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Screen capture from Northrop-Grumman video on the DSP Program

Space-Based Early Warning: From MIDAS to DSP to SBIRS

Last DSP satellite to be launched tomorrow

National Security Archive Electronic Briefing Book No. 235
Edited by Jeffrey T. Richelson

Posted - November 9, 2007


For more information contact:
Jeffrey T. Richelson - 202/994-7000

Video: Northrop-Grumman video on the DSP Program

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America's Space Sentinels: DSP Satellites and National Security
By Jeffrey T. Richelson


Washington D.C., November 9, 2007 - In anticipation of the planned launch of the final Defense Support Program (DSP) satellite tomorrow evening, which was originally scheduled to be orbited in October 2005, the National Security Archive has posted on the Web a collection of declassified documents tracing the history of the program from its roots as Subsystem G of WS-117L in 1957. At that time the U.S. began seriously planning to deploy satellites that would detect the infrared signals emitted by intercontinental ballistic missiles in order to provide warning of a Soviet missile attack.

The documents posted today, obtained through the Freedom of Information Act and archival research, include documents on the theoretical work behind the concept of space-based missile detection, the early doubts about the feasibility of such detection, and 1960s research and development work on the Missile Defense Alarm System (MIDAS). They also include documents on the evolution of the DSP--with regard both to its capabilities and its use for a variety of additional missions, including the detection of intermediate-range missiles, bombers flying on afterburner and spacecraft. In addition, a number of documents focus on the decades-long search for a follow-on system to DSP.

Compiled by National Security Archive Senior Fellow Dr. Jeffrey T. Richelson, the documents in this briefing book originated with the Defense Department, Air Force, U.S. Space Command, Air Force Space Command, Air Force Space and Missile Systems Center, Aerospace Corporation, Government Accounting Office, and other organizations.

Electronic Briefing Book
Space-Based Early Warning: From MIDAS to DSP to SBIRS
By Jeffrey T. Richelson

As early as 1948, U.S. government scientists were investigating the possibility of detecting and tracking ballistic missiles by the heat generated when they were launched, including the heat or infrared signals from their missile plumes. In 1955, the work of two members of the RAND Corporation staff, William Kellogg and Sidney Passman, on infrared detection of missiles "captured the attention of various science advisory committees" and created support for development of an infrared warning satellite. (Document 1, Document 2).

The next year, the Air Force selected the Lockheed Corporation to build a photographic reconnaissance satellite. Lockheed proposed a number of additional systems, including a satellite equipped with an infrared radiometer and telescope to detect both the hot exhaust gases emitted by long-range jet bombers and large rockets as they climbed through the atmosphere. As a result, before the end of 1957, Lockheed's proposal became Subsystem G of Weapons System 117 (WS-117L), the overall Defense Department space-based reconnaissance and surveillance program. (Note 1)

By early November 1958, Subsystem G had become MIDAS - the Missile Defense Alarm System (MIDAS). Throughout 1959 and for a number of years afterwards plans for a future MIDAS constellation were drawn up and revised-with the number of satellites and their orbital characteristics changing from plan to plan. Thus, a January 1959 plan recommended an operational constellation of twenty spacecraft operating at 1,000 miles while a revised plan, produced later that year, envisioned a constellation of twelve spacecraft at 2,000-mile altitudes. (Note 2)

Between 1959 and the end of 1963 there were three salient features to the MIDAS program-revised plans, internal and external reviews of the feasibility of MIDAS (and indeed of the whole concept of infrared detection from space), and the launch of test satellites. While some were afraid that background radiance and cloud clutter, among other potential problems, would prevent an effective system from being developed, others in the Air Force and contractor organizations were more optimistic. (Document 3 and Document 4)

The attempt to determine the feasibility of MIDAS began on February 26, 1960, when MIDAS 1 was launched from the Atlantic Missile Range. Unfortunately, the satellite and booster never separated and landed in the Atlantic Ocean. MIDAS-2 was successfully orbited on May 24, 1960, but the transmission of infrared data to a ground readout station lasted only for a brief time before the satellite's communication link failed. It would not be until the launch of MIDAS 7, on May 9, 1963, that a MIDAS satellite would clearly demonstrate the ability to detect missile launches-detecting the launch of both Minuteman and Polaris missiles, whose launch had been scheduled to provide a test for MIDAS. While a booster malfunction prevented MIDAS 8 from reaching orbit, MIDAS 9 was also successful in detecting missile launches. (Note 3) (Document 8)

