Preliminary Investigation of Lunar Positioning, Navigation and Timing (PNT) Using Butterfly and Elliptical Frozen Orbits
Document Type
Article
Publication Date
6-13-2025
Abstract
As missions to cislunar space and the lunar surface grow in number and increase in complexity, the requirement for persistent position, navigation, and timing (PNT) capabilities become crucial to ensure mission safety and assurance. This paper proposes several lunar PNT architectures with constant coverage of the lunar South Pole and near constant coverage of the entire lunar surface. Investigated in this paper are orbits propagated in the Circular Restricted Three Body Problem (CR3BP) and Bi-circular Restricted Four Body Problem (BCR4BP). Orbits studied include the Butterfly family and Elliptical Lunar Frozen Orbits (ELFOs). Further analysis including position and geometric dilution of precision, stability, visibility coverage, and PNT system power considerations is performed on these architectures to narrow options to the best fit. Several Monte Carlo campaigns are performed to find constellations that meet PNT requirements with fewer satellites. These constellation designs are compared against the constellations with equidistant satellites to determine the effect of satellite phasing on PNT service. For South Pole coverage, two ELFOs with randomized satellite placement yields best results. For whole lunar surface coverage, a constellation of four ELFOs with equidistant satellite placement is best.
Source Publication
Aerotecnica Missili & Spazio (ISSN 0365-7442 | eISSN 2524-6968)
Recommended Citation
Roberts, K.R., Bettinger, R.A. Preliminary Investigation of Lunar Positioning, Navigation and Timing (PNT) Using Butterfly and Elliptical Frozen Orbits. Aerotec. Missili Spaz. 105, 269–284 (2026). https://doi.org/10.1007/s42496-025-00278-0
Comments
The full article is available from Springer via subscription or purchase, using the DOI link on this page.
The article was published as an article of the journal in June 2025 ahead of inclusion in the April 2026-dated issue cited.