Dish radio antenna

Built by SRI for the U.S. government in the early 1960s, the 150-foot movable radio reflector antenna near Stanford University (known locally as “the Dish”) was the world’s third largest upon its completion. It has been operated by SRI since then and is used today for satellite calibrations and spacecraft communications.

On October 10, 1957, a smaller SRI antenna near the Dish made the first radar detection of an artificial satellite—in fact, the satellite was the world’s first, Sputnik 1, which had been launched six days earlier by the Soviet Union.