Despite the success of MIDAS 7 and 9, there was no immediate move to deploy an operational system, as there were still issues concerning costs and the exact capabilities a warning satellite might also have, such as the ability to detect to the signatures of a nuclear detonation. In 1966, a new series of test launches began with the objective of demonstrating that the satellites could operate for as many as six months and detect submarine-launched and medium-range missiles as well as ICBMs. The tests were also intended to demonstrate the ability to detect launch points to within eight to ten miles. (Document 9)

Three tests were conducted in 1966-in June, August, and October. While the first mission failed due to booster problems, the next two were successful. One or both of the two successful missions detected the infrared signature of SS-N-6 missiles, which was extraordinarily dim-thus demonstrating the sensor's ability to detect a wide range of missiles, both liquid and solid-fueled. As a result, the decision was made to go ahead with construction and deployment of an operational constellation of early warning satellites. (Note 4)

The satellites launched in 1966 were part of Program 461, as MIDAS had become known before the end of 1963. The program to produce an operational constellation was first known as Program 949, then Program 647, and then finally designated the Defense Support Program (DSP). In contrast to the satellites associated with the MIDAS and 461 programs, which orbited about 2,000 miles above the earth, the DSP satellites were supposed to be launched into a geostationary orbit-22,300 miles above a point on the equator, allowing them to maintain a constant view of the third of the earth that their sensor could monitor. While the first of those satellites, launched on November 5, 1970, would fail to attain the proper orbit, the second did, placing it a position over the equator that allowed it to monitor Soviet and Chinese missile launches. (Note 5)

After two more successful launches, the U.S. established a three-satellite DSP constellation-with satellite stations over the Atlantic, Pacific, and Eurasia. Eventually, in addition to three operational satellites, two retired satellites would be maintained in reserve. Then, subsequent to the launch of DSP-14 in June 1989, a four-satellite operational constellation was established, with the creation of a European station. That constellation has been maintained since that time. Throughout the DSP program the data from the constellation has been augmented by data from infrared sensors carried by the two or three National Reconnaissance Office signals intelligence satellites operating in highly-elliptical orbit at any given time. Over the life of the program, the satellites have detected thousands of strategic and tactical missile launches, as well as French and Chinese atmospheric nuclear detonations-the later via its infrared sensor and the nuclear detonation detection sensors also carried on the spacecraft. (Note 6)

Since the first launch, the capabilities of DSP satellites have been enhanced. The first model of the satellite, which encompassed Flights 1-4, had an expected lifetime of 1.25 years (commonly exceeded) and 2000 detectors. The most recent model DSP-1, first orbited in 1989, had an expected lifetime of 5 years (also exceeded) and 6000 detectors-which provided far more accurate estimates of the coordinates associated with missile launches, an improvement intended to allow DSP to provide more precise information in the event of a nuclear exchange with the Soviet Union. The newer model also could detect infrared radiation from two different parts of the electromagnetic spectrum (making it harder to jam) as well as having both a below-the-horizon and above-the-horizon capability. (Document 26, Document 28)

In addition to the evolution in DSP capabilities, there has also been an evolution of missions and customers. As previously noted, DSP was originally established to detect strategic missiles launched against the United States, whether by the Soviet Union or China, and to detect nuclear detonations. The ability of DSP sensors to detect shorter-range offensive and surface-to-air missiles allowed it to detect and provide intelligence on missiles fired during regional conflicts-such as the Iran-Iraq war (1980-1988) as well as the 1991 Persian Gulf War. (Note 7, Document 24, Document 25)

In addition, the discovery that DSP's infrared sensor was detecting the flight of Soviet Backfire bombers, one version of which would be used to attack U.S. naval vessels in the event of war, led to the SLOW WALKER program. Its ability to detect the infrared signal reflecting off of spacecraft resulted in the FAST WALKER program. The ability to detect infrared events of sufficient intensity has also allowed DSP to provide data on aircraft crashes, ammunition dump explosions, and industrial processes. (Note 8) (Document 16a, Document 16b, Document 39)

A key element of the DSP system has been the ground stations used to control the satellites and receive the data they collect. Control over and processing of data from the first satellite stationed over Eurasia and its successors was the responsibility of the Overseas Ground Station (OGS) at Nurrungar, in the Australian Outback-the source of much political controversy. A second ground station at Buckley AFB in Colorado, the CONUS Ground Station (CGS), would control the Atlantic and Pacific satellites. Later on, to control the European satellite, the European Ground Station (EGS) was established at Kapaun, Germany. In addition to the large processing stations, a number of mobile ground terminals were built to allow DSP data to be received in the event of the destruction of any of the fixed stations. In addition, Joint Tactical Ground Stations (JTaGS) were deployed to Europe and Asia as part of the SLOW WALKER program. In 2000, the OGS and EGS were closed down, while relay stations were established at Pine Gap, Australia and Menwith Hill, United Kingdom to send the data back to CGS for processing. (Note 9) (Document 19, Document 20, Document 28).

