Date of Award
Doctor of Philosophy (PhD)
Aerospace Engineering Sciences
Jeffrey S. Parker
Distant retrograde orbits (DROs) are a neutrally stable class of three-body orbits. Because of their stability, DROs cannot be targeted with a low-energy transfer along a stable manifold like unstable three-body orbits in the circular restricted three-body problem (CR3BP). However, in more complicated dynamical models, the effects of small perturbing forces can be exploited to build ballistic capture trajectories (BCTs) into DROs. We develop a method for building sets of BCTs for a particular reference DRO with recommendations for minimizing computational effort. Sets of BCTs are generated in the Earth-Moon system and the Mars-Phobos system due to their applicability to near-term missions and large difference in mass parameters. These BCT sets are stochastically analyzed to determine the range of conditions necessary for using a BCT, such as energy, solar system geometry, and origin. The nature of the DRO after the spacecraft is captured is studied, including minor body flyby altitudes and variations in the size and shape over time.
After a spacecraft has used a BCT, it can decrease its sensitivity to perturbations and extend its mission duration with a series of stabilizing maneuvers. Quasi-periodic orbits are constructed in the Earth-Moon CR3BP that lie on the boundary of stability, and closely resemble the DROs that result from using a BCT. Minimum cost transfers are then constructed between these quasi-periodic orbits and a target periodic DRO using a variety of methods for searching and optimizing. It is discovered that BCTs that target planar quasi-periodic DROs can be stabilized for about 15\% of the cost of stabilizing a BCT with large out-of-plane motion.
Once a spacecraft is in a stable DRO, the long duration evolution of that orbit is of interest. Using a high fidelity dynamical model and numerical precision techniques, the evolution of several DROs in the Earth-Moon system is studied over a period of 30,000 years. The perturbing forces that cause a DRO to transition into an unstable orbit are identified and analyzed. DROs larger than 60,000~km grow in amplitude due to solar gravity until they depart the Moon after several centuries. DROs smaller than 45,000~km remain stable for 25,000 years or more, but decay in size due to the Moon's solid tide bulge, which eventually causes the DRO to depart the Moon. The DROs evolve chaotically and occasionally experience periods of relatively fast amplitude growth when the period of the DRO is in resonance with the frequency of particular perturbing forces.
Bezrouk, Collin J., "Ballistic Capture into Lunar and Martian Distant Retrograde Orbits" (2016). Aerospace Engineering Sciences Graduate Theses & Dissertations. 147.