Early History

During World War II, lookouts aboard surfaced German submarines used handheld crystal-video radar receivers called ATHOS to detect pulses emitted by search radars on Allied warships and aircraft This type of receiver consisted of a tuning coil and capacitor to select the approximate radio frequency to be received; a crystal diode, usually of silicon, that acted as a one-way gate, or rectifier, and produced an audible sound; and a simple amplifier that broadcast the “detected” sounds over a headset or loudspeaker. After the war, this same technology was adopted and applied in the direction-finding systems of American warships and airplanes because of its simplicity, small size, and “wideopen” frequency-detection characteristics.

Sputnik I, the world’s first artificial satellite, inaugurated the Space Age on 4 October 1957. On 22 June 1960, another satellite, built by the US Naval Research Laboratory and containing an ATHOS-type receiver in low Earth orbit, became the first US military satellite designed to intercept signals from Soviet radars. This marked the beginning of a concerted campaign by the United States to develop satellites for signals intelligence (SIGINT) to listen to and record radar, communications, and telemetry signals coming from the Soviet Union, and to transmit that data to US intelligence agencies. 1

The SIGINT satellite history is part of the larger story of the use of reconnaissance satellites by the United States to provide crucial early warning of a Soviet surprise attack on this country, and to attempt to solve the larger riddle of the Cold War—what was the Soviet Union up to? Predicting the quick appearance of – long-range rockets armed with nuclear bombs, Arthur C. Clarke described the potential strategic nuclear dilemma as early as 1946: “A country’s armed forces can no longer defend it; the most they can promise is the’ destruction of the attacker.” 2

The problem foreseen by Clarke became a reality. Attacked with nuclear weapons, a country would have no time to mobilize its forces, much less to build new weapons for them. For the next 45 years, the secrecy of the Soviets, their explicit threats to the non-Communist world, and their eventual possession of nuclear weapons and intercontinental delivery systems occupied the attention of every US President and dominated every major foreign and domestic decision made by the United States. For American leaders, the central question became: How do we prevent the Soviets from mounting a surprise nuclear attack against-us? Although Clarke had described both the nuclear dilemma and the potentials of satellites by 1946, his writing ‘remained obscure and was not influential at the time.

Within the United States, a scientific and engineering team at the RAND Corporation contributed to the determination that an Earth-orbiting satellite could be built that would have utility for reconnaissance. The RAND work culminated with a 1954 report, Project FEED BACK. that provided the rationale and the engineering calculations that prompted the United States to proceed with reconnaissance satellite development programs. 3 On the basis of the RAND studies and its own in-house work, the US Air Force in 1955 issued contracts for development of military reconnaissance satellites. When the Soviets launched Sputnik I in October 1957, these projects were already in existence, awaiting only the additional impetus that the Space Age would provide.

After Sputnik, the Air Force reconnaissance satellite work, based in Los Angeles at the Air Force’s Western Development Division (WDD), was accelerated and placed under a succession of different management arrangements. It was placed first under the Advanced Research Projects Agency (ARPA), then under the Air Force Ballistic Missile Committee (AFBMC), 4  and finally, in late 1960 at Presidential direction, under direct management of the Secretary of the Air Force. This decisive move resulted in clean, short decision lines for these important projects. Within two years, by May 1962, this same central authority was extended to cover Navy and Central Intelligence Agency (CIA) satellite projects, when Under Secretary of the Air Force Joseph V. Charyk, reporting to the Secretary of Defense, became the first Director of the National Reconnaissance Office (NRO). The NRO would play a central, crucial role in satellite reconnaissance for the remainder of the Cold War.

1. History of the POPPY Satellite System, BYE-56105-78, pp. 1-3.

2. Clarke, Arthur C., RAF Quarterly, March 1946, pp. 61-69. Republished in John Wiley, Ascent to Orbit, 1984.

3. Davies. Merton E. and William R. Harris, RAND’s Role in the Evolution of Balloon and Satellite Observation Systems and Related US Space Technology, Santa Monica, CA: the RAND Corporation, 1988, pp. 57-58.

4. Martin comments, SIG1NT Satellite History peer review, March 1994.

NRO APPROVED FOR RELEASE 10 FEBRUARY 2016
Source: National Reconnaissance Office, The SIGINT Satellite Story