The objective of the Multi-Path Redundant Avionics Suite (MPRAS) program is the development of a set of avionic architectural modules which will be applicable to the family of launch vehicles required to support the Advanced Launch System (ALS). To enable ALS cost/performance requirements to be met, the MPRAS must support autonomy, maintenance, and testability capabilities which exceed those present in conventional launch vehicles. The multi-path redundant or fault tolerance characteristics of the MPRAS are necessary to offset a reduction in avionics reliability due to the increased complexity needed to support these new cost reduction and performance capabilities and to meet avionics reliability requirements which will provide cost-effective reductions in overall ALS recurring costs. A complex, real-time distributed computing system is needed to meet the ALS avionics system requirements. General Dynamics, Boeing Aerospace, and C.S. Draper Laboratory have proposed system architectures as candidates for the ALS MPRAS. The purpose of this document is to report the results of independent performance and reliability characterization and assessment analyses of each proposed candidate architecture and qualitative assessments of testability, maintainability, and fault tolerance mechanisms. These independent analyses were conducted as part of the MPRAS Part 2 program and were carried under NASA Langley Research Contract NAS1-17964, Task Assignment 28. Baker, Robert L. Unspecified Center ADVANCED LAUNCH SYSTEM (STS); AIRBORNE/SPACEBORNE COMPUTERS; ARCHITECTURE (COMPUTERS); AVIONICS; DESIGN ANALYSIS; FAULT TOLERANCE; REAL TIME OPERATION; REDUNDANCY; RELIABILITY ENGINEERING; SPACECRAFT DESIGN; SUPPORT SYSTEMS; COST REDUCTION; MAINTAINABILITY; RELIABILITY ANALYSIS...

The Advanced Information Processing System (AIPS) is a fault-tolerant distributed computer system architecture that was developed to meet the real time computational needs of advanced aerospace vehicles. One such vehicle is the Advanced Launch System (ALS) being developed jointly by NASA and the Department of Defense to launch heavy payloads into low earth orbit at one tenth the cost (per pound of payload) of the current launch vehicles. An avionics architecture that utilizes the AIPS hardware and software building blocks was synthesized for ALS. The AIPS for ALS architecture synthesis process starting with the ALS mission requirements and ending with an analysis of the candidate ALS avionics architecture is described. Lala, Jaynarayan H. and Harper, Richard E. and Jaskowiak, Kenneth R. and Rosch, Gene and Alger, Linda S. and Schor, Andrei L. Unspecified Center ADVANCED LAUNCH SYSTEM (STS); AIRBORNE/SPACEBORNE COMPUTERS; ARCHITECTURE (COMPUTERS); AVIONICS; DIGITAL COMPUTERS; DISTRIBUTED PROCESSING; FAULT TOLERANCE; INFORMATION SYSTEMS; COMPUTER SYSTEMS DESIGN; DESIGN ANALYSIS; HEAVY LIFT LAUNCH VEHICLES; LOW EARTH ORBITS; MISSION PLANNING; REAL TIME OPERATION...