The Deep Impact Test Benches - Two Spacecraft, Twice the Fun

The Jet Propulsion Laboratory's Deep Impact (DI) Project was a smashing success with its successful Impact and Flyby Encounter on July 4, 2005 (UTC). Deep Impact launched the flight system, consisting of two spacecraft, on January 12, 2005 for an Encounter with comet Tempel 1 just 6 months later. The two spacecraft, known as the Flyby and the Impactor, were separated 24 hours prior to Encounter, whereby the Impactor targeted itself to a collision course with Tempel 1 and the Flyby captured the event as it flew by the comet. Ball Aerospace and Technologies Corporation (BATC) located in Boulder, CO. was the system contractor for the Deep Impact spacecraft. BATC also developed the DI Test Benches. Test benches are developed by a flight project to provide an effective platform for developing flight software and mission sequences, to offload the flight system for pre-launch validation and verification efforts, and to reliably represent the flight system for development and anomaly resolution post-launch. The success of Deep Impact was heavily reliant on these valuable project resources. Developing and operating two spacecraft simultaneously required a unique test bench architecture that could support the various configurations of the DI mission. This paper presents an overview of the Deep Impact test bench architecture. The process and challenges of operating the test benches, specifically in testing Impactor sequences, are described. Lessons learned from the test bench experience on Deep Impact are shared