"Frontiers of Propulsion Science" is the first-ever compilation of emerging science relevant to such notions as space drives, warp drives, gravity control, and faster-than-light travel - the kind of breakthroughs that would revolutionize spaceflight and enable human voyages to other star systems. Although these concepts might sound like science fiction, they are appearing in growing numbers in reputable scientific journals. This is a nascent field where a variety of concepts and issues are being explored in the scientific literature, beginning in about the early 1990s. The collective status is still in step 1 and 2 of the scientific method, with initial observations being made and initial hypotheses being formulated, but a small number of approaches are already at step 4, with experiments underway. This emerging science, combined with the realization that rockets are fundamentally inadequate for interstellar exploration, led NASA to support the Breakthrough Propulsion Physics Project from 1996 through 2002. "Frontiers of Propulsion Science" covers that project as well as other related work, so as to provide managers, scientists, engineers, and graduate students with enough starting material that they can comprehend the status of this research and decide if and how to pursue it in more depth themselves. Five major sections are included in the book: Understanding the Problem lays the groundwork for the technical details to follow; Propulsion Without Rockets discusses space drives and gravity control, both in general terms and with specific examples; Faster-Than-Light Travel starts with a review of the known relativistic limits, followed by the faster-than-light implications from both general relativity and quantum physics; Energy Considerations deals with spacecraft power systems and summarizes the limits of technology based on accrued science; and, From This Point Forward offers suggestions for how to manage and conduct research on such visionary topics.