INVESTIGATING THE EVOLUTION OF PRACTICAL DISTANT RETROGRADE ORBITS UP TO 30,000 YEARS

This work studies the evolution of several Distant Retrograde Orbits (DROs) in the Earth-Moon system with varying sizes and inclinations over tens of thousands of years. This analysis is relevant for missions requiring a completely handsoff, long duration quarantine orbit, such as a Mars Sample Return mission or the Asteroid Redirect Mission. Four DROs, selected from four stable size regions, are propagated with quadruple precision arithmetic and a high fidelity dynamics model for 30,000 years. The evolution of the orbit size, shape, orientation, period, out-of-plane amplitude, and Jacobi constant are tracked. It was found that small DROs, with an x-amplitude of approximately 45,000 km or less decay in size and period largely due to the Moon's solid tides. Larger DROs (62,000 km and up) are more influenced by the gravity of bodies external to the Earth-Moon system, and remain bound to the Moon for significantly less time.