LOW-THRUST TRAJECTORIES BETWEEN HALO-ORBIT TORI INTERSECTIONS IN THE CIRCULAR RESTRICTED THREE BODY PROBLEM

With renewed interest in returning back to Earth’s Moon, it is becoming increasingly important to develop corridors of travel that can further reduce flight cost and increase the number of transfer options into Cislunar space. The dynamics in Cislunar space are more complex, where Two-Body Problem approximations break down. Dynamical Models like the Circular Restricted Three-Body Problem (CR3BP) are used as a foundation to map these more complex dynamics. Periodic Orbit transfers are one set of solutions that are used, allowing a spacecraft to transfer from one Orbit to another. This thesis demonstrates the use of Quasi-Periodic Orbits (QPOs) to move from one region to another that can be more cost effective. Where a Periodic Solution generates a 1-D Line, QPOs are described as a 2-D Surfaces, expanded from an underlying Periodic Orbit. Because QPOs take up spatial volume, they make for solid candidates for low-cost transfers. If two QPOs are close enough, there surfaces intersect, promoting a direct transfer opportunity between the structures. Combined with the Indirect Optimal Control method for a low-thrust controller, this thesis demonstrate that QPO intersection transfers can be viable option when moving around Cislunar space. Several QPO case studies with different classes of maneuvers were analyzed, and compared against their underlying Periodic Orbits. For nearby QPOs, the transfer-cost advantage relative to the underlying periodic-orbit transfer was often minimal and, in some cases, resulted in increased flight cost. However, for larger QPOs, there were a nontrivial savings in transfer cost as compared to the underlying Periodic Orbits. The results further indicate a broader set of low cost QPO transfers that arise from the extra spatial volume, providing many more transfer options across the QPO surface.