An environment for incremental development of distributed extensible asynchronous real-time systems

Incremental, parallel development of distributed real-time systems is difficult. Architectural techniques and software tools developed at the Jet Propulsion Laboratory's (JPL's) Flight System Testbed (FST) make feasible the integration of complex systems in various stages of development. In particular, two techniques are used: a strict layering architecture for organization of independent subsystems, and a distributed, low-overhead, asynchronous messaging system. These techniques were developed in a few user-months and have proven their usefulness in a spacecraft integration test and simulation environment.