This book provides a broad treatment of relativistic rocket systems. Accordingly, many methods of relativistic rocket flight are presented with theoretical evidence of plausibility. Naturally, the proposed methods are merely theoretical. However, the physics and mathematics for enabling the conjectured systems is already largely established. The content of this books is provided in various levels of mathematics ranging from rather simple arithmetic to advanced formulas of both closed form and numerical approximations. A major focus of the content includes applications of nuclear energy for relativistic rocket flight. As such nuclear fission and nuclear fusion powered propulsion systems are explained in rather detailed manners. Unlike many of the similar works of other authors, Essig provides detailed analysis of nuclear powered spacecraft that may achieve very large Lorentz factors. Additionally, much conjecture is provided for matter-antimatter powered rockets as well as rockets that carry safely stored antimatter but extract the normal matter reactants from the background in natural and/or artificially disposed forms. In some scenarios, drag energy is assumed largely captured and recycled to enable effective specific impulse values of matter-antimatter engine exhaust approaching twice the speed of light. What is more interesting is descriptions of plausible systems for which arbitrarily greater yet specific impulse values may be obtained. In addition to propulsion, much content is provided on methods of shielding highly relativistic spacecraft from gas, dust, and other debris as well as methods of sinking drag heat as exhaust embodied thermal energy. Exotic materials are proposed in a somewhat ad hoc manner but then so with mathematical and physical arguments suggesting the various degrees of these materials refractory, reflective , and mechanical strength properties as well as volumetric densities of these material. We have come of age in the solar system. We have sent probes throughout our planetary system and currently operate outbound probes well beyond the orbit of Pluto. These probes have had their genesis from within the ancient Chinese Empire in its bold experiments with black powder rockets during the first millennium AD and in the work of visionary giants such as Robert Goddard and Werner von Braun. A complete list of important contributors is to too large to include in this book. We are forever indebted to these intellectual pioneers. Last century, we mastered the mighty power of the atom to a high degree of proficiency. We have learned to harness a cosmic energy source in the development of the atom bomb. Although tensions between the United States and Russia have seen somewhat of the resurgence, the vestiges of the tensions between the East and the West have waned in the post-Cold War years. Thus, we can now freely put the atomic genie to use for our peaceful bidding for a grand exodus out into the eternal star spangled blackness of interstellar space. Where we will go from there is any science fiction buff's guess. However, nuclear energy directly or indirectly will likely be a key that unlocks the cosmic door. The realization of our first manned starships will involve an heroic global effort made all the more heroic to a degree commensurate with a bold courage to contemplate future possibilities in cosmic dreams of glory. The required engineering programs will be Herculean in scope, the spacecraft assembly meticulously clean and detailed, the national, or more likely, global funding efforts bolder than anything humanity has ever contemplated to date. Many disciplines will be brought together under the common goal of designing, assembling, and launching our first manned starships. Folks of all occupations and economic status will be required. When the final designs are finished, the assembly is accomplished, and the crew and passengers are selected, we will enter a bold new era of star flight. Such a global effort can usher in an era of peace and prosperity. This book is part of the story of how all of this can happen by bold projections for prospects of relativistic rocket flight well into this this millennium and beyond. This is my calling. This is your calling. This is our calling. This is the Call Of The Cosmic Wild!