Satellites are spacecraft used for communications, navigation and timing, Earth observation, or scientific missions, together with their ground stations, control systems and radio links. Their security depends on more than the vehicle in orbit: mission software, supply chains, telemetry and command channels, and terrestrial networks are all part of the operational system. Availability and command integrity can be safety- or mission-critical, while some payloads handle sensitive communications or location data.
Material risks include unauthorized commands after compromise of a ground system, jamming or spoofing of radio signals, and vulnerabilities in onboard or ground software. Appropriate controls include authenticated and encrypted commands, strict separation of control networks, careful key management, signed and tested updates, and monitoring for abnormal telemetry or access. Operators also need vulnerability management and rehearsed recovery plans that account for limited patching opportunities, long communication delays, and the need to preserve safe operation if links or ground facilities are unavailable.