperture is defined by a 20 in (0.508 m) diameter aspheric
Aspheric lens
An aspheric lens or asphere is a lens whose surface profiles are not portions of a sphere or cylinder. In photography, a lens assembly that includes an aspheric element is often called an aspherical lens....

 corrector plate, which corrects the spherical aberration
Spherical aberration
thumb|right|Spherical aberration. A perfect lens focuses all incoming rays to a point on the [[Optical axis|optic axis]]. A real lens with spherical surfaces suffers from spherical aberration: it focuses rays more tightly if they enter it far from the optic axis than if they enter closer to the...

 of the Wright design. In each of the cameras the ground image passes through the corrector plate to a 45 degree angle flat mirror, which reflects the light to a 0.91 m (35.8 in) diameter concave
Concave
The word concave means curving in or hollowed inward, as opposed to convex. The former may be used in reference to:* Concave lens, a lens with inward-curving surfaces.* Concave polygon, a polygon which is not convex....

 main mirror. The main mirror directs the light through an opening in the flat mirror and through a four-element lens system onto the film platen
Platen
A platen is typically a flat metal plate pressed against a medium to cause an impression in letterpress printing...

. The cameras could scan contiguous areas up to 120 degree wide, and achieved a ground resolution
NIIRS
The National Imagery Interpretability Rating Scale is a subjective scale used for rating the quality of imagery acquired from various types of imaging systems. The NIIRS defines different levels of image quality/interpretability based on the types of tasks an analyst can perform with images of a...

 better than 2 ft (0.6096 m) during the later phase of the project.

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 initially 30 ft (9 m), which improved to 20 ft (6 m) on later missions (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. 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, the same order which declassified CORONA
Corona
A corona is a type of plasma "atmosphere" of the Sun or other celestial body, extending millions of kilometers into space, most easily seen during a total solar eclipse, but also observable in a coronagraph...

, 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
Israel
The State of Israel is a parliamentary republic located in the Middle East, along the eastern shore of the Mediterranean Sea...

 and all imagery from the KH-9's other cameras remain classified.

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.

High-altitude atmospheric density

Missions 1205 to 1207 carried Doppler beacons
Doppler radar
A Doppler radar is a specialized radar that makes use of the Doppler effect to produce velocity data about objects at a distance. It does this by beaming a microwave signal towards a desired target and listening for its reflection, then analyzing how the frequency of the returned signal has been...

 to help map the atmospheric density at high altitudes
Thermosphere
The thermosphere is the biggest of all the layers of the Earth's atmosphere directly above the mesosphere and directly below the exosphere. Within this layer, ultraviolet radiation causes ionization. The International Space Station has a stable orbit within the middle of the thermosphere, between...

 in an effort to understand the effect on ephemeris predictions. The measurements of the atmospheric density were released through NASA.

ELINT subsatellites

Missions 1203, 1207, 1208, 1209, and 1212 to 1219 included Ferret ELINT subsatellites, which were launched into a higher orbit to catalogue Soviet air defence radars, eavesdrop on voice communications, and tape missile and satellite telemetry. Missions 1210 to 1212 also included scientific subsatellites.

KH-9 missions

Name Block Mission no. Launch date NSSDC ID Other Name Launch vehicle Orbit Decay date
KH9-1 I 1201 1971 June 15 1971-056A OPS 7809 Titan IIID
Titan IIID
The Titan IIID or Titan 3D was an American expendable launch system, launched twenty two times with KH-9 and KH-11 satellites between 1971 and 1982...

184.0 km x 300.0 km, i=96.4° 1971 Aug 06
KH9-2 I 1202 1972 Jan 20 1972-002A OPS 1737 Titan IIID 157.0 km x 331.0 km, i=97.0° 1972 Feb 29
KH9-3 I 1203 1972 Jul 7 1972-052A OPS 7293 Titan IIID 174.0 km x 251.0 km, i=96.9° 1972 Sep 13
KH9-4 I 1204 1972 Oct 10 1972-079A OPS 8314 Titan IIID 160.0 km x 281.0 km, i=96.5° 1973 Jan 08
KH9-5 I 1205 1973 Mar 9 1973-014A OPS 8410 Titan IIID 152.0 km x 270.0 km, i=95.7° 1973 May 19
KH9-6 I 1206 1973 Jul 13 1973-043A OPS 8261 Titan IIID 156.0 km x 269.0 km, i=96.2° 1973 Oct 12
KH9-7 II 1207 1973 Nov 10 1973-088A OPS 6630 Titan IIID 159.0 km x 275.0 km, i=96.9° 1974 Mar 13
KH9-8 II 1208 1974 Apr 10 1974-020A OPS 6245 Titan IIID 153.0 km x 285.0 km, i=94.5° 1974 Jul 28
KH9-9 II 1209 1974 Oct 29 1974-085A OPS 7122 Titan IIID 162.0 km x 271.0 km, i=96.7° 1975 Mar 19
KH9-10 II 1210 1975 Jun 8 1975-051A OPS 6381 Titan IIID 157.0 km x 234.0 km, i=96.3° 1975 Nov 05
KH9-11 II 1211 1975 Dec 4 1975-114A OPS 4428 Titan IIID 157.0 km x 234.0 km, i=96.7° 1976 Apr 01
KH9-12 II 1212 1976 Jul 8 1976-065A OPS 4699 Titan IIID 159.0 km x 242.0 km, i=97.0° 1976 Dec 13
KH9-13 III 1213 1977 Jun 27 1977-056A OPS 4800 Titan IIID 155.0 km x 239.0 km, i=97.0° 1977 Dec 23
KH9-14 III 1214 1978 Mar 16 1979-029A OPS 0460 Titan IIID 172.0 km x 218.0 km, i=96.4° 1978 Sep 11
KH9-15 III 1215 1979 Mar 16 1979-025A OPS 3854 Titan IIID 177.0 km x 256.0 km, i=96.3° 1979 Sep 22
KH9-16 III 1216 1980 Jun 18 1980-052A OPS 3123 Titan IIID 169.0 km x 265.0 km, i=96.5° 1981 Mar 06
KH9-17 III 1217 1982 May 11 1982-041A OPS 5642 Titan IIID 177.0 km x 262.0 km, i=96.4° 1982 Dec 05
KH9-18 III 1218 1983 Jun 20 1983-060A OPS 0721 Titan 34D
Titan 34D
The Titan 34D was an American rocket, used to launch a number of satellites for mostly military applications. After its retirement from military service, a small number were converted to the Commercial Titan III configuration, which included a stretched second stage, and a larger fairing...

