Date of Award
3-2024
Document Type
Thesis
Degree Name
Master of Science in Aeronautical Engineering
Department
Department of Aeronautics and Astronautics
First Advisor
Robert A. Bettinger, PhD
Abstract
In the renewed 21st-century race to the Moon, the demand for heightened mission capabilities in the cislunar region, lunar surface, and beyond is imperative. With an escalating number and complexity of lunar missions, persistent positioning, navigation, and timing (PNT) capabilities are becoming paramount. This thesis presents innovative lunar PNT architectures designed to provide continuous coverage of the lunar South Pole, near-continuous coverage of the entire lunar surface, and coverage of the Earth-Moon Corridor. As space faring countries advance from lunar exploration to Mars, similar assets are essential for astronaut exploration in this extraterrestrial environment. Additionally, this thesis introduces and meticulously analyzes several constellations for Mars and Phobos PNT. The research delves into orbits propagated in the Circular Restricted Three Body Problem (CR3BP) and Bi-Circular Restricted Four Body Problem (BCR4BP) through methods such as initial condition propagation and Poincaré Mapping. A comprehensive performance analysis is conducted, considering factors such as visibility coverage, system power considerations, position dilution of precision, geometric dilution of precision, and stability in both three-body and four-body systems. These analyses are crucial for narrowing down the options and identifying the most fitting architectures. For South Pole coverage, the study favors a constellation of Elliptical Lunar Frozen Orbits (ELFOs) due to its consistent coverage of the lunar South Pole. In the case of entire lunar surface coverage, two constellations of ELFOs and Walker Deltas emerge as equally viable options. Earth-Moon coverage, deemed challenging due to the vastness of space, leans towards a 3:1 Resonant Orbit with a Distant Retrograde Orbit (DRO) and a 2.5 xGEO orbit as a potentially optimal constellation. Moving beyond the Moon, an Axial constellation surpasses expectations for Martian PNT. For Phobos PNT, the architecture design falls back on a Walker Delta constellation. The thesis concludes with numerous findings and recommendations, including a comprehensive exploration in the appendix that sheds light on the profound impact of optimizing satellite placement on results.
AFIT Designator
AFIT-ENY-MS-24-M-202
Recommended Citation
Roberts, Kaitlin R., "Positioning, Navigation, and Timing (PNT) Study for Select Multibody Environments" (2024). Theses and Dissertations. 7894.
https://scholar.afit.edu/etd/7894
SF298 for AFIT-ENY-MS-24-M-202 - Roberts, K
Comments
A 12-month embargo was observed for posting this work on AFIT Scholar.
Distribution Statement A, Approved for Public Release. PA case number on file.
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