U.S. Satellite Imagery, 1960-1999
National Security Archive Electronic Briefing Book No. 13
Edited by Jeffrey T. Richelson
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Washington, D.C., April 14, 1999 – The use of overhead platforms to observe events on the earth can be traced to the French Revolution, when France organized a company of aerostiers, or balloonists, in April 1794. The United States employed balloons during the Civil War, although little intelligence of value was obtained. In January 1911, the San Diego waterfront became the first target of cameras carried aboard an airplane. Later that year the U.S. Army Signal Corps put aerial photography into the curriculum at its flight training school. Between 1913 and 1915 visual and photographic reconnaissance missions were flown by the U.S. Army in the Philippines and along the Mexican border.1
During World War II the United States made extensive use of airplane photography using remodeled bombers. After the war, with the emergence of a hostile relationship with the Soviet Union, the United States began conducting photographic missions along the Soviet periphery. The aircraft cameras, however, could only capture images of territory within a few miles of the flight path.
On some missions aircraft actually flew into Soviet airspace, but even those missions did not provide the necessary coverage of the vast Soviet interior. As a result, beginning in the early 1950s the United States began seriously exploring more advanced methods for obtaining images of targets throughout the Soviet Union. The result was the development, production, and employment of a variety of spacecraft and aircraft (particularly the U-2 and A-12/SR-71) that permitted the U.S. intelligence community to closely monitor developments in the Soviet Union and other nations through overhead imagery.
The capabilities of spacecraft and aircraft have evolved from being limited to black-and-white visible-light photography to being able to produce images using different parts of the electromagnetic spectrum. As a result, imagery can often be obtained under circumstances (darkness, cloud cover) where standard visible-light photography is not feasible. In addition, employment of different portions of the electromagnetic spectrum, individually or simultaneously, expands the information that can be produced concerning a target.
Photographic equipment can be film-based or electro-optical. A conventional camera captures a scene on film by recording the varying light levels reflected from all of the separate objects in the scene. In contrast, an electro-optical camera converts the varying light levels into electrical signals. A numerical value is assigned to each of the signals, which are called picture elements, or pixels. At a ground receiving station, a picture can then be constructed from the digital signal transmitted from the spacecraft (often via a relay satellite).2
In addition to the visible-light portion of the electro-magnetic spectrum, the near-infrared portion of the spectrum, which is invisible to the human eye, can be employed to produce images. At the same time, near-infrared, like, visible-light imagery, depends on objects reflecting solar radiation rather than on their emission of radiation. As a result, such imagery can only be produced in daylight and in the absence of substantial cloud cover.3
Thermal infrared imagery, obtained from the mid- and far-infrared portions of the electromagnetic spectrum, provides imagery purely by detecting the heat emitted by objects. Thus, a thermal infrared system can detect buried structures, such as missile silos or underground construction, as a result of the heat they generate. Since thermal infrared imagery does not require visible light, it can be obtained under conditions of darkness--if the sky is free of cloud cover.4
Imagery can be obtained during day or night in the presence of cloud cover by employing an imaging radar (an acronym for radio detection and ranging). Radar imagery is produced by bouncing radio waves off an area or an object and using the reflected returns to produce an image of the target. Since radio waves are not attenuated by the water vapor in the atmosphere, they are able to penetrate cloud cover.5
However imagery is obtained, it requires processing and interpretation to convert it into intelligence data. Computers can be employed to improve the quantity and quality of the information extracted. Obviously, digital electro-optical imagery arrives in a form that facilitates such operations. But even analog imagery obtained by a conventional camera can be converted into digital signals. In any case, a computer disassembles a picture into millions of electronic Morse code pulses and then uses mathematical formulas to manipulate the color contrast and intensity of each spot. Each image can be reassembled in various ways to highlight special features and objects that were hidden in the original image.6
Such processing allows:
Such processing plays a crucial role in easing the burden on photogrammetrists and imagery interpreters. Photogrammetrists are responsible for determining the size and dimensions of objects from overhead photographs, using, along with other data, the shadows cast by the objects. Photo interpreters are trained to provide information about the nature of the objects in the photographs--based on information as to what type of crates carry MiG-29s, for instance, or what an IRBM site or fiber optics factory looks like from 150 miles in space.
