The Unitary Plan Act, passed by Congress in 1949, was a coordinated national plan of facility construction that encompassed the National Advisory Committee for Aeronautics (NACA), Air Force, industry, and universities. In 1956, under the leadership of Dr. Abe Silverstein and Eugene Wasliewski, the 10×10 was brought on line. Dr. Silverstein was responsible for the Mercury program, and for all unmanned satellite programs for the first three years of the agency. He named the Apollo program and laid the groundwork for that program’s success in landing a man on the Moon.
Throughout its history, the tunnel has made valuable contributions to the advancement of fundamental supersonic propulsion technology, the development of Atlas-Centaur, Saturn and Atlas-Agena class launch vehicles, and vehicle-focused research programs including the High-Speed Civil Transport, the National Aerospace Plane, and the Joint Strike Fighter.
The test section is 10 ft high by 10 ft wide by 40 ft long and can accommodate large-scale models, full-scale engines and aircraft components. The 10×10 was specifically designed to test supersonic propulsion components such as inlets and nozzles, propulsion system integration, and full-scale jet and rocket engines. It can operate as a closed-loop system (aerodynamic cycle) or open-loop system (propulsion cycle), reaching test section speeds of Mach 2.0 to 3.5 and very low speeds from 0 to Mach 0.36. Gust and Mach plates are sometimes installed to expand local Mach number conditions between Mach 1.5 and 4.1. There is also continuous operation across the entire speed and altitude regime, offering users greater flexibility and productivity during testing.
In the propulsion cycle, the tunnel operates by continuously drawing outside air through a very large air dryer to remove the moisture and exhausting it back into the outside environment. This mode is used for models that introduce contaminants into the air stream or use potentially explosive gas mixtures or when the tunnel air-heater is used to simulate flight temperatures. During the aerodynamic cycle, the tunnel runs as a variable density facility that can simulate pressure altitude conditions ranging from 50,000 to 154,000 feet. Dry air is added to maintain test conditions.
The facility is controlled and operated by a digital distributed control system in order to maximize data quality while minimizing operational costs. Steady state and dynamic data is collected from the model instrumentation, processed, and displayed in engineering units and graphical formats. An optical instrumentation suite of capabilities is also used depending on test requirements. To increase test productivity, a test matrix sequencer automatically changes model variables by using a pre-programmed test matrix. Real time transmission and display of all test data and information can be provided to customer locations outside of NASA Glenn.
