A survivable avionics system for space applications

This paper describes an advanced survivable avionics system for future manned or unmanned space missions. The basic element of such an avionics system is a Byzantine fault tolerant computer (FTC), which has already been developed at DASA-RI for operation in the Russian segment of the International Space Station Alpha (ISSA). The paper outlines the essential design elements of the FTC, especially the efficient realisation of the Byzantine protocol within the constraints of technical risk and cost. We describe a quadruplex redundant MIL 1553 bus system with a synchronised packet protocol as communication medium between the FTC and the peripheral sensors and actuators. To illustrate the generic approach applied in the FTC design this paper also describes a fault tolerant Propulsion Drive Electronic (PDE) as a redundant actuator subsystem. The PDE will be equipped with basic communication and control elements re-using the FTC design.