The increasing scientific, commercial, and strategic importance of cislunar space has created a need for high-fidelity models, simulation tools, and analysis frameworks for orbit evaluation to support science, commercial activity, and national objectives. This dissertation addresses that need by developing modeling approaches and computational tools and by performing mission design analysis with them. The first part of this dissertation surveys a set of periodic orbits in the Circular Restricted Three Body Problem (CRTBP) in cislunar space to identify orbital candidates for a technology demonstration of starshades, a novel piece of architecture proposed for directly imaging exoplanets. The second part examines how the shape of periodic orbits change when transitioned from the idealized CRTBP model to a higher-fidelity ephemeris model. By quantifying these differences using geometric comparisons and further highlighting how these changes impact visibility of cislunar space and the lunar surface, the dissertation provides guidance on how mission designers can design with factors of safety in mind during the initial stages and how to expect the trajectory to evolve as higher fidelity modeling is incorporated. This analysis also highlights the practical limitations of periodic orbit generation in the idealized CRTBP model when applied to realistic perturbations. The final part demonstrates a method for constructing a novel family of forced, low, continuous thrust periodic orbits in an ephemeris model. Moreover, the impact of the Hall thruster propulsion system parameters has on the trajectory for a given control history is also examined. This contribution expands the set of viable cislunar orbit options available for future science, commercial logistics, and national security missions. Together, these results provide a framework for connecting theoretical N-body orbital mechanics with the practical needs of spacecraft architecture evaluation and mission design in a realistic cislunar environment.