Click on any of the following images to view a larger version of the photo.
CORONA, ARGON, and LANYARDIn its May 2, 1946 report, Preliminary Design for an Experimental World Circling Spaceship, the Douglas Aircraft Corporation examined the potential value of satellites for scientific and military purposes. Possible military uses included missile guidance, weapons delivery, weather reconnaissance, communications, attack assessment, and "observation."8
A little less than nine years later, on March 16, 1955, the Air Force issued General Operational Requirement No. 80, officially establishing a high-level requirement for an advanced reconnaissance satellite. The document defined the Air Force objective to be the provision of continuous surveillance of "preselected areas of the earth" in order "to determine the status of a potential enemy's warmaking capability."9
Over the next five years the U.S. reconnaissance satellite program evolved in a variety of ways. The success of the Soviet Union's Sputnik I and II satellites in the fall of 1957 provided a spur to all U.S. space programs - as any success could be used in the propaganda war with the Soviet Union. In the case of U.S. reconnaissance programs, Sputnik provided a second incentive. The clear implications of the Sputnik launches for Soviet ICBM development increased the pressure on discovering the extent of Soviet capabilities - something that the sporadic U-2 flights could only do in a limited fashion.10
The Air Force program was first designated the Advanced Reconnaissance System (ARS), then SENTRY, and finally SAMOS. Management responsibility for SAMOS was transferred from the Air Force to the Advanced Research Projects Agency (ARPA), established on February 7, 1958, and then back to the Air Force in late 1959.11
Concern about the the length of time it would take to achieve the primary objective of the SAMOS program - a satellite that could scan its exposed film and return the imagery electronically - led to President Dwight Eisenhower's approval, also on February 7, 1958, of a CIA program to develop a reconnaissance satellite. The CIA program, designated CORONA, focused on development of a satellite that would physically return its images in a canister - an objective which had been a subsidiary portion of the SAMOS program.12
While all the various versions of the SAMOS program would be canceled in the early 1960s, CORONA would become a mainstay of the U.S. space reconnaissance program for over a decade. It would take over a year, starting in 1959, and 14 launches before an operational CORONA spacecraft was placed in orbit. Nine of the first twelve launches carried a camera that was intended to photograph areas of the Soviet Union and other nations. All the flights ended in failure for one reason or another. The thirteenth mission, a diagnostic flight without camera equipment, was the first success - in that a canister was returned from space and recovered at sea.13
Then on August 18, a CORONA was placed into orbit, orbited the Earth for a day, and returned its canister to earth, where it was snatched out the air by a specially equipped aircraft on August 19. The camera carried on that flight would be retroactively designated the KH-1 (KH for KEYHOLE) and was cable of producing images with resolution in the area of 25-40 feet - a far cry from what would be standard in only a few years. It did yield, however, more images of the Soviet Union in its single day of operation than did the entire U-2 program.14
The next successful CORONA mission would be conducted on December 7, 1960. This time a more advanced camera system, the KH-2, would be on board. From that time, through the end of the CORONA program in 1972, there would be a succession of new camera systems - the KH-3, KH-4, KH-4A, and KH-4B - which produced higher-resolution images than their predecessors, ultimately resulting in a system that could yield images with approximately 5-6' resolution. In addition, two smaller programs - ARGON (for mapping) and LANYARD (motivated by a specific target in the Soviet Union) - operated during the years 1962-1964 and 1963 respectively. All together there were 145 missions, which yielded over 800,000 images of the Soviet Union and other areas of the world.15
Those images dramatically improved U.S. knowledge of Soviet and other nations capabilities and activities. Perhaps its major accomplishment occurred within 18 months of the first successful CORONA mission. Accumulated photography allowed the U.S. intelligence community to dispel the fear of missile gap, with earlier estimates of a Soviet ICBM force numbering in the hundreds by mid-1962 becoming, in September 1961, an estimate of between 25 and 50. By June 1964 CORONA satellites had photographed all 25 Soviet ICBM complexes. CORONA imagery also allowed the U.S. to catalog Soviet air defense and anti-ballistic missile sites, nuclear weapons related facilities, submarine bases, IRBM sites, airbases - as well as Chinese, East European, and other nations military facilities. It also allowed assessment of military conflicts - such as the 1967 Six-Day War - and monitoring of Soviet arms control compliance.16
In February 1995, President Clinton signed an executive order that declassified those images. 17
A KH-4A image of Dolon airfield, which was a major Soviet long-range aviation facility located in what is now the Republic of Kazakhstan. The image shows two regiments of Tupolev (Tu-16) Bear bombers. The main runway is 13,200 feet long.