While generations of DSP satellites demonstrated expanding capabilities, consideration of a follow-on system began as early as 1979. An initial concern, as noted above, was to improve DSP's ability to contribute data in the midst of a nuclear conflict with the Soviet Union-by making the satellites and ground stations more survivable and able to provide more detailed information, such as the precise coordinates of Soviet missile launches. In addition, since the creation of the Strategic Defense Initiative by President Ronald Reagan in March 1983, plans for future launch detection satellites needed to be integrated into plans for national missile defense.

Debates and disagreements over issues such as costs and technical requirements, within the executive branch and between the executive branch and Congress, resulted in a host of DSP follow-on programs having been proposed and then cancelled for over fifteen years. Thus, the Advanced Warning System (AWS), Boost Surveillance and Tracking System (BSTS), the Follow-On Early Warning System (FEWS), and Alert, Locate, and Report Missiles (ALARM) program, along with their acronyms, all came and went between 1979 and 1995. (Note 10) (Document 30a, Document 30b)

In 1995, the Air Force announced a new follow-on program-the Space-Based Infrared System (SBIRS). The program was to consist of four operational satellites in geostationary orbit, two infrared sensors on highly-elliptical orbiting National Reconnaissance Office satellites, and a SBIRS-Low segment that would be a crucial element of national missile defense. The low-earth orbiting portion of SBIRS has since been renamed the Space Tracking and Surveillance System (STSS), although its actual deployment is uncertain. Problems with the infrared sensors for the high-altitude satellites, schedule delays, and large increases in projected costs delayed the expected first launch of a SBIRS satellite, now expected in 2008. They also resulted in the decision to establish an Alternative Infrared Satellite System (AIRSS) program, should the decision be made not to procure more than the first two dedicated SBIRS satellites. (Note 11) (Document 39, Document 40, Document 41, Document 42) The performance of a SBIRS sensor on an NRO satellite launched in June 2006 produced optimism that the SBIRS program would continue beyond the first two satellites; and in June 2007, the Air Force decided to purchase a third geosynchronous SBIRS satellite, with an option to buy a fourth. In October 2007, new problems with the SBIRS effort were reported--although it still appeared the Air Force was going to purchase the third SBIRS spacecraft and begin investing in parts for a fourth. (Note 12)

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Document 1: J.A. Curcio and J.A. Sanderson, Naval Research Laboratory, NRL Report No. N-3327, Further Investigations of the Radiation from Rocket Motor Flames, July 26, 1948. Classification Unknown
Source: Freedom of Information Act

This paper examines the radiation emitted by the flames of rocket motors burning nitric acid and aniline as well as alcohol and oxygen. The objective of the reported research was to gather data that could be employed for a number of purposes-including optical detection tracking and homing on those targets.

Document 2: William W. Kellogg and Sidney Passman, Rand Corporation, RM-1572, Infrared Techniques Applied to the Detection and Interception of Intercontinental Ballistic Missiles, October 21, 1955. For Official Use Only
Source: Freedom of Information Act

This study was written by an expert on infrared technology (Passman) and an expert on high-altitude earth observation (Kellogg). They noted that a basic characteristic of an ICBM is the heat that it generates during takeoff and re-entry into the atmosphere and that hot metal is a good emitter of infrared radiation. They go on to examine alternative means for detecting missile launches from emitted radiation, observing the limitations of airborne detection and suggesting that satellite-based detection might be feasible.

Document 3: President's Science Advisory Committee, Report of the Early Warning Panel, March 13, 1959. Secret

Source: Dwight D. Eisenhower Library

By March 1959, when the PSAC Early Warning Panel met, the Missile Defense Alarm System (MIDAS) program--for the space-base detection of missile launches--had been established and was in the research and development phase. The report examines a number of alternative approaches to missile launch detection-the Ballistic Missile Early Warning System (BMEWS) ground-based radars, a fleet of U-2 aircraft equipped with infrared detection, as well as MIDAS. With respect to MIDAS, the panel concluded that construction of such a system was not yet justified.

