Ares I Avionics Introduction

The Ares I is the next generation human-rated launcher for the United States Constellation program. This system is required to provide single fault tolerance within defined crew safety and mission reliability limits. As part of the effort to achieve those safety goals, Ares I includes an avionics subsystem built as a multistring, voting architecture. The avionics design draws upon experience gained from building fly-by-wire systems for Shuttle, X- 38, and Seawolf. Architectural drivers for the avionics design include using proven technologies with existing suppliers of space rated parts for critical functions (to reduce overall development risk), easing the software development effort by using an off-theshelf, DO-178B certifiable, ARINC-653 operating system in the main flight computers, minimizing mutual data and power connections that might lead to a common-mode hardware failure of the redundant avionics strings, and centralizing overall Ares I command & control within the Upper Stage.