Autonomous Optical-Only Spacecraft-to-Spacecraft Absolute Tracking and Maneuver Classification in Cislunar Space

Abstract

Traditional concerns regarding spacecraft state estimation are exacerbated in cislunar space due to highly nonlinear dynamics, limited observational information, and increasingly overloaded Earth-based resources. These challenges motivate research into space-based navigation and observation capabilities that provide opportunities for autonomy. This paper demonstrates that relative optical measurements provide full inertial estimates of an agent and target spacecraft, while simultaneously enabling classification of unknown maneuvers in the cislunar environment. To achieve this objective two subtasks are demonstrated. First, the spacecraft-to-spacecraft absolute tracking method, which estimates the absolute state of two vehicles using relative measurements, is tested for observability and shown to produce consistent filter solutions given optical sensors. Second, maneuver classification is performed by labeling an estimated control profile generated from the optimal control based estimator. Collectively, this sequential methodology enables an agent craft to autonomously navigate itself while observing a target craft and classifying its maneuvers.