This scholarly look at the Altitude Wind Tunnel covers the transformations the wind tunnel made in its long history from a wind tunnel doing full-scale testing for wartime applications, to a vacuum chamber supporting the Vision for Space Exploration, and even a brief period as home to Mercury astronaut training. The book also addresses the attempts to resurrect the facility and its eventual decommissioning and demolition. The Altitude Wind Tunnel's (AWT) steel shell loomed, almost threateningly, over the National Aeronautics and Space Administration (NASA) Glenn Research Center s main campus in Cleveland, Ohio, for over 60 years. The facility had been inactive since 1975, but the hulking tunnel sat in a conspicuous location between the visitors' center and the Icing Research Tunnel and was seen daily by hundreds, if not thousands, of people. The tunnel slowly ebbed from NASA Glenn's collective consciousness. Inside the steel shell, significant contributions had been made in the advancement of the jet engine and the high-profile Project Mercury and Centaur Program. Yet, the AWT had remained a mystery to most current employees and the public. Not only did the rusting giant have an obscure past, few even knew its name. This book and other documentation have been created to resurrect the esteemed reputation of this once-vital and historically significant facility. The AWT's unrivaled capability to test full-scale engines in simulated altitude conditions advanced the development of the jet engine considerably during its formative period in the 1940s and in its maturity in the 1950s. The AWT was the nation's first wind tunnel built specifically to study the operation of engines. Its ability to consistently re-create flight conditions allowed researchers to systematically study engine behavior and perfect innovations such as the afterburner and the variable-area nozzle. Between 1959 and 1963 the AWT was slowly transformed into two large test chambers. The tunnel's simulated high-altitude conditions allowed NASA to cancel costly and time-consuming flight testing for Project Mercury. Afterward the tunnel was converted into one of the nation's first large vacuum chambers and renamed the Space Power Chambers (SPC). It was used to quickly remedy a number of problems for the Centaur second-stage rocket. The SPC tests allowed the Centaur to sustain its tight schedule for the Surveyor and later orbiting observatory missions. Use of the facility tapered off in the 1970s, and an effort to resurrect the wind tunnel failed in the early 1980s. After years of neglect, the tunnel was demolished in late 2008 and spring 2009. NASA's historical publications tend to focus on center histories, specific programs (particularly the human space program), or chronologies and other reference materials. The NASA Glenn Research Center has carved out a niche by writing the histories of several of its research facilities. The Icing Research Tunnel, Rocket Engine Test Facility, and Plum Brook Reactor have all been documented in recent years. These three books appear to be the only single-facility studies in NASA's historical collection.