English: W. Deter Straub, a scientist at the NASA Electronics Research Center's (ERC) Component Technology Laboratory, conducted this experiment with the "Gunn Effect." The Gunn Effect is the production of microwave oscillations when a constant voltage inexcess of a critical level is applied to opposite faces of a semiconductor. The Center realized the promising advances in microwave research, indicated by "hot electron" experiments atthe ERC with the use of bulk gallium arsenide semiconductormaterial. The Center's scientists generated higher frequency microwaves which were important for future NASA missions in spacecraft transmitters, because they were expected to improvethe efficiency of microwave signal transmission in space. ERC opened in September 1964 and has the particular distinction ofbeing the only NASA Center to close, shutting down in June 1970. Its mission was to develop new electronics and training new graduates as well as NASA employees. The ERC actually grew whileNASA eliminated major programs and cut staff in other areas. Between 1967 and 1970, NASA cut permanent civil service workersat all Centers with one exception, the ERC, whose personnel grewannually until its closure. For more information about the ERC, please see <a href="http://history.nasa.gov/erc.html"> http://history.nasa.gov/erc.html</a>