Pablo Machuca, University of California San Diego; Aaron J. Rosengren, University of California San Diego; Shane D. Ross, Virginia Tech
Keywords: Orbit Determination, Uncertainty Quantification, Astrodynamics
Abstract:
Maintaining a catalog of resident space objects beyond GEO (xGEO) represents a new challenge for Space Domain Awareness (SDA). With the Lunar Gateway and increased international efforts to explore and exploit the Moon and cislunar space, a plethora of dynamically complex xGEO orbits are expected to be populated in the coming years. A better understanding of the intrinsic stability properties of such orbits, station-keeping requirements, and deep-space surveillance is needed for improved SDA in this non-traditional orbital environment. This study aims to address topics of fundamental significance for xGEO SDA, including: (1) characterization of the dynamical environment and common trajectories of interest; (2) effective and intuitive parameterizations that describe the orbital motion of xGEO objects in multi-body environments; and (3) quantification of inaccuracies and uncertainties in the orbit determination (OD) process. Such efforts will help improve understanding of viewing geometries and required observation campaigns for xGEO catalog maintenance.
Specifically, we reproduce and characterize, in a high-fidelity ephemeris model, common mission scenarios of interest: e.g., (a) transfers between quasi-periodic halo orbits (including that baselined for the Lunar Gateway); and (b) transfers into distant retrograde orbits (DROs), which have been proposed as parking orbits for interplanetary missions. We then propose a parameterization approach to describe such trajectories based on piecewise orbital elements (geocentric or selenocentric, as the physical picture dictates). We show that, despite the non-Keplerian nature of these restricted three-body orbits, the classical elements are still well defined and provide an intuitive and familiar representation of characteristic xGEO trajectories. Additionally, we quantify, model, and propagate inaccuracies and uncertainties involved in the OD process to better understand the inherent sensitives that plague xGEO. Finally, we study the effects of these uncertainties on viewing geometries, required revisit rates, and surveillance volumes.
Date of Conference: September 27-20, 2022
Track: Cislunar SSA