Next generation space avionics: layered system implementation

Advances in electronics over the past decade have produced major improvements in the power and flexibility of computer systems. Unfortunately current avionics systems for space applications typically have not leveraged these COTS advantages. A decade ago, the state-of-the-art for avionics systems made a step change to the Integrated Modular Avionics (IMA) used in the Boeing 777. This next generation avionics architecture is not based upon traditional Byzantine redundancy structures, but on a truth-based scheme where each element knows when an internal failure occurs and removes itself from the system. IMA utilizes a lock-step microprocessor design that communicates to a COTS Backplane for input/output, and to a Virtual Backplane/spl trade/ (a reliable high-speed serial bus) for intra-system communication. The system functions are implemented using a time and space partitioned operating system. The entire system provides the simplicity of a simplex system, implements the highest level of reliability providing complete flexibility to reconfigure both software applications and hardware interfaces, allows for rapid prototyping using low-cost COTS hardware, and is easily expandable beyond the initial point implementation. As the only 5/sup th/ generation avionics architecture, the concepts incorporated into Honeywell's IMA are ideally suited to be the backbone of the next generation Space Exploration Program avionics architectures.