SpaceAGE bus: Proposed electro-mechanical bus for avionics intra-box interconnections

This paper addresses the hardware portion of an integrated hardware/software strategy to reduce cost for space avionics systems. This presented approach's cost savings is based upon the reduction of Non Recurring Engineering (NRE) through reuse of modular hardware components for follow-on missions. The hardware description focuses upon a method for building-up avionics boxes from modular board level elements, i.e., intra-box interfaces only. This approach is an improvement over other card frame approaches because it does not rely on feed through connectors; it permits ability to pull-out and/or replace random modules from the avionics box without disturbing the other modules in the stack; it provides a systematic method to add cards providing a wide range of “backplane” signal definitions applicable to 90% of space missions with protocols that can be defined on a per module basis within an avionics box; and provides an up to 3.125 Gbps full duplex communications via a non-blocking cross-bar switch to allow multiple modules to communicate simultaneously. It is currently being used to implement the flight hardware computer system for the Laser Communication Relay Demonstration (LCRD) project: awarded to Goddard Space Flight Center (GSFC) by NASA Office of Chief Technology.