Separating the Real from the Imagined relates the history of flight research practiced from 1915 to 1998 by the National Advisory Committee for Aeronautics (NACA) and its successor the National Aeronautics and Space Administration (NASA). While it covers many subjects, it is not a comprehensive, exhaustive, or encyclopedic treatment. Rather, it represents a selective overview in which projects illustrative of an era, of pivotal technologies, or of advances in the art of flight research itself receive most of the coverage. Its overall intents is to emphasize some of the major themes, events, and accomplishments in this sometimes misunderstood field of aeronautics, to provide historical perspective about the development of the discipline, and to demonstrate the ways in which it contributed not just to the design and improvement of aircraft, but to that of spacecraft as well.