Many space systems that we rely on when conducting everyday activities – including global navigation and positioning, weather forecasting, and communications – were originally developed for military use. Today, systems such as GPS provide essential functions to both civilian and military users, and in some cases are integrated with critical civilian infrastructure on Earth.
Such passive use of space assets in support of terrestrial military capabilities has long been considered peaceful. Military capabilities such as missile warning and national technical means of verification for arms control can help to provide strategic stability. However, dependence on military space systems, the vulnerability of these systems to a range of interference and negation capabilities, and the extension of strategic relationships and alliances to include the use of space-based assets in defence activities all raise the prospect that conflict on Earth will spill into space.
Types of Military Satellites
Military satellites have historically been used to provide data and services in support of terrestrial military activities. The primary functions of military satellites include:
- The provision of dedicated and often more secure strategic and real-time tactical communications capabilities to armed forces. Some satellites transmit data from other types of satellites back to Earth. Global satellite communications require an extensive network of satellites; few states have such dedicated military capability.
- Reconnaissance – capturing images of Earth with optical, radar, infra- red, and multi-and-hyperspectral sensors.
- Navigation and weapons targeting made possible with Global Navigation Satellite Systems (GNSS) such as GPS that provide precise global positioning data.
- Weather information and forecasting. With a few exceptions, most states now rely on civilian capabilities for this service.
- Signals intelligence (SIGINT), which is used to intercept and collect communications, radar, and other electronic signals (ELINT).
Who Operates Military Satellites?
The number of states that own and operate satellites dedicated to military functions is growing. As of July 2020, the satellite database of the Union of Concerned Scientists indicates that 29 states operate satellites with dedicated military or dual-use functions: Australia, Belgium, Brazil, Canada, Chile, China, Colombia, Denmark, Egypt, France, Germany, Greece, India, Iran, Israel, Italy, Japan, Luxembourg, Mexico, Qatar, Russia, South Africa, South Korea, Spain, Sweden, Turkey, United Arab Emirates, United Kingdom, United States. Most dedicated military satellites are operated by the United States (204), China (114), and Russia (104).