I express my sincere appreciation to the members of my advisory committee for their guidance and support during my time in the master's program at the University of North Dakota. I also want to express my appreciation for my wife, Diana, and my daughter, Sarah, who kept the home fires burning while Dad spent many nights and weekends at the office working on "his space stuff". I want to thank Mr. Charles L. (Les) Johnson, Deputy Manager of the Advanced Concepts Office at Marshall Space Flight Center. Mr. Johnson was keenly interested in the work and assisted me in locating subject matter experts when needed. I also want to thank Mr. Patrick S. McRight, Manager of the Propulsion Systems Design & Integration Division at Marshall Space Flight Center. Mr. McRight tutored me on the complexities of cryogenic propellant storage and transfer, and frequently made himself available as a sounding board for my ideas. Mr. Steven G. Sutherlin, a Propulsion Systems Engineer in the Marshall Space Flight Center Advanced Concepts Office, also contributed enormously to my effort. We discussed spacecraft design and its influence on propellant boiloff. Mr. Sutherlin also helped me wrestle with characterizing the thermal environment at different points in space, and checked my boiloff calculations with in-house tools he uses in his work. I am deeply grateful. Mr. Larry Kos, a mission designer in the Marshall Space Flight Center Advanced Concepts Office, contributed his expertise regarding the thrust-to-weight ratio for lunar vehicles. xiii Mr. Robert Werka, a Senior Aerospace Flight Systems Engineer at Marshall Space Flight Center, contributed his expertise regarding rocket engine oxidizer-to-fuel ratios, as well as his friendship. Lastly, I want to thank Dr. Alan Wilhite, Distinguished Langley Professor of Advanced Aerospace Systems Architecture at the Georgia Institute of Technology. While we only corresponded by email, Dr. Wilhite introduced me to the Modified Lockheed Model, and responded to my many questions as if I were one of his own students. Dr. Wilhite retired in December, 2014. xiv ABSTRACT Heretofore, discussions of space fuel depots assumed the depots would be supplied from Earth. However, the confirmation of deposits of water ice at the lunar poles in 2009 suggests the possibility of supplying a space depot with liquid hydrogen/liquid oxygen produced from lunar ice. This architecture study sought to determine the optimum architecture for a fuel depot supplied from lunar resources. Three factorsthe location of propellant processing (on the Moon or on the depot), the location of the depot (on the Moon or in cislunar space), and if in cislunar space, where (LEO, GEO, or Earth-Moon L1), and the method of propellant transfer (bulk fuel or canister exchange) were combined to identify 18 potential architectures. Two design reference missions (DRMs)a commercial satellite servicing mission and a Government cargo mission to Marswere used to create demand for propellants, while a third DRMa propellant delivery missionwas used to exa...