Long Duration Stability of Distant Retrograde Orbits

Abstract

This paper studies the stability of distant retrograde orbits (DROs) in the Earth-Moon system over periods of 100 years or greater. This is relevant to NASA’s Asteroid Redirect Mission (ARM), which requires a stable quarantine orbit around the Moon to deposit a captured asteroid into. This research shows which perturbing forces affect the stability of a DRO, how they do so, and the DRO sizes that are resistant to instability caused by these perturbations. Results show that solar gravity is the only perturbing force that significantly impacts the stability, and that DROs with an x-amplitude between 60,000 and 68,000 km are most stable. This paper also identifies stable manifolds of a stable DRO that could be used to capture the asteroid without the need of thrusting once it approaches the Earth-Moon system.