SAT-CIRCA: Verifiable Real-Time Autonomy for Satellites

SIFT proposes to build SAT-CIRCA: an integrated, verifiable architecture for real-time satellite response planning and execution. In previous research, we have developed the Cooperative Intelligent Real-time Control Architecture (CIRCA), including a planning system uniquely capable of reasoning about adversarial domains, building reactive real-time plans for those domains, and using formal verification techniques to prove that its plans will guarantee system safety while also making best efforts to achieve mission goals. In Phase 1, we have demonstrated the feasibility of integrating the CIRCA reaction planning system with NASA's most advanced technologies for verifiable onboard plan execution, the Plan Execution Interchange Language (PLEXIL) and the Universal Executive (UE). Together, PLEXIL and the UE provide a platform that will implement CIRCA's guarantees. SAT-CIRCA will use CIRCA's reaction planner to build plans in PLEXIL and execute them using the UE, thus guaranteeing that the UE will enforce the guarantees that CIRCA planned. SAT-CIRCA will be the first onboard autonomous satellite system capable of reasoning about its hazardous environment and guaranteeing to keep the system safe if at all possible.