America’s Space Sentinels: DSP Satellites and National Security. By Jeffrey T. Richelson. Lawrence: University Press of Kansas, 1999. ISBN 0-7006-0942-3. Figures. Tables. Notes. Bibliographic Essay. Index. Pp. xix, 329. $35.00.
Although now more thana decade old, this book is still the state-of-the-art in knowledge about the development of the Defense Satellite Program (DSP). Truly one of the most innocuous code names ever devised for a critical military program, DSP arose in the earliest years of the space age as a means of detecting the launch of a rocket from anywhere in the world. With the development of ballistic missiles in the 1950s, for the first time in the history of the United States our two great oceans could not protect us from sustained attack and destruction.
To warn against a Soviet ballistic missile attack, and thereby to allow time for the launch of a counterattack, the Department of Defense sponsored the development of satellites ringing the globe that would use infrared photographic technology to detect missile launches. The theory behind the system was that the heat signature from the rocket blast would be detected by satellites in space and then show up on infrared scopes at military monitoring posts. Through this process the time and place of launch, as well as the missile trajectory, could be ascertained within seconds of launch.
It was a brilliant concept but it took years for it to come to fruition. The first effort, Project MIDAS, experienced numerous technical problems, but finally reached a turning point in 1963 when MIDAS 7 detected the first missile launch from space. MIDAS confirmed the concept, and the DSP program, with first launch in 1970, has provided early warning of missile launches ever since. Through 1997 eighteen DSP satellites had been placed in orbit through 1999, not all of them were operational of course at the same time.
Jeffrey T. Richelson’s history of this program, America’s Space Sentinels, is an especially important and welcome addition to the literature of the military space program. It provides as comprehensive an understanding of this effort as is possible in the current environment, using a wealth of declassified documents to piece together this program’s evolution from idea to implementation and operational life. It is, of course, not the final word on this subject because of still-classified materials that should one day be made available about DSP, but it represents a benchmark in the historiography.
Especially welcome is Richelson’s discussion of DSP’s employment in the post-cold war era. He provides an excellent overview of its use to detect Scud missile launches in the Gulf War of 1991. He also describes how it detected the test firing of a new Iranian missile in 1998 and its use in piecing together the details of airplane accidents, such as the September 1997 collision of American and German military aircraft off the Atlantic coast of Africa. He ends with a discussion of the follow-on missile launch detection program, the Space-Based Infrared System (SBIRS), which is due to come on line at the end of the century.
From the time when DSP served as the backbone of the nation’s strategic early warning system during the cold war through its continued use in the still very threatening climate of the 1990s to its replacement by a presumably more capable system, this book is an important contribution to the public’s understanding of space-based military systems. It should be required reading for all who are interested in the strategic defense of the United States in the nuclear era.