Quasi-frozen polar orbits and resonance effects in low-altitude orbits around the Moon

In this work, we analyze orbits around the Moon, considering the primary perturbing forces, including the effects of the selenopotential, third-body perturbation and solar radiation pressure (SRP). We adopt a simplified model with zonal truncation up to order eighteen, incorporating sectoral and tesseral terms of order and degree three, named Model 18 × 3. Additionally, we develop an analytical model that includes zonal harmonics up to the J 18 term, named Model 18 × 0. With the analytical model, we analyze the conditions of frozen orbits when the perilune argument is 270 and 90 degrees. We show the results in graphs of eccentricity versus inclination, where we obtain initial conditions of frozen orbits. Numerically integrating the equations of motion using the initial conditions obtained in the analytical model, we identify quasi-frozen polar orbits and regions of large eccentricity variation that can aid in the removal of space debris. To validate the results, we used the GMAT software considering the selenopotential model of order and degree 50 × 50.