Discovering Earth's Radiation Belts: Remembering Explorer 1 and 3



On 31 January 1958, at 10:48 P.M. eastern standard time, the United States launched its first satellite, Explorer 1, on a modified Jupiter-C rocket.

Later, at about 1:30 A.M., after confirming that it was indeed in orbit, three men triumphantly held aloft a full-scale model of Explorer 1 at a crowded press conference in the Great Hall of the National Academy of Sciences (Figure 1). In the center stood James A. Van Allen, head of the physics department at the University of Iowa and the scientist responsible for the scientific experiment. Flanking him were Wernher von Braun, director of development operations for the Army Ballistic Missile Agency (ABMA), which was responsible for constructing the Jupiter-C, and William H. Pickering, director of the Jet Propulsion Laboratory (JPL), which provided the Explorer spacecraft, the solid-fueled upper stages, and the guidance and control system. The United States had just successfully entered the race to explore, understand, and utilize space.