Cislunar Mean-Motion Resonances: Definitions, Widths, and Comparisons with Resonant Satellites
Anjali Rawat, Bhanu Kumar, Aaron J. Rosengren, Shane D. Ross
TL;DR
This work develops a global, geometry-driven portrait of cislunar mean-motion resonances beyond GEO using the planar PCR3BP. By constructing Poincaré maps on a perigee section and computing stable resonant islands and their unstable manifolds, it quantifies stable resonance widths and expansive chaotic zones for the 2:1 and 3:1 MMRs, across a range of Jacobi constants. The study shows that PCR3BP widths exceed semi-analytical predictions and align with high-fidelity ephemeris propagations for spacecraft such as TESS, IBEX, and Spektr-R, reinforcing the relevance of MMRs in xGEO dynamics and mission design. It further demonstrates how perigee mappings to geocentric elements and the $(\varpi,a)$ plane can validate the resonance character of real trajectories, suggesting broad applicability for cislunar SDA and trajectory planning. Future directions include extending to 3D dynamics, heteroclinic transfers among resonances, and four-dimensional Poincaré maps to capture full spatial effects.
Abstract
Lunar mean-motion resonances (MMRs) significantly shape cislunar dynamics beyond GEO, forming stable-unstable orbit pairs with corresponding intermingled chaotic and regular regions. The resonance zone is rigorously defined using the separatrix of unstable resonant periodic orbits surrounding stable quasi-periodic regions. Our study leverages the planar, circular, restricted three-body problem (PCR3BP) to estimate the (stable) resonance widths and (unstable) chaotic resonance zones of influence of the 2:1 and 3:1 MMRs across various Jacobi constants, employing a Poincaré map at perigee and presenting findings in easily interpretable geocentric orbital elements. An analysis of the semi-major axis versus eccentricity plane reveals broader regions of resonance influence than those predicted by semi-analytical models based on the perturbed Kepler problem. A comparison with high-fidelity 3-dimensional ephemeris propagation of several spacecraft - TESS, IBEX, and Spektr-R - in these regions is made, which shows good agreement with the simplified CR3BP model.
