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U.S. Military Satellites
MIRROR: JPL's MSL - A Briefing on Worldwide Satellites
Commercial Satellite Summary
The following are civilian satellites which are being used for various purposes by the U.S. Military.
NASA's ACTS was Iaunched in 1993 on the space shuttle to demonstrate Ka-band communications and onboard switching equipment. Military use of the technology demonstration satellite included communications service to US Army troops deployed to Haiti in 1994.
NOSA operates GOES-8 and GOES-9. GOES-7 provides backup. Satellites hover at 22,300 miles altitude over the equator, monitoring storms and tracking their movements for short-term forecasting. Satellites are a new design that has improved spatial resolution and full-time operational soundings of the atmosphere.
Established in 1964 to own and operate a global constellation of communications satellites. Has 141 members and 24 operational safellites. Intelsat is in the process of restructuring into an intergovernmental treaty organization, which will continue to provide basic global satellite connectivity, and a commercial spin-off called INC, which will be given three to seven satellites for competitive services like broadcasting and data networking. The restructuring should be approved in early 1998 and implemented in the following months. US signatory to Intelsat is Comsat Corp. The US military uses the system for routine communicalions and to distribute the Armed Forces Radio and TV Services network and used is to set up a Very Small Aperture Terminal data network for field commanders is Bosnia in 1996.
Established in 1979 to own and operate satellites for mobile communications. Has 79 membzr-countries. Inmarsat is 10.5 percent owner of ICO Global Communications, which was spun off as a separate company in 1995 to develop a satellite system for global mobile telephone services. Inmarsat operates seven satellites, including the first three of the third-generation Inmarsat 3 series and one Inmarsat 2 satellite. Another three satellites serve as orbital spares. The spacecraft are sometimes used by military forces for peacetime mobile communications services. Inmarsat is prohibited by convention from being used for military purposes. Briefcase- and laptop-sized satellite telephone terminals are used to communicate through the satellites. Inmarsat use in Somalia and Bosnia included the transmission of medical data and supply orders.
US government's civilian remote sensing satellite system. Used in polar orbit since 1972. Carries a multispectral scanner able to operate at a resolution of 30 meters and provide images that can be computer enhanced to show deforestation, expanding deserts, crop blight, and other phenomena. Space Imaging EOSAT operates the aging Landoat 5. The government plans to launch a Landsat 7 satellite in 1998. Military use of Landsat imagery has included mapping and planning for tactical operations.
Two polar orbit satellites for long-term forecasting of weather, operated by NOAA. The satellites fly in a 450 nautical-mile orbit, carrying visible and infrared radiometry imaging sensors and ultraviolet sensors to map ozone levels in the atmosphere. Provide weather updates for all areas of the world every six hours to civil and military users.
Orbcomm Global L. P.'s first two satellites were launched in April 1995 and commercial service in the US and Canada began in February 1996. Orbcomm is a joint venture between Orbital Sciences Corp and Teleglobe of Canada. Orbcomm's satellite constellation will comprise 28 satellites, with an additional eight satellites to serve as ground spares or to be launched at a later date. Orbcomm worked with DoD in 1995 and 1996 to demonstrate the potential military use of the commercial system under the Joint lntetoperablity Warfighter Program. Today, DoD still possesses more than 100 Orbcomm units [presumably this means terminals capable of making use of Orbcomm birds - MILNET].
Orion provides commercial satellite based, rooftop-to-rooftop communications in support of the US Army Trojan program via its own satellite as part of the GE American Communications team. In addition, Orion provides communications through wholesalers to other DoD agency locations in the US and Europe. Rooftop-to-rooftop support is also provided to selected State Department overseas locations. Orion continues its support for the troops deployed to Bosnia via leased capacity to the Defense Information Systems Agency. Future plans include the launch and operation of two additional satellites covering the Asia-Pacific region, Latin America, the Middle East, and parts of Russia and Africa.
Remote sensing satellite system developed by the French space agency, CNES. Owned and operated by a commercial firm, SPOT Image S, A, of Toulouse. Two satellites produce images with resolution as fine as 10 meters and can be used for stereoscopic viewing for three-dimensional terrain modeling. SPOT 3 failed in November, and SPOT 1 was reactivated to augment SPOT 2. SPOT 4 is scheduled for launch is early 1998 and SPOT 5 in 2002. [U.S.] DoD is a large customer, purchasing the images for mission planning systems, terrain analysis, mapping, and humanitarian missions.
Update: SPOT's success has spawned a whole new wave of commercial imagery satelliltes. In fact, the third generation of these birds is readying for launch, with technology that only a decade was usually only available in top secret military birds. As might be expected, during a conflict in a particular region, the U.S. tends to buy exclusive rights to all imagery for those passes, making wartime a huge boon to commercial companies. Rumor has it that there is a veiled threat behind the offer, "you give us the imagery at a good price or we'll simply consider your bird a threat and take it out." Both Russia and the U.S. have proven ASAT capability, so it is not a idle threat, at least capability wise. Politically and legally, the ASAT solution is a big unknown.
NASA operates six TDRSS satellites to form a global network that allows low Earth orbiting spacecraft, such as the space shuttle, to communicate with a control center without an elaborate network of ground stations. The geostationary TDRSS, with its ground station at White Sands, N M - allows mission control in Houston, Tex - to maintain nearly constant contact with the shuttle. Other satellites using TDRSS include the Hubble Space Telescope, Compton Gamma Ray Observatory , Earth Radiation Budget Satellite, and military satellites. TDRSS satellites have been used since 1983. Three next-generation satellites are being built for use with the shuttle, the space station, and satellites. Hughes is the contractor for TDRSS H, I, and J. The first will be launched in July 1999.
Update: All the second generation birds are now on orbit.
From
Air Force Magazine 1,
August 1997, pg. 25
Updated: April 2002