The KH-4A camera system was first introduced in August 1963. Resolution
ranged from 9 to 25 feet.
A KH-4B image of the Moscow, with an insert of the Kremlin. In the enlargement of the Kremlin, individual vehicles can be identified as trucks or cars, and the line of people waiting to enter Lenin's Tomb in Red Square can be seen. According to the CIA, the photograph "illustrates some of the best resolution imagery acquired by the KH-4B camera system."
The KH-4B was first introduced in September 1967 and generally produced
images with 6 foot resolution.
A KH-4B of image, taken on February 11, 1969 of a Taiwanese nuclear
facility. The United States intelligence community, relying on CORONA and
other forms of intelligence, has closely monitored the nuclear facilities
of both adversaries such as the Soviet Union and the PRC and those of friendly
nations such as Taiwan and Israel.
The Next GenerationsThe primary objective of the CORONA program was to provide "area surveillance" coverage of the Soviet Union, China and other parts of the world. Thus, CORONA yielded single photographs which covered thousands of square miles of territory - allowing analysts to both examine images of known targets and to search for previously undetected installations or activities that would be of interest to the U.S. intelligence community.
The GAMBIT program provided an important complement to CORONA. Initiated in 1960, it yielded the first "close-look" or "spotting" satellite. The emphasis of GAMBIT operations, which commenced in 1963 and continued through part of 1984, was to produce high-resolution imagery on specific targets (rather than general areas). Such resolution would allow the production of more detailed intelligence, particularly technical intelligence on foreign weapons systems. The first GAMBIT camera, the KH-7, could produce photos with about 18 inch resolution, while the second and last model, the KH-8 was capable of producing photographs with under 6 inch resolution.18
While the Air Force concentrated on the high-resolution systems, the CIA (after numerous bureaucratic battles) was assigned responsibility for the next generation area surveillance program. That program, which came to be designated HEXAGON, resulted in satellites carrying the KH-9 camera system - capable of producing images covering even more territory than the CORONA satellites, with a resolution of 1-2 feet. Eighteen HEXAGON satellites would be launched into orbit between 1971 and 1984, when the program terminated.19
In late 1976, a new capability was added when the satellite carrying the KH-11 optical system was placed into orbit. Unlike its predecessors, the KH-11, also known by the program code names KENNAN and CRYSTAL, did not return film canisters to be recovered and interpreted. Rather, the light captured by its optical system was transformed into electronic signals and relayed (through a relay satellite in a higher orbit) back to a ground station, where the signals were recorded on tape and converted into an image. As a result, the U.S. could obtain satellite images of a site or activity virtually simultaneously with a satellite passing overhead.20
The 1980s saw a number of inadvertent or unauthorized disclosures of U.S. satellite imagery. In 1980, as a result of the fiasco at Desert One, where U.S. forces landed in preparation for an attempt to rescue U.S. hostages held in Iran, KH-11 imagery of possible evacuation sites in Tehran was left behind. In 1981, Aviation Week & Space Technology published a leaked (and degraded) KH-11 photo of a Soviet bomber at Ramenskoye Airfield.
