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