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.