In 1984, two images of Soviet aircraft, taken by a KH-8 or KH-9 satellite, were inadvertently published in Congressional hearings. That same year, an employee of the Naval Intelligence Support Center provided Jane's Defence Weekly with several images taken by a KH-11 satellite of a Soviet naval shipbuilding facility.21
This 1984 computer enhanced KH-11 photo, taken at an oblique angle
was leaked, along with two others, to Jane's Defence Weekly by naval
intelligence analyst, Samuel Loring Morison. The image shows the
general layout of the Nikolaiev 444 shipyard in the Black Sea. Under
construction is a Kiev- class aircraft carrier (shown in the left side
of the photo), then known as the Kharkov, along with an amphibious
These satellite photographs, showing a MiG-29 FULCRUM and SU- 27 FLANKER,
were shown to the House Appropriations Committee during 1984 budget hearings.
They were then published, apparently by mistake, in the sanitized
version of the hearings released to the public. During the 1985 trial
of Samuel Loring Morison, government prosecutors would acknowledge
the photographs were satellite images, produced by a system other
than the KH-11.
Current SystemsThe United States is presently operating at least two satellite imaging systems. One is an advanced version of the KH-11, three of which have been launched, the first in 1992.
The advanced KH-11 satellites have a higher orbit than that exhibited by their predecessors--operating with perigees of about 150 miles and apogees of about 600 miles. In addition, they also have some additional capabilities. They contain an infrared imagery capability, including a thermal infrared imagery capability, thus permitting imagery during darkness. In addition, the satellites carry the Improved CRYSTAL Metric System (ICMS), which places the necessary markings on returned imagery to permit its full exploitation for mapping purposes. Additionally, the Advanced KH-11 can carry more fuel than the original model, perhaps 10,000 to 15,000 pounds. This permits a longer lifetime for the new model--possibly up to eight years.22
A second component of the U.S. space imaging fleet, are satellites developed and deployed under a program first known as INDIGO, then as LACROSSE, and most recently as VEGA. Rather than employing an electro-optical system they carry an imaging radar. The satellites closed a major gap in U.S. capabilities by allowing the U.S. intelligence community to obtain imagery even when targets are covered by clouds.23
The first VEGA was launched on December 2, 1988 from the space shuttle orbiter Atlantis (and deorbited in July 1997). A second was orbited in March 1991, from Vandenberg AFB on a Titan IV, and a third in October 1997. The satellites have operated in orbits of approximately 400 miles and at inclinations of 57 and 68 degrees respectively.24
When conceived, the primary purpose envisioned for the satellite was monitoring Soviet and Warsaw Pact armor. Recent VEGA missions included providing imagery for bomb damage assessments of the consequences of Navy Tomahawk missile attacks on Iraqi air defense installations in September 1996, monitoring Iraqi weapons storage sites, and tracking Iraqi troop movements such as the dispersal of the Republican Guard when the Guard was threatened with U.S. attack in early 1998. VEGA has a resolution of 3-5 feet, with its resolution reportedly being sufficient to allow discrimination between tanks and armored personnel carriers and identification of bomb craters of 6-10 feet in diameter.25
The LACROSSE/VEGA satellite that was launched in October 1997
may be the first of a new generation of radar imagery satellites. The new
generation will apparently have greater resolution, and constellation size
may be increased from 2 to 3.26
An advanced KH-11 photograph of the Shifa Pharmaceutical Plant, Sudan. This degraded photo, of approximately 1-meter resolution, was officially released after the U.S. attack on the plant in August 1998 in retaliation for attacks on two U.S. embassies in Africa. The U.S. alleged, at least partially on the basis of soil samples, that the plant was involved in the production of chemical weapons.
A degraded advanced KH-11 photograph of the Zhawar Kili Base Camp (West), Afghanistan, which housed training facilities for Osama Bin Laden's terrorist organization.
The photograph was used by Secretary of Defense William S. Cohen and General Henry H. Shelton, the Chairman of the Joint Chiefs of Staff to brief reporters on the U.S. cruise missile attack on the facility.
One of over twenty degraded advanced KH-11 photos, released by the Department of Defense in December 1998 during Operation Desert Fox. The higher resolution, and classified, version of the image was used by imagery interpreters at the National Imagery and Mapping Agency to assess the damage caused by U.S. airstrikes.