Document 4: DDR&E Ad Hoc Group, Report on MIDAS (Draft), November 1, 1961. Secret
Source: National Archives and Records Administration

The DDR&E Ad Hoc Group, consisting of governmental and outside representatives, and chaired by Jack Ruina, head of the Advanced Research Projects Agency, was appointed by Secretary of Defense Robert McNamara to study the MIDAS program. The draft version of the report-that would be finalized by the end of the month-asserted that it was impossible to predict whether an operationally significant version of MIDAS could be developed within the following decade and examined the problems facing any attempt to produce an effective, operational system.

Document 5: Harold Brown, Memorandum for the Assistant Secretary of the Air Force (Research and Development), Subject: MIDAS System, June 25, 1962. Classification Unknown
Source: Freedom of Information Act

This memo was written at a time when there was still significant doubt within the Defense Department as to whether the MIDAS program could produce an operational system but strong belief in the program within the Air Force and its contractors. Director of Defense Research and Engineering Harold Brown warns the Air Force not to try to deploy an operational constellation under the cover of launching a series of research and development satellites.

Document 6: B.A. Schriever, Commander, Air Force Systems Command to Honorable Eugene M. Zuckert, Subject: DOD Program Change (4.4.040) on MIDAS (239A), August 13, 1962. Secret
Source: Freedom of Information Act

In this letter to the Secretary of the Air Force, General Bernard Schriever, commander of the Air Force Systems Command, conveyed his concern over Secretary of Defense McNamara's order to the Air Force, issued a week earlier, to drop all deployment plans for MIDAS and reorganize the program. He questioned the Defense Secretary's view on the declining future importance of early warning, emphasized the need to make a commitment to deploy a system, and disputed whether some of the alleged impediments to development of a system were truly problems.

Document 7
: Roswell L. Gilpatric, Memorandum for the Secretary of the Air Force, Subject: MIDAS, December 28, 1962. Secret
Source: Freedom of Information Act

On December 17, 1962, launch of the sixth MIDAS test satellite failed after the booster broke up and exploded shortly after launch. Eleven days later, Deputy Secretary of Defense Gilpatric informed the Air Force secretary Eugene Zucker that the Defense Department still considered it unwise to proceed with MIDAS as an operational system and that a number of alternatives might, collectively, provide the capability promised by the higher-risk MIDAS.

Document 8: Adam Yarmolinsky, Memorandum for Mr. Timothy J. Rearden, Special Assistant to the President, May 31, 1963 w/att: "A MIDAS Satellite Was Successfully Launched by Air Force on 9 May 1963 from Vandenberg AFB." Secret
Source: Freedom of Information Act

The launch of MIDAS 7 represented a turning point in the battle over whether space-based warning of missile launches was feasible. The satellite's infrared sensor was to be tested against the launch of Air Force and Navy missiles. Yarmolinsky's memo reports on the results from the first half of the satellite's forty-seven days in operation - and notes its sensor's successful detection of each launch.

Document 9: Robert E. McClellan, Space and Missile Systems Office, History of the Space Systems Division, July - December 1965, October 1968 (excerpt) Secret
Source: Freedom of Information Act

Despite the successful detections in 1963, MIDAS did not evolve into an operational program. By 1965, it had been designated Program 461-in keeping with security procedures that intended to obscure the mission of each program. One component of the program, involving the detection of submarine-launched missiles was designated Program 266 in October 1965. This portion of the SAMSO history explains plans for the Research Test Series intended to help produce an operational space-based early warning system.

Document 10: Robert F. Piper, Space and Missile Systems Office, History of the Space and Missile Systems Organization, 1 July 1967 - 30 June 1969, Volume I, March 1970. (excerpt). Secret

Source: Freedom of Information Act

Developmental work on a space-based launch detection capability continued into1966 and 1967 under Program 461. Meanwhile, on November 1, 1966 the Air Force designated Program 949 as a follow-on to 461. This portion of a SAMSO history discusses the objectives of the new program, plans for further launches of developmental satellites, the sensors the satellites were to carry, and plans for an overseas ground station.

