Here, we develop a simple mathematical model of an adsorbed xenon propellant storage system that enables us to evaluate and rank adsorbents for adsorbed xenon propellant storage. Our objective is to minimize the mass of storage materials required to carry the xenon propellant needed for the mission. For conventional, bulk xenon storage, the storage material is comprised of the material composing the walls of the pressure vessel. For adsorbed xenon storage, the storage materials are comprised of the walls of the pressure vessel and the mass of the adsorbent material. Using our model, we find the optimal storage pressure that minimizes the mass of the storage materials, under both bulk and adsorbed xenon storage strategies. The optimized conventional, bulk storage system serves as a baseline for evaluating porous materials for adsorbed xenon storage.