Explorer I

Explorer-I, officially Satellite 1958 Alpha (and sometimes referred to as Explorer 1), was the first Earth satellite of the United States, having been launched at 10:48pm EST on January 31 (03:48 on 1 February in GMT), 1958, as part of the United States program for the International Geophysical Year. The satellite was launched from LC-26 at Cape Canaveral Air Force Station in Florida onboard a Juno I rocket.