This book reviews the remarkable efforts to develop a new aircraft configuration known as the Blended Wing-Body (BWB). Responding to a challenge from NASA, McDonnell Douglas Corporation initiated studies in the early 1990s to determine if this new configuration could bring about significant advantages over conventional sweptwing, streamlined tube, and swept-tail designs. Challenges were identified and this information allowed the design and construction of two small-scale demonstrators: the X-48B. After McDonnell Douglas' merger with Boeing, the X-48B flew 92 test flights before modification into the X-48C, which in turn flew 30 flights under the auspices of NASA's Environmentally Responsible Aviation Program.