Adaptive Reachability Analysis to Achieve Mission Objectives in Strongly Non-Keplerian Systems

Abstract

Adaptive numerical reachability analysis is studied as a tool for coping with sensitive, strongly non-Keplerian dynamics when planning impulsive spacecraft maneuvers in pursuit of mission objectives at small-body systems. The concept of an objective reachability map is developed beginning from analytical results for the Kepler problem and is shown to become intricately structured for the environments of asteroid Itokawa and Martian satellite Phobos. An existing method for efficient map computation via heuristic refinement, originally applied to chart safety outcomes on a planar maneuver domain, is extended for application to spherical domains and two types of non-Boolean science objectives defined for target locations on the body surface: cumulative observation time and surface payload deployment accuracy. In addition to its potential as a tool for preliminary mission design and the general study of small-body dynamics, this reachability analysis method is also examined and discussed as a resource for receding-horizon planning onboard an autonomous spacecraft.