Document 11
: Air Force Space and Missile Systems Center, Synthesis of "Preliminary Analysis of the Project Hot Spot IR Signals," December 7, 1973 and "Applications of Infrared Tactical Surveillance," May 29, 1975. Unclassified

Source: Freedom of Information Act

While the DSP satellites were developed for the purpose of detecting Soviet strategic missile launches, government personnel and contractors involved in the program would soon discover that the infrared sensor could also detect a number of other events of interest - including the launch of shorter-range missiles such as the Scud - a capability that would be of great value in the 1991 Persian Gulf War. This synthesis describes the effort made, at the Australian ground station, during the 1973 Yom Kippur War to monitor Egyptian Scud launches employing the DSP satellite located over the Horn of Africa.

Document 12: William G. Hyland to Helmut Sonnenfeldt, December 13, 1975. Secret
Source: Freedom of Information Act

On five occasions in October and November 1975, a DSP satellite (DSP-E) picked up intense infrared returns. On one instance the illumination lasted for more than four hours. One fear was that the satellite had been the target of Soviet lasers in an attempt to test the Soviet ability to "blind" the U.S. reconnaissance and surveillance satellites. This memo to an aide to Secretary of State Henry Kissinger provides background on the events and possible explanations. Ultimately, it was concluded that the most likely source of the signals were pipeline fires.

Document 13: Ellis E. Lapin, "Surveillance by Satellite," Journal of Defense Research, 8, 2 (Summer 1976), Secret

Source: Freedom of Information Act

Written by an individual who was involved in the DSP program for several decades, and published in a classified journal, this article provides technical details on the operation of the infrared sensor, the data reduction process, the types of data that can be produced by the satellite's infrared and nuclear detonation detection sensors, the accomplishments of the program since the first DSP launch in November 1970-which included the detection of gas fires, midair collisions, large fires, and surface-to-air missile activity.

Document 14
: HQ ADCOM to HQ USAF, Subject: Knowledge of the DSP System, October 10, 1980. Classification Unknown
Source: Freedom of Information Act

The issue of how well the Soviet Union understood the capabilities of U.S. reconnaissance and surveillance satellites was one that continually concerned the operators of those systems. This message is an attempt to provide some answers with regard to DSP.

Document 15: HQ ADCOM to HQ USAF, Subject: Flight 9 Operational Status, April 14, 1981. Classification Unknown

Source: Freedom of Information Act

The ninth DSP satellite was placed into orbit on March 16, 1981 and stationed over the Atlantic. Two weeks later President Ronald Reagan was wounded during an assassination attempt. This memo, from the Aerospace Defense Command, noted problems with the satellite and that it had generated false missile launch warnings on two occasions-on April 5 and 13. The later false reports "could have resulted in unacceptable posturing of SAC [Strategic Air Command] forces," according to the memo.

Document 16a: HQ SPACECOM to HQ USAF, Subj: Navy SLOW WALKER Support, May 9, 1983
Document 16b: D.L. Ritchey, "Backfire Supersonic Performance," Air Force Foreign Technology Bulletin, May 27, 1975

Source: Freedom of Information Act

The discovery of DSP's detection of the infrared emissions of Backfire aircraft assigned to Naval Aviation units flying on afterburner led the Navy to establish a program to access and exploit that data. The first document includes a rarely-seen reference to the SLOW WALKER program. The second provides information on the aircraft that was the main target of the program.

Document 17: Air Force Space Command, History of Space Command, ADCOM, January - December 1984, n.d. (excerpt). Classification Unknown
Source: Freedom of Information Act

This portion of the 1984 Air Force Space Command history describes the events related to the DSP constellation that year. It discusses movements of the satellites, problems with satellites, efforts made to fix the problems, and future initiatives to provide more capable sensors.

Document 18
: Air Force Space Command, History of Air Force Space Command, January - December 1987, n.d. (excerpt). Classification Unknown
Source: Freedom of Information Act

This portion of the 1987 Air Force Space Command history essentially covers two topics-developments with the satellite constellation that year as well as the controversy in Australia over the presence of the Overseas Ground Station at Nurrungar. The debate over the ground station's presence was heightened in 1987 due to the publication of Desmond Ball's A Base for Debate, which examined the ground station issue, which is discussed in detail in the history.

Document 19
: John Schenk, Air Force Space Command, Subject: European Ground Station (EGS), Contingency Planning, March 2, 1990. Classification Unknown

Source: Freedom of Information Act

In the 1980s, the DSP constellation was expanded from three operational satellites to four. In addition to adding a satellite to the space segment, a ground station was also added. In addition to the stations at Buckley AFB, Colorado and Nurrungar, Australia a station was added Kapaun, Germany (the European Ground Station). With the collapse of the East German government in 1989, the U.S. began to consider the possibility that a unified German government might wish that foreign military forces vacate German territory. This memo is one example of the contingency planning that was initiated.

