Autonomous Navigation System Performance in the Earth-Moon System

Abstract

As NASA continues to develop new vehicles for crewed missions beyond low Earth orbit, there is a growing need for the development of autonomous spacecraft navigation systems. Such a system would be required for the crew to safely return home in the event of a communication system failure. Earlier work has shown that optical navigation techniques offer a promising solution to this problem. The present work aims to quantify the navigation system performance of an autonomous vehicle in the Earth-Moon system as a function of major sensor/system design variables. To assess performance in the event of a communication system failure, radiometric tracking and ground-based state updates are assumed to be unavailable. Instead, the system must autonomously update its state using only images of the Earth, Moon, and stars. This study will investigate the steadystate navigation filter performance as a function of navigation system design variables (e.g. sensor resolution, measurement frequency) for a spacecraft on a number of representative trajectories for a spacecraft in lunar orbit. These results will give the designers of missions within the Earth-Moon system an easy reference for approximate autonomous navigation system performance as a function of major design variables.