This is the first full-length history of the X-43 project, written by the project historian at Dryden Flight Research Center. The project achieved the first in-flight testing of a scramjet engine, at speeds of nearly Mach 7 and Mach 10.The author recorded the history as it was taking place. He received updates and documents, attended the engineering meetings, witnessed the emergency procedure training of the flight controllers, was at the flight readiness review and preflight briefings, and watched the third flight from one of the control rooms. After the third flight, he interviewed many of the X-43A engineers and managers about their still-fresh experiences and recollections.Based on that exclusive access, the book illustrates - with real-world examples - how groundbreaking technology unfolds. It details the development of the scramjet over the last half-century, providing the reader with an understanding of how external factors influence a new technology.The book begins with the invention of the scramjet concept, and then details the projects of the 1960s through the 1980s and why they failed.It describes how the X-43 developed from these events, and follows the transformation from the original idea through hardware development and testing, the loss of the first vehicle, the return to flight, and the success of the second and third flights, and explains what was accomplished.The book is written with the engineering student in mind, to provide an understanding of what they will experience once they join the work force. Flight enthusiasts will love the photos and videos documenting this exciting program. This volume was produced in cooperation with the National Aeronautics and Space Administration.