163.0 km x 224.0 km, i=96.4° 1984 Mar 21
KH9-19 IV 1219 1984 Jun 25 1984-065A USA 2 Titan 34D 170.0 km x 230.0 km, i=96.5° 1984-10-18
KH9-20 IV 1220 1986 Apr 18 1986-F03 (launch failed) Titan 34D -

(NSSDC ID Numbers: See COSPAR
COSPAR
The Committee on Space Research was established by the International Council for Science in 1958.Among COSPAR's objectives are the promotion of scientific research in space on an international level, with emphasis on the free exchange of results, information, and opinions, and providing a forum,...

)

Cost

The total cost of the 20 flight KH-9 program from FY1966 to FY1986 was US$ 3.262 billion in respective year dollars.

Specifications

Data source: The Encyclopedia of US Spacecraft and NSSDC
  • Launch vehicle: Titan IIID/34D
  • Total weight: 11400 kg (25,132.7 lb), with mapping camera 13300 kg (29,321.5 lb)
  • Reentry weight: 5330 kg (11,750.6 lb)
  • max. Diameter (main body): 3.05 m (120.1 in)
  • Length (with mapping camera): 16.21 m (638.2 in)
  • Orbit: elliptical, 100 miles by 150 miles
  • Scanners: television, radio, and high resolution camera

Photo Gallery


File:HEXAGON 11.png|
File:HEXAGON 12.png|
File:HEXAGON Film being despooled.png|
File:HEXAGON Factory to Launch sequence.png
File:HEXAGON Forward section with mapping camera.png
File:HEXAGON Re-entry vehicle.png
File:HEXAGON Reaction Control Module.png
File:HEXAGON satellite vehicle transporter.png
File:HEXAGON Shroud and Base in Acoustic Chamber.png
File:KH-9 HEXAGON satellite 2.jpg
File:KH-9 HEXAGON satellite.jpg
File:KH9 Hexagon integration.png
File:KH9 HEXAGON profile.png

Other U.S. imaging spy satellites

  • Corona
    Corona (satellite)
    The Corona program was a series of American strategic reconnaissance satellites produced and operated by the Central Intelligence Agency Directorate of Science & Technology with substantial assistance from the U.S. Air Force...

     series: KH-1, KH-2, KH-3, KH-4
  • KH-5
    KH-5
    KH-5 ARGON was a series of reconnaissance satellites produced by the United States from February 1961 to August 1964. The KH-5 operated similarly to the Corona series of satellites, as it ejected a canister of photographic film. At least 12 missions were attempted, but at least 7 resulted in...

     ARGON, KH-6
    KH-6
    Codenamed Lanyard, the KH-6 was the unsuccessful first attempt to develop and deploy a high-resolution optical reconnaissance satellite by the United States National Reconnaissance Office. Launches and launch attempts spanned the period from March to July 1963. The project was quickly put together...

     LANYARD
  • KH-7
    KH-7
    Codenamed Gambit, the KH-7 was a reconnaissance satellite used by the United States from July 1963 to June 1967. Like the older CORONA system, it acquired imagery intelligence by taking photographs and returning the undeveloped film to earth. It achieved a typical ground-resolution of to...

     and KH-8
    KH-8
    The KH-8, codenamed Gambit 3 was a long-lived series of reconnaissance satellites of the "Key Hole" series used by the United States from July 1966 to April 1984, and also known as Low Altitude Surveillance Platform. The satellite ejected canisters of photographic film that were retrieved as they...

     GAMBIT
  • KH-9 HEXAGON "Big Bird"
  • MOL
    Manned Orbiting Laboratory
    The Manned Orbiting Laboratory , originally referred to as the Manned Orbital Laboratory, was part of the United States Air Force's manned spaceflight program, a successor to the cancelled Boeing X-20 Dyna-Soar military reconnaissance space plane project...

     -- KH-10
  • KH-11
    KH-11
    The KH-11 KENNAN, renamed CRYSTAL in 1982 and also referenced by the codenames 1010, and "Key Hole", is a type of reconnaissance satellite launched by the American National Reconnaissance Office since December 1976...

    , KH-13
    KH-13
    Enhanced Imaging System , officially referred to as "Enhanced Imagery System", previously known as 8X, and sometimes unofficially known as Misty 2 and KH-13, is an American reconnaissance satellite programme...


External links

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