A degraded advanced KH-11 photo of Al Sahra Airfield, Iraq, used by Vice Adm. Scott A. Fry, USN, Director, J-3 and Rear Admiral Thomas R. Wilson, USN, Joint Staff intelligence director in a Pentagon press briefing on December 18, 1998.
The arrows in this degraded advanced KH-11 image, used in a Pentagon press briefing on December 19, 1998, show two areas where the Secretariat Presidential was damaged due to Operation Desert Fox airstrikes.
Pre-strike assessment photograph of the Belgrade Army Garrison and headquarters, Serbia.
Post-strike damage assessment photograph of the Belgrade Army
Garrison and Headquarters, Serbia, attacked during Operation Allied Force.
Commercial ImageryThe U.S. intelligence community has also used imagery, including multispectral imagery, produced by two commercial systems --LANDSAT and SPOT. The LANDSAT program began in 1969 as an experimental National Aeronautics and Space Administration (NASA) program, the Earth Resources Technology Satellite (ERTS). Currently there are two operating LANDSAT satellites--LANDSAT 4 and LANDSAT 5--launched in 1982 and 1984.27
LANDSATs 4 and 5 operate in 420 mile sun-synchronous orbits and each carries a Thematic Mapper (TM), an upgraded version of the Multispectral Scanner (MSS) on earlier LANDSATs. A typical LANDSAT images is 111 by 102 miles, providing significant broad area coverage. However, the resolution of the images is approximately 98 feet--making them useful for only the coarsest intelligence tasks.
SPOT, an acronym for Le Systeme Pour l'Observation de la Terre, is operated by the French national space agency. SPOT 1 was launched in 1986, followed by three additional satellites at approximately four year intervals. SPOT satellites operate in about 500-mile orbits, and carry two sensor systems. The satellites can return black and white (panchromatic) images with 33 foot resolution and multispectral images with 67 foot resolution. The images are of higher-resolution than LANDSAT's but cover less territory-- approximately 36 miles by 36 miles.28
U.S. intelligence community use of commercial imagery will expand dramatically in the coming years if the new generation of commercial imaging satellites lives up to expectations--which include images with 1-meter resolution. Such imagery and the reduced cost of attaining it when purchased commercially will permit the U.S. intelligence community to fill part of its needs via such commercial systems.
Among the commercial satellites that are expected to produce high resolution imagery are the Ikonos satellites to be launched by Space Imaging Eosat (which also operates the LANDSAT satellites). The first of the satellites, scheduled to be launched in the summer of 1999 from Vandenberg AFB, is designed to generate 1-meter panchromatic and 4-meter multispectral images. A similar satellite is scheduled for launch in September 1998.29
Also promising to provide 1-meter panchromatic imagery and 4-meter multispectral imagery are the satellites to be developed by EarthWatch and Orbital Sciences. EarthWatch's 1-meter resolution Quickbird satellite is scheduled for launch in late 1998 or 1999. Orbital Science's OrbView-3 satellite is to be launched in 1999. It is expected to have a 3-5 year lifetime and produce images covering 5x5 mile segments with 1-meter resolution.30
An overhead photograph of Mountain View, California that that has been
digitally scanned to represent the one-meter imagery that the Ikonos
satellites are expected to provide.
Notes1. William Burrows, Deep Black: Space Espionage and National Security (New York, N.Y.: Random House, 1986), pp. 28, 32.
2. Farouk el-Baz, "EO Imaging Will Replace Film in Reconnaissance," Defense Systems Review (October 1983): 48-52.
3. Richard D. Hudson Jr. and Jacqueline W. Hudson, "The Military Applications of Remote Sensing by Infrared," Proceedings of the IEEE 63, 1 (1975): 104-28.
4. Ibid.; Bruce G. Blair and Garry D. Brewer, "Verifying SALT," in William Potter (ed.), Verification and SALT: The Challenge of Strategic Deception (Boulder, Co.: Westview, 1980), pp. 7-48.
