Automating the Pluto Experience: An Examination of the New Horizons Autonomous Operations Subsystem

New Horizons is a NASA sponsored mission to explore Pluto and its largest moon Charon. The New Horizons spacecraft, designed, built and operated by the Johns Hopkins University Applied Physics Laboratory (APL), was successfully launched in January 2006. New Horizon´s closest encounter with Pluto will occur in the summer of 2015. Upon completion of its primary science objectives at the Pluto encounter, the spacecraft is expected to visit one or more Kuiper Belt objects in the outermost region of the solar system. This long duration mission requires high reliability and imposes some demanding fault management requirements upon the spacecraft. The spacecraft is highly redundant with onboard software that provides a rule based expert system for performing autonomous fault detection and recovery. Generally referred to as Autonomy, this software´s design was largely driven by two factors, the concept of operations for the mission and the level of redundancy in the spacecraft hardware. This paper examines the unique mission requirements that drove the Autonomy design. It discusses how the Autonomy system supports all of the various phases of the mission and provides examples of how unique mission requirements of the New Horizons mission were implemented.