Document 20: Col. Glenn P. Doss, Air Force Space Command, Subject: Deputy Commander (Woomera) Controversy, April 20, 1990. Secret

Controversy over the Australian ground station was not restricted to the debate over whether Australia should continue to provide a home for the station. There was also a disagreement between the United States and Australia over the powers of the Overseas Ground Station Deputy Commander--a post held by an Australian--when the American commander was not present. This memo is one of several that addressed the issue.

Document 21
: Air Force Space Command, History of Air Force Space Command, January - December 1990, n.d. Classification Not Available

Source: Freedom of Information Act

This extract from the 1990 history provides information on DSP operations as well as the issues involving the ground stations in Europe and Australia. With regard to the later it fills in much of what is redacted from the Doss memo (Document 20)

Document 22
: HQ USSPACECOM to HQ USCENTCOM, Subj: Potential for Tactical Application of Ballistic Missile Launch Notification, June 20, 1990. Secret
Source: Freedom of Information Act

From the very beginning of the DSP program it was clear that the satellite's sensors could detect tactical as well as strategic ballistic missiles-creating the possibility that DSP could be used to provide warning and other information to commanders in the field. With the end of the Cold War it was easier for theater commanders to request DSP support. This memo responds to a request from the U.S. Central Command for such support. It provides information on U.S. Space Command's creation of a system for the transmission of DSP data concerning tactical missile launches, as well as on the data that DSP is capable of providing.

Document 23
: HQ USSPACECOM, Memorandum for Record, "DSP Tactical Support," circa March 1991. Secret
Source: Freedom of Information Act

This memorandum recounts a meeting at U.S. Space Command headquarters to resolve issues concerning the access to DSP and other technical data, mutual support of tactical warning efforts, warning of strategic attack versus warning of theater missile attack, and the use of DSP to support specific service programs.

Document 24: Air Force Space Systems Division, DSP Desert Storm Summary Briefing, June 1991. Secret
Source: Freedom of Information Act

During the 1991 Persian Gulf War DSP played a key role in providing warning of Iraqi Scud missile launches (of which there 88)-whose targets were in Bahrain, Israel, and Saudi Arabia. This heavily redacted briefing provides some details of DSP capabilities and performance during the war- including why DSP failed to provide warning of the Scud that fragmented above Dhahran and whose warhead fell onto a warehouse that was housing American soldiers, killing 28 and wounding about 100.

Document 25: United States Space Command, United States Space Command Operations Desert Shield and Desert Storm Assessment, January 1992. (extract) Secret
Source: Freedom of Information Act

The full assessment covers the contribution of a variety of space systems to the operations that first halted Iraq's advance and then forced the retreat of Iraqi forces from Kuwait. The extract reprinted here concerns the contribution of the DSP satellites.

Document 26: Col. John Kidd and 1 Lt. Holly Caldwell, AIAA 92-1518, DSP Support to a Changing World, AIAA Space Programs and Technologies Conference, March 24-27, 1992, Huntsville, Ala. Unclassified
Source: Freedom of Information Act

This briefing, given by the DSP program director, provides a history of the DSP program-including such subjects as the collection and processing of data by the satellite, improvements in DSP capabilities, DSP ground stations, and the evolving missile threat.

Document 27: Harry N. Waldron, History of the Space and Missile Systems Center, October 1994 - September 1997, Volume I. March 2002. (excerpt). For Official Use Only

Source: Freedom of Information Act

This extract from the SMSC history covers both past and current DSP operations and capabilities as well as plans for the follow-on system-the Space-Based Infrared System (SBIRS). Specific topics discussed include satellite capabilities, ground stations, use of DSP for tactical warning, and envisioned SBIRS capabilities.

Document 28: Space Based Infrared Systems (SBIRS) System Program Office, Defense Support Program (DSP): A Pictorial Chronology 1970-1998, n.d. Unclassified
Source: Air Force Public Affairs

This booklet was prepared for a celebration of the Defense Support Program. It provides a breakdown of different DSP "models" and their capabilities, DSP program directors in the government and industry, a launch history, the phases of the program, DSP use in Operation Desert Storm, and information on DSP ground stations.

Document 29: General Accounting Office, Case Study of the Air Force Advanced Warning System, July 31, 1986. Unclassified

Source: General Accounting Office

Even before DSP had completed its first decade of operations, thought was being given to a follow-on system - particularly one that would be more survivable in the event of an actual war with the Soviet Union. This document provides a history of one of the early proposed follow-ons-the Advanced Warning System.

