High Fidelity Dynamics Modeling for Near Earth and Cislunar Space Incorporating Non Conservative Effects

open_access
Open Access
Author:
Robinson, Audra
Area of Honors:
Aerospace Engineering
Degree:
Bachelor of Science
Document Type:
Thesis
Thesis Supervisors:
Roshan Thomas Eapen, Thesis Supervisor
Sven Schmitz, Thesis Honors Advisor
Keywords:
Cislunar Space
High-Fidelity Modeling
xGEO
SGP4
Abstract:
Space Situational Awareness aims to provide comprehensive and accurate knowledge of all near-Earth-orbiting objects, now extending to the cislunar realm. This requires maintaining a catalog of space objects' states (position and velocity), with numerical simulations filling observational gaps. A high-fidelity orbit propagation model is developed using a cannonball spacecraft assumption and incorporating perturbative effects from spherical harmonics, Luni-Solar third-body influences, atmospheric drag, and solar radiation pressure. The model is compared with standard solvers such as Simplified General Perturbations 4 (SGP4) for spacecraft in Low Earth Orbit (LEO), Medium Earth Orbit (MEO), Geostationary Orbit (GEO), and the cislunar domain. Error analysis reveals that SGP4 exhibits exponentially increasing inaccuracies over time, making it suitable for short-duration predictions. Additionally, long-term trends in orbital element evolution due to perturbations are examined. Finally, cislunar orbit designs at various resonant frequencies are analyzed and compared with SGP4. These findings offer insights into orbital evolution, the limitations of SGP4 over extended time frames, and the role of high-fidelity modeling in optimizing orbit design in near-Earth and cislunar space.