Artist impression of early Samos F-2 signals intelligence satellite.
Early American signals intelligence satellites
by Dwayne Day
Tales of espionage are filled with lanky men in trenchcoats walking through cold Berlin streets at the height of the Cold War. But the most important intelligence—in terms of volume and reliability—was gathered by reconnaissance satellites far overhead. These satellites were precise, they collected vast amounts of information, and unlike spies, they did not forget, embellish, lie, or go rogue. Photographic reconnaissance satellites like CORONA, GAMBIT, HEXAGON, and KENNEN were in many ways the most prolific spooks. But they were also accompanied by other satellites, signals intelligence, or SIGINT, satellites that listened for the electronic whispers of radars and radios, engaged in a high-tech war of electrons against an enemy that could vanish and emerge at will.
During the Cold War the United States intelligence community gathered signals intelligence from the Soviet Union via a variety of means. These included ground stations, cable-tapping and bugging operations, airborne platforms such as the RC-135 Rivet Joint and RB-47 Stratojet, and signals intelligence satellites. Any history of SIGINT satellite operations during the Cold War is going to be limited in scope because much of the story remains classified, and unlike the reconnaissance photographs, signals intelligence is an arcane and esoteric subject.
|What the history reveals is that SIGINT satellite operations by the United States during the 1960s were far more complex than independent observers ever imagined.|
In 1998, the National Reconnaissance Office (NRO), which develops and operates intelligence satellites, declassified the first signals intelligence satellite named GRAB, which was launched in April 1960. GRAB was developed by the Naval Research Laboratory (NSL) in Washington, DC, and part of the NRL was later subsumed as a component of the super-secret NRO. In 2007 the NRO declassified the follow-on to GRAB, named POPPY. But both of these declassification actions were limited, leaving out many major details such as the appearance of some of the satellites, the variety and types of signals they collected, and even how long they operated. The NRO released further details in dribs and drabs over the next several years, but GRAB and POPPY operations remained shrouded in a certain amount of mystery and confusion. But while the GRAB and POPPY revelations were significant, the reality was that they represented only a small part of the story. Throughout the 1960s the NRO operated many other SIGINT satellites and platforms, most developed by the US Air Force, and these remained shrouded in secrecy. Until now.
Starting last year, the NRO declassified portions of its official history of signals intelligence satellites. Titled The SIGINT Satellite Story and written in 1994, it was produced by four authors: Major General David D. Bradburn, US Air Force (retired); Colonel John O. Copley, US Air Force (retired); Raymond B. Potts, National Security Agency (retired); and one other retired National Security Agency employee whose identity remains classified. One chapter of the history tells the story of the GRAB and POPPY satellites. Two chapters in The SIGINT Satellite Story explain much of the history of the other low Earth orbit satellites operated by the NRO during the Cold War. What the history reveals is that SIGINT satellite operations by the United States during the 1960s were far more complex than independent observers ever imagined, and the NRO operated satellites with names like MULTIGROUP and STRAWMAN, and numerous SIGINT payloads with names like NEW JERSEY, DONKEY, and OPPORKNOCKITY. Although other parts of this effort remain classified, over the years details have also emerged about a class of small SIGINT satellites with names like FARRAH, RAQUEL, and URSULA.
Agena spacecraft being prepared for launch in August 1961. This mission carried both a TAKI payload for intercepting Soviet TALL KING air surveillance radar emissions and a SOCTOP payload for determining if the vehicle was being tracked or the Soviets were attempting to take control of it. The payloads may have been mounted under the gray box structure on the aft rack of the Agena. The CORONA photo-reconnaissance payload has not yet been attached to the front of the Agena. (credit: Peter Hunter)
The wizard war in orbit (part 2)
Black black boxes
by Dwayne Day
By fall 1959, a number of CORONA photo-reconnaissance spacecraft had already been launched under cover of the Discoverer program, but none had operated successfully. Program officials became concerned that the Agena spacecraft that carried CORONA might be vulnerable to tracking by Soviet radars, or possibly even deliberate electronic interference. They did not think this explained CORONA’s early string of failures, but it was a possibility they worried about. At the time, Harold Willis was working in the Office of ELINT located at CIA Headquarters when CORONA officials briefed him about their program and told him about their concerns.
Willis also learned about the Samos Subsystem F signals intelligence satellite program, which at the time consisted of the F-1 and F-2 payloads. The former was a relatively small payload that would fly attached to a Samos photo-reconnaissance satellite and the latter a larger and more capable payload that would occupy the front end of an Agena spacecraft. Although the specialized F-2 satellite might be able to detect Soviet transmissions or interference, it was then scheduled to fly years after CORONA became operational. Willis thought that the Soviet threat to CORONA and other military satellites could develop sooner and they should not wait for the Samos signals intelligence satellites to provide data. He was not simply worried about problems over the Soviet Union but even far out over the oceans: the Soviets also had ships and trawlers with radomes, and nobody knew what they were for.