SA-8(15) - Security and Privacy Engineering Principles | Predicate Permission

Implement the security design principle of predicate permission in [Assignment: organization-defined systems or system components].


ID: SA-8(15)
Enhancement of : SA-8

Space Segment Guidance

Predicate permission introduces contextual checks before command execution. For example, a thruster-fire request might require the propulsion subsystem to report nominal pressures and the attitude control loop to confirm safe pointing. Encode predicates in a hardened rule engine that the flight computer calls automatically and stores the outcome in telemetry so controllers can verify which preconditions passed. This mechanism blocks unsafe commands without relying on operator vigilance alone.