An Expert System for Conducting a Satellite Stationkeeping Maneuver

In this paper, we describe the development and capabilities of a prototype expert system that provides real-time spacecraft system analysis and command generation. At present, ESSOC, the Expert System for Satellite Orbit Control, is capable of performing the stationkeeping maneuver for a geostationary satellite. ESSOC guides the operator through the stationkeeping operation by recommending appropriate commands that reflect both the changing spacecraft condition and previous procedural action. Information regarding satellite status, which is continuously updated from satellite telemetry, is stored separately from procedural information, which remains constant. Three features of this project are noteworthy: first, we employed a structured method for rapid knowledge acquisition from the domain experts; second, the ESSOC development effort involves a blending of simulation and expert systems technology; third, the system responds in real time, permitting timely action critical to satellite welfare.