Document 30a: Assistant Secretary of Defense C3I, Report to the Congress on the Follow-On Early Warning System, April 15, 1991. Secret
Document 30b: Memorandum for Assistant Secretary of Defense (Command, Control, Communications & Intelligence), Subject: Follow-On Early Warning System, November 18, 1991. Secret w/att: Integrated Program Assessment for the Follow-On Early Warning System

Source: Freedom of Information Act

The first report provided Congress with information, redacted from the declassified version, on DoD's view on the need for an improved system, DSP performance in Desert Storm, and the objectives on the Follow-On Early Warning System (FEWS)-as the planned successor to the DSP system was known at the time. The remaining portion of the memo provides background, an explanation of why the AWS was cancelled, the impact of the new system on DSP ground stations, and acquisition plans. The second memo and attached report focuses on the benefits of FEWS, the cost drivers and tradeoffs, and risk assessment and risk reduction plans.

Document 31: General Accounting Office, Early Warning Satellites: Funding for Follow-On System is Premature, November 1991. Unclassified
Source: General Accounting Office

Despite DoD's support for FEWS, the General Accounting Office was skeptical, as they explained in this report, that funding of satellite development was currently justified. It examines some of the history of the consideration of DSP follow-on programs, and some possible alternatives to FEWS.

Document 32
: Maj. Gen. Garry Schnelzer, AFPEO/SP, Air Force Space Sensor Study, April 12, 1993. Classification Unknown

Source: Freedom of Information Act

The cancellation of AWS and then criticism of FEWS, was part of what would be a prolonged search for a follow-on system. A major study in the search process was conducted by the Air Force Program Executive Officer for Space. The study examined the capabilities and costs of a number of alternative systems - both in geosynchronous as well as low-altitude orbit - that might be used for the missile launch detection mission.

Document 33: Guido W. Aru and Carl T. Lunde, Aerospace Corporation, DSP-II: "Preserving the Air Force's Options," Executive Overview, April 23, 1993. For Official Use Only

Source: Freedom of Information Act

The Schnelzer study recommended continuation of the FEWS program-a recommendation that was popular in the Air Force and with the U.S. Space Command. There were dissenters-both in the Aerospace Corporation (which provided technical support to the Air Force and National Reconnaissance Office) and the Space Systems Division of the Air Force Systems Command.

This executive overview summarizes the results of a 500-page study, which questioned some of the requirements established for a follow-on to DSP (largely on the grounds that they were relics of the Cold War) and proposed an alternative that the authors believed would satisfy reasonable launch detection requirements at far less cost.

Document 34: Letter, Charles Horner, CINC, US Space Command, to Pete Aldridge, President, Aerospace Corporation, May 24, 1993. Unclassified
Source: Freedom of Information Act

Upon learning of the contents of the Aru and Lunde study (Document 30) U.S. Space Command commander-in-chief Charles Horner sent this hand-written note to the Aerospace Corporation's president expressing his anger at the report's contents.

Document 35: Col. Joe Bailey, System Program Director, Space-Based Early Warning Systems, "Point Paper on DSP-II TOR," May 24, 1993. For Official Use Only
Source: Freedom of Information Act

This point paper provides a concise background, overview, and critique of the Aru and Lunde DSP-II report (Document 30), released under the name of the head of the director of Space-Based Early Warning Systems (responsible for both DSP and successor program) of the Air Force Space and Missile System Center. The critique focuses in part on the requirements not met by the proposed alternative to FEWS. Other criticisms involved the projected cost of the alternative as well as the tone of the report.

Document 36a: E.C. Aldridge Jr., President, Aerospace Corporation To General Charles A. Horner, Commander, Air Force Space Command, May 27, 1993. Unclassified
Source: Freedom of Information Act
Document 36b: E.C. Aldridge Jr., President, Aerospace Corporation, To General Charles A. Horner, June 22, 1993. Unclassified
Source: Freedom of Information Act

These two letters are responses by Aerospace Corporation president Aldridge to General Horner concerning the DSP-II study (Document 30) - the first only a few days after Horner's handwritten complaint of May 24 (Document 31). In his May 27 letter Aldridge states Aerospace "clearly understands ... that the FEWS capability is the only concept that satisfies the needs of the operational commander."

