But the military's needs far outstrip the Defense Department's own satellite resources, leaving the military to rely heavily on a number of civilian and international systems. That reliance has raised concerns among some officials both about continued military access to international systems and the potential vulnerability of dual-use systems in the event of military conflict. Some of the major civilian satellites in military use include the following, as reported in the Air Force Association's 1997 space almanac:
- Advanced Communications Technology Satellite (ACTS). When the Army deployed troops to Haiti in 1994, military communications systems were overburdened with multiple deployments so the service turned to ACTS, launched by NASA a year earlier to demonstrate Kaband communications and onboard switching equipment.
- Geostationary Operational Environmental Satellite (GOES). The Defense Department relies on these advanced weather satellites operated by the National Oceanic and Atmospheric Administration.
- International Telecommunications Satellite Organization (Intelsat). Established 34 years ago to own and operate a global constellation of communications satellites, Intelsat is being restructured as an intergovernmental treaty organization with a commercial spin-off called INC. The military uses the system for routine communications and to set up a data network for field commanders in Bosnia.
- International Maritime Satellite (Inmarsat). Seventy-nine member nations participate in the mobile communications satellite system established in 1979. Prohibited by convention from military use, the system nonetheless has been used for peacetime operations, including those in Somalia and Bosnia.
- Landsat. The military has used this civilian remote sensing satellite system for mapping and planning tactical operations.
- Satellite Pour L'Observation de la Terre (SPOT). The Defense Department is a big customer of this remote sensing satellite system developed by the French space agency, CNES, and owned and operated by the commercial firm SPOT Image S.A. of Toulouse. DoD purchases images for mission planning, terrain analysis, mapping and humanitarian missions.
- Orbcomm. A joint venture between Orbital Sciences Corp. and Teleglobe of Canada, Orbcomm's satellite constellation demonstrated for DoD the potential military use of the commercial system under the Joint Interoperability Warfighter Program. DoD has more than 100 Orbcomm units.
- Orion Network Systems. Orion provides communications among DoD agencies in Europe and the United States and among selected State Department locations.
- NOAA-12 and NOAA-14. These polar orbit satellites operated by the National Oceanic and Atmospheric Administration provide civil and military users with long-term forecasting and worldwide weather updates every six hours.