<p dir="ltr">Within the aerospace community in recent years, there has been a marked increase in interest in cislunar space. To this end, the study of the dynamics of this regime has flourished in both quantity and quality in recent years, spearheaded by the use of simplified dynamical models to gain insight into the dynamics and to generate viable mission concepts. The most popular and simple of these models, the Circular Restricted Three-Body Problem, has been thoroughly explored to meet these goals (even well-prior to the recent spike in interest). Much work has been done investigating periodic orbits within these models, and similarly has been performed on non-periodic transfers into periodic orbits. Studied less is the superposition of these two concepts, or using periodic orbits as a way to transit, for example, cislunar space. In this thesis, the development of periodic orbits amenable to transiting is accomplished. Beginning from periodic orbit families already present in the literature, this research finds a novel and useful family of periodic orbits, here dubbed the spatial 2:1-resonant orbit family. Within this newly-discovered family, multitudes of qualitative behaviors interesting to the astrodynamics community are found. Many family members seem accommadating to a diverse set of mission profiles, from purely-unstable family members best suited to use as transfers, to marginally stable ones best suited to longer-term use. This family as a whole is analyzed and catalogued with thorough descriptions of behavior, both quantitative and qualitative. While the Circular Restricted Three-Body Problem serves as an excellent starting point for analysis, trajectories found there must be generalized to higher-fidelity modeling. In this spirit, this thesis also focuses on demonstrating such generalization and putting it into practice using the more sophisticated Elliptic-Restricted Three-Body Problem. Documentation of the numerical tools necessary and helpful in accomplishing this generalization is included in this work. Prototypically, the truly 2:1 sidereally-resonant unstable member of the 2:1 family is transitioned into the elliptic problem, as is a nearly-stable L2 Halo orbit family member. This new trajectory is paired with a more classically-present example to show the validity of the methodology. To aid this analysis, symmetries present within the elliptic model are also explored and explained. With this analysis completed, this orbit family is demonstrated to be both interesting and useful, when considered under even more realistic modelling. Further work to mature this novel family of orbits is merited, both for use as the fundamental building block for transfers and for use for more-permanent habitation. More broadly, this work aims to achieve a further proliferation of the merger between transfer and orbit, concepts which seem distinct at first, but deserve more gradual consideration as different flavors of the same idea.</p>