Explorer 3 (international designation 1958 Gamma) was an artificial satellite of the Earth, nearly identical to the first United States artificial satellite Explorer 1 in its design and mission. It was the second successful launch in the Explorer program. The satellite was launched from Cape Canaveral Air Force Station (now Kennedy Space Centre) in Florida at 17:31:00 UTC on March 26, 1958, by the Jupiter-C vehicle. Read more