Document 37: Report of the Space-Based IR Sensors/Technical Support Group, October 1993. For Official Use Only
Source: Freedom of Information Act

While Aerospace Corporation analysts might not have been authorized to produce a report questioning the need for FEWS, a review group appointed by Under Secretary of Defense John Deutch was. The group was headed by Robert Everett of the MITRE Corporation. While the group did not support the DSP-II proposal, it also suggested an alternative to FEWS. The group's report examined the requirements associated with FEWS as well as capabilities that a follow-on system needed to have and what type of system would satisfy those requirements.

Document 38
: Guido William Aru, Statement before the House of Representatives Committee on Government Operations, Legislation and National Security Subcommittee, February 2, 1994. Unclassified
Source: House Committee on Government Operations

The controversy over the follow-on to DSP, which included charges that FEWS opponents were being intimidated, was one topic of early 1994 Congressional hearings on strategic satellite systems. In his testimony Guido Aru provided his view of the issues involved, the results of his research, as well as actions directed against him and his co-author.

Document 39
: Air Force Space Command, SBIRS Overview Brief Combat Air Force Commander's Conference 16-17 November 1998, November 16-17, 1998. Classification Unknown
Source: Freedom of Information Act

In 1995, the long process to find a successor to DSP appeared to have concluded with the approval of the Space-Based Infrared System (SBIRS) program. Among the topics covered by this briefing are SBIRS mission areas, the SBIRS constellation, the allocation of tasks to specific parts of the constellation, SBIRS connection to national missile defense, and DSP detections of aircraft explosions.

Document 40: General Accounting Office, Defense Acqusitions: Space-Based Infrared System-low at Risk of Missing Initial Deployment Date, February 2001. Unclassified
Source: General Accounting Office

In this report GAO specifies a number of reasons why it believes that the SBIRS-Low system might miss its initial deployment date--including the gap between the beginning of production and the availability of test results and the immaturity of key satellite technologies.

Document 41: General Accounting Office, GAO-04-48, Defense Acquisitions: Despite Restructuring SBIRS High Program Remains at Risk of Cost and Schedule Overruns, October 2003, Unclassified

Source: General Accounting Office

Despite the optimism generated by the selection of SBIRS as the DSP follow-on, problems emerged with the new sensors, which were intended to be more capable than those carried on DSP spacecraft. As result, projected costs increased substantially while the date when the first SBIRS would be launched kept receding. This General Accounting Office study provides a detailed examination of the problems experienced by the SBIRS program as well as an evaluation of remaining risks with regard to cost and schedule delays.

Document 42: Office of the Secretary of Defense, Report to the Defense and Intelligence Committees of the Congress of the United States on the Status of the Space Based Infrared System Program, March 2005. Unclassified
Source: Freedom of Information Act

This unclassified document, over fifty pages in length, provides a description of the SBIRS mission, technical difficulties, management adjustments, remaining areas of risk (with regard to the ground and space segments), and assessments of the confidence in cost and schedule projections.


1. Jeffrey T. Richelson, America's Space Sentinels: DSP Satellites and National Security (Lawrence, KS.: University Press of Kansas, 1999), pp. 8-9.

2. Ibid., p. 11; N.W. Watkins, "The MIDAS Project: Part I Strategic and Technical Origins and Political Evolution 1955-1963," Journal of the British Interplanetary Society 50, 1997, pp. 215-224.

3. Richelson, America's Space Sentinels, pp. 14-37.

4. Ibid., p. 45.

5. William Beecher, "U.S. Lofts Satellite for Spotting Attack by Soviet or China," New York Times, November 7, 1970, pp. 1,9.

6. Richelson, America's Space Sentinels, pp. 73-74, 129-130.

7. Ibid., p. 159; Department of Defense, Conduct of the Persian Gulf War: Final Report to Congress (Washington, D.C.: Department of Defense, 1992), p. 240.

8. Richelson, America's Space Sentinels, pp. 95-109.

9. Ibid., pp. 137-156; Desmond Ball, A Base for Debate: The US Satellite Station at Nurrungar (Sydney: Allen & Unwin Australia, 1987).

10. Richelson, America's Space Sentinels, pp. 177-221.

11. U.S. Air Force, Fact Sheet, "Space Based Infrared Systems," October 2006.

12. Amy Butler, "In Recovery," Aviation Week & Space Technology, June 4, 2007, pp. 24-26; "USAF Decides to Buy Third SBIRS High from Lockheed," Space News, June 25, 2007, p.3; Jeremy Singer, "For Troubled SBIRS Program, 3rd and 4th Craft Closely Tied," Space News, October 22, 2007, p. 4.

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