Fault-tolerant computer for the Automated Transfer Vehicle

Matra Marconi Space is developing their fourth generation fault-tolerant majority voting computers for use on future spacecraft such as the European Automated Transfer Vehicle, a servicing vehicle for the International Space Station. This paper presents how the computer participates in the spacecraft safety concept with emphasis on the critical on-orbit rendezvous phase. The functional architecture of the computer pool is described addressing fault containment layers, inter-channel synchronisation, communication, failed channel detection and passivation. Lastly, the hardware and software design of the test bench, built up to validate this new computer pool, is presented together with some performance measurements.