ULTRA HIGH RELIABLE SPACECRAFT COMPUTER-SYSTEM DESIGN CONSIDERATIONS

The requirements for spacecraft computer system are: ultra high reliability, fault tolerance, weight, power, memory size, software support, throughput and recovery time. Improving any one of this parameters will have definite impact on other parameters. In this paper spacecraft microcomputer design considerations are presented. In the proposed spacecraft computer system, a simple hardware redundancy scheme Implementation Is discussed. Spacecraft computer will be used to handle all measurements and on board controlling of the system. Special design requirements for the spacecraft system are addressed to incorporate fault tolerant hardware and software aspects. The reliability of the spacecraft computer system Is evaluated by using Markov models. It covers all permanent faults which affect the spacecraft computer system reliability. The proposed spacecraft system reliability Is estimated based on different redundant configurations.