Released Records

Index, Declassified SIGINT Phase II Records - November 29, 2017


NRO Historian's Note

Public Release of SIGINT Phase II Records

Since 1946, the United States had earnestly sought reconnaissance capability from space to protect and enhance the nation's security. The collection of signals intelligence (SIGINT) from space has been a critical component of this effort. This release of documents provides new insight into the essential need for SIGINT collection from space.

Following the release of a 1946 report calling for investment into satellites for national defense purposes, the RAND Corporation tenaciously researched and advocated space-based reconnaissance systems. The effort continued until RAND's publication of its seminal 1954 report, Project Feedback, which provided highly evolved concepts for reconnaissance satellites. RAND advocated for the more well-known photoreconnaissance satellites. Since public acknowledgement of Project Feedback, less attention has been given to signals collection capabilities called for in the report, and less has been publically disclosed about those capabilities. This release of documents is a major step forward in both revealing previously classified information on early satellite SIGINT collection and rebalancing understanding about the nature of the United States full national reconnaissance program.

Project Feedback led the United States to establish a program eventually known as Weapons System 117L (WS-117L) which included the SAMOS program. The United States Air Force (USAF) was responsible for overseeing the program and told the public that its primary purpose was to collect imagery from space and also provide early warning capability in the event of a Soviet missile attack. The public was not told of a secondary and originally less important mission, to collect signals intelligence from space. This was in keeping with the secrecy surrounding intelligence collection where signals collection efforts remained more cloaked than imagery collection efforts.

By the early 1960's, the Department of Defense cancelled the imagery collection efforts under the SAMOS program in favor of more promising programs at the time-namely CORONA and GAMBIT photoreconnaissance satellite programs. However, the efforts to collect SIGINT envisioned under the SAMOS program continued apace. Originally designed as secondary payloads to the primary imagery systems, the signals collection payloads evolved as the primary sensors that emerged from the remnants of the SAMOS program. The SIGINT collection satellites were renamed after the closure of the SAMOS imagery efforts, but they very much carried the SAMOS legacy forward-although covertly and long unacknowledged to the public.

The SIGINT records in this release provide insight and details about these early successes in SIGINT collection from space. This collection of documents joins the previous releases on the other signals collection satellites including GRAB, POPPY, and AFTRACK sensors. They were carried on the Agena control vehicle that the NRO used for CORONA and GAMBIT programs. This release reveals how signals collection grew from experimental payloads to providing key strategic and later tactical intelligence for the United States. Moreover, this release also sheds light onto how the United States focused on integrating reconnaissance satellite vehicles to serve as what might be called today a force multiplier. The integration amplified satellite collection capabilities and contributions.

Finally, in this collection of documents there are frequent references to the P-11 program and passenger payload satellites. These references provide clear hints as to future releases of documents on the nation's early signals collection satellites. We look forward to revealing more about these satellites, each of which have their own unique capabilities and histories.

Ultimately these releases are critical to help American citizens understand the nature and use of satellites for reconnaissance collection purposes-that they were launched to reveal insight into the monolithic capabilities of the Soviet Union. Those insights proved necessary to counter the Soviet threat and to secure the peaceful conclusion of the cold war.

James Outzen, Ph.D.
NRO Historian
Chief, Historical Documentation & Research
Center for the Study of National Reconnaissance