A system of systems is a mission built from multiple independent systems that work together to deliver one capability. In satellite operations, that may include the spacecraft, ground stations, command software, identity and key management, supplier tools, and monitoring services. Each part can function on its own, but the mission only works when they interact correctly.
This matters in cyber security because attackers usually target the weakest link in the chain, not the most visible asset. A flaw in authentication, remote access, telemetry handling, or a vendor connection can affect the whole mission, even if the satellite itself is hardened. Defenders use this concept to map dependencies, protect trust points, segment networks, and plan for compromise in one layer without losing control of the entire operation.