U.S. Military Satellites

More on Military Satellites
JPL's MSL - Briefing on Satellites (MILNET Mirror)

U.S. Military Satellites serve meterological, intelligence, navigation, and communications needs for the services. Civilians also are able to enjoy the benefits of the military technology however, as meterological and navigational systems are made available to civilian distribution authorities as well. For example DMSP data is available through National Oceanographic and Atmospheric Administration (NOAA) and Global Positioning System (GPS) data is available at a slightly less resolution to anyone with a commerical grade GPS receiver.

U.S. intelligence satellites fall into several basic categories (See also: collection)

In the early years of military satellites, the most common sensors were of the PHOTOINT variety, with infrared and SIGINT satellites following very quickly. Today the watchword for overhead recon is "real time". This literally means the gathering of data from the satellite and transmittal to the ground station and the "observers" on the ground, all as it happens. This being a much desired upgrade over the early versions of recon satellites which spit out film packages or recording packages on a parachute each of which had to be recovered in order to get the data you desired. Also of concern today are the launch vehicles for satellites especially since the Challenger explosion.

U.S. satellites today serve one of three combinations of basic mission in terms of intelligence gathering:

  1. Dedicated : Primary mission is to gather overhead reconaissance
  2. Collateral: Military Satellite with a primary mission is other than space surveillance but either there is a second set of sensors on board or the primary sensor can be used for overhead reconaissance.
  3. Contributing: Non-military satellites with a means for providing military or intelligence quality overhead surveillance as a second or lower priority. Example: SPOT and its uses by the U.S. Military.

Satellite Programs

There have been a number of distinct satellite programs in the public knowlege:


Richelson first mentioned the Rhyolite/Aquacade series, and a web site in Denmark describes the satellites:
"The Rhyolite (later renamed to Aquacade, when the former name became public) are geostationary signals intelligence satellites. Their purpose was to intercept communications transmissions, especially line-of-sight microwave links and missile telemetry interception, from the Soviet Union and China. Unlike the Canyon SIGINT crafts, they were positioned in geostationary orbit.

The Rhyolite satellites were also known as Program 720 and Program 472. They were succeeded by the Magnum / Orion series." 4  [Spelling corrections by MILNET]

FAS describes the series:
"The geostationary SIGINT constellation consists of three or four satellites. The first generation of these satellites, known as Rhyolite, were launched in the early 1970s, and had a receiving antenna with a diameter of over ten meters. The next generation of these satellites, known as Chalet or Vortex, were first orbited in the late 1970's, and had an antenna with a diameter of several tens of meters. The most recent models, known as Magnum, were first launched in the mid-1980s, and have a very large deployable antennae with a diameter of approximately 100 meters. Satellites with an even larger antenna are currently under development. Increasing the diameter of the antennae of these satellites makes it possible to detect lower power transmissions, as well as to determine the position of a transmitter with increased precision." 5

The list below shows a simplified view of verifiable satellites and missions: 

Satellite          Number  Mission                                        
DMSP                 4     Meteorlogical, Xray, IR
DSCS II              3     SHF Communications, static coverage, all U.S. military
DSCS III             8     SHF Communications, flexibile coverage, all U.S. military 
DSP                 17     Launch-Nuclear detonation detect (? in service). 
FLTSATCOM            5     UHF - U.S. Navy and U.S. Air Force
MILSTAR              2     EHF Communications for all U.S. Military
NAVSTAR GPS         24     Global Positioning Navigation, Time/Velocity/Position
UHF Follow On       10     UHF/EHF (from UFO-4 on) replacing FLTSATCOM

NATO satellites      ?     Various missions, launched and maintained by U.S.,
                           data is presumably shared between sponsoring 
                           nation and the U.S.

Further Reading

For additional information on this and other intelligence topics, see the MILNET Bibliography for

1 The U.S. Intelligence Community , by Jeffrey T. Richelson, and

2 Deep Black , by William E. Burrows.

3 ARCO Illustrated Guide to Spy Planes , Bill Gunston

4  Rhyolite/Aquacade, Gunter's Space Page, Gunter Dirk Krebs, 1/4/2005

5  SIGINT Overview, The Federation of American Scientists, 3/9/1997

6  Pentagon Pursues New Multibillion Dollar Spy Satellite System, A.P., Fox News, 12/01/2007

milnet@milnet.com