5. Homer Jensen, L.C. Graham, Leonard J. Porcello, and Emmet N. Leith, "Side-looking Airborne Radar," Scientific American, October 1977, pp. 84-95.
6. Paul Bennett, Strategic Surveillance (Cambridge, Ma.: Union of Concerned Scientists, 1979), p. 5.
7. Richard A. Scribner, Theodore J. Ralston, and William D. Mertz, The Verification Challenge: Problems and Promise of Strategic Nuclear Arms Verification (Boston: Birkhauser, 1985), p. 70; John F. Ebersole and James C. Wyant, "Real-Time Optical Subtraction of Photographic Imagery for Difference Detection," Applied Optics, 15, 4 (1976): 871-76.
8. Robert L. Perry, Origins of the USAF Space Program, 1945-1956 (Washington, D.C.: Air Force Systems Command, June 1962), p. 30.
9. Ibid., pp. 42-43.
10. On the impact of Sputnik, see Robert A. Divine, The Sputnik Challenge: Eisenhower's Response to the Soviet Satellite (New York: Oxford, 1993).
11. Jeffrey T. Richelson, America's Secret Eyes in Space: The U.S. KEYHOLE Spy Satellite Program (New York: Harper & Row, 1990), pp. 26-30.
12. Kenneth E. Greer, "Corona," Studies in Intelligence, Supplement, 17 (Spring 1973): 1-37, reprinted in Kevin C. Ruffner (ed.), CORONA: America's First Satellite Program (Washington, D.C.: CIA, 1995).
14. Ibid.; Robert A. McDonald, "CORONA: Success for Space Reconnaissance, A Look into the Cold War, and a Revolution in Intelligence," Photogrammetric Engineering & Remote Sensing 61,6
(June 1995): 689-720.
15. McDonald, "CORONA: Success for Space Reconnaissance ...".
16. Robert A. McDonald, "Corona's Imagery: A Revolution in Intelligence and Buckets of Gold for National Security," in Robert A. McDonald (ed)., CORONA: Between the Sun and the Earth - The First NRO Reconnaissance Eye in Space (Baltimore: American Society of Photogrammetry and Remote Sensing, 1997), pp. 211-220; Greer, "CORONA"; Frank J. Madden, The CORONA Camera System, Itek's Contribution to World Stability (Lexington, Mass.: Itek, May 1997), p. 6.
17. Executive Order 12951, Release of Imagery Acquired by Space-Based National Intelligence Reconnaissance Systems, February 24, 1995.
18. Richelson, America's Secret Eyes in Space, pp. 77-78, 359-60.
19. Ibid., pp. 105-21, 361-62.
20. Ibid., pp. 123-143, 362.
21. Burrows, Deep Black, photo section.
22. Richelson, America's Secret Eyes in Space, p. 231; Craig Covault, "Advanced KH-11 Broadens U.S. Recon Capability," Aviation Week & Space Technology, January 6, 1997, pp. 24-25.
23. Bob Woodward, VEIL: The Secret Wars of the CIA, 1981-1987 (New York: Simon & Schuster, 1987), p. 221.
24. Jeffrey T. Richelson, The U.S. Intelligence Community 4th ed. (Boulder, Co.: Westview, 1999), p. 155.
26. David Fulghum and Craig Covault, "U.S. Set to Launch Upgraded Lacrosse," Aviation Week & Space Technology September 20, 1996, p.34;
27. Bob Preston, Plowshares and Power: The Military Use of Civil Space (Washington, D.C.: NDU Press, 1994), pp. 55-56; Richelson, The U.S. Intelligence Community, p. 159.
28. Richelson, The U.S. Intelligence Community, p. 159.
29. Joseph C. Anselmo, "Space Imaging Readies 1-Meter Satellite,"
Aviation Week & Space Technology, May 19, 1997, p. 26; "Ikonos 1 Undergoes Tests as Launch Nears," Space News, May 11-17, 1998, p. 19; "Commercial Developments," Aviation Week & Space Technology, June 29, 1998, p. 17.
30. Richelson, The U.S. Intelligence Community, pp. 160-61.