File:High-Energy Propellant Rocket Firing at the Rocket Lab (GRC-1955-C-37428).jpg

English: A rocket using high-energy propellant is fired from the Rocket Laboratory at the National Advisory Committee for Aeronautics (NACA) Lewis Flight Propulsion Laboratory. The Rocket Lab was a collection of ten one-story cinderblock test cells located behind earthen barriers at the western edge of the campus. The rocket engines tested there were comparatively small, but the Lewis researchers were able to study different configurations, combustion performance, and injectors and nozzle design. The rockets were generally mounted horizontally and fired, as seen in this photograph of Test Cell No. 22. A group of fuels researchers at Lewis refocused their efforts after World War II in order to explore high energy propellants, combustion, and cooling. Research in these three areas began in 1945 and continued through the 1960s. The group of rocket researches was not elevated to a division branch until 1952. The early NACA Lewis work led to the development of liquid hydrogen as a viable propellant in the late 1950s. Following the 1949 reorganization of the research divisions, the rocket group began working with high-energy propellants such as diborane, pentaborane, and hydrogen. The lightweight fuels offered high levels of energy but were difficult to handle and required large tanks. In late 1954, Lewis researchers studied the combustion characteristics of gaseous hydrogen in a turbojet combustor. Despite poor mixing of the fuel and air, it was found that the hydrogen yielded more than a 90-percent efficiency. Liquid hydrogen became the focus of Lewis researchers for the next 15 years.