Real-time spacecraft simulation and hardware-in-the-loop testing

The integration of flight hardware with real-time simulations increases spacecraft attitude control systems (ACS) reliability by providing greater test coverage through end-to-end testing in a realistic test environment. The paper describes a laboratory environment for development and testing spacecraft ACS and components, with emphasis on the real-time software architecture using RT-Linux. The environment included real-time control and data acquisition applications on a network of RT-Linux computers, Matrix/sub X/ control system design automation tools for real-time simulation and hardware-in-the-loop testing, and special test equipment. Hard real-time tasks with periods of 60 microseconds to 1 second were implemented using RT-Linux with a rate monotonic scheduler. This facility is currently being used for end-to-end tests on the Odin spacecraft ACS flight hardware, and work is in progress to support ACS R&D and Canadian satellite missions.