STAR TOPOLOGY SPACECRAFT DATA BUS

Abstract

Significant advances in processing power and hardware miniaturization for aerospace applications has led to new distributed avionics architectures. These architectures have driven system data transmission requirements to the point where current data communications and interconnect technologies are marginal or inadequate. Advanced spacecraft including Space Station and SDI platforms have identified the need for distributed processing and real time control, requiring large and complex data communications networks with bus data rates in the 100 to 500 MBPS range. To address this need a new communications protocol has been developed to provide high data rate and very short transport delay performance. The protocol is implemented using a star topology fiber optic data bus. During the design of this system for spacecraft data bus applications, particular attention was paid to system robustness, redundancy, fault tolerance, autonomy, and error control. The salient system design, hardware configuration, and performance of an eight node demonstration network jointly developed by NASA Goddard and Sperry Corporation are presented in this paper.