Boundary monitoring of every emission — including secondary frequencies, beacon fields, and contingency profiles — surfaces covert use of out-of-band links.

Boundary monitoring at the spacecraft's external interface flags emissions consistent with auxiliary-port enablement and out-of-plan transponder routing.

Boundary monitoring on the bus/payload interface surfaces unauthorised content routed from host bus into payload communication channels.

Boundary monitoring at external entry points and mission-critical internal boundaries surfaces adversary staging activity within or against operator infrastructure.

Boundary monitoring at provider portals, ground-station file drops, and automation repos surfaces staged-payload activity prior to triggering.

Boundary monitoring on RF and network entry points is the operator-side mechanism that detects active probing of mission systems.