The Jet Propulsion Laboratory began in the 1930s, as a rocket test site at a dry wash in the foothills near Pasadena. In a few decades it grew into a built up research and development engineering campus that was one of the principal drivers of aerospace in Southern California, and the world. JPL officially opened in 1944 as the Army Rocket Center, and most of its programs through the 1950s were classified, and related to weapons, defense, and satellite programs. JPL built the first American satellite, Explorer 1, which was launched from Cape Canaveral in 1958. After becoming a NASA site in 1959, JPL diversified into lunar and interplanetary missions and deep space probes. In addition to its main campus at the Arroyo Seco, JPL operates a number of remote antenna and test sites, including the Goldstone Deep Space Network of antennas in the Mojave. Like the Aerospace Corporation and MITRE, it is a federally funded research and development center, and is owned by NASA, and managed by Caltech. More than 6,000 people work at JPL.