Follow this link to skip to the main content
Jet Propulsion Laboratory, JPL, NASA, National Aeronautics and Space Administration, Caltech, California Institute of Technology View the NASA Portal
homeearthsolar systemstars galaxiestechnology
JPL History banner
1936 - 1958
Home History
Early History
First Space Missions
New Directions
Grand Voyages
the 80s
the 90s
  printer-icon  Print this page


July 1957 marked the beginning of the International Geophysical Year, when scientists around the world planned to jointly observe various scientific phenomena. It was during this period of scientific cooperation that the Soviet Union stunned the world with the launch of Sputnik, the first satellite ever. On October 4, 1957, the USSR put into orbit a tiny sphere with a radio transmitter that beeped its way into history. The JPL community was surprised that the Soviets could have both a successful launch vehicle and the electronic technology to operate the satellite.

The United States needed an immediate response. The first attempt, the Naval Research Lab's Vanguard project, failed. Their rocket exploded in full view of the press, embarrassing the nation.

Explorer 1 video-JPL's role in Explorer 1 marked the lab's shift in emphasis from rockets to satellites and spacecraft

JPL and the U.S. Army's Ballistic Missile Agency in Huntsville, Alabama, then pooled resources and knowledge. In about 80 days a four-stage rocket was assembled. JPL's canister-shaped Explorer 1 satellite formed the nose of the rocket.

On January 31, 1958, Explorer 1 launched and became the first U.S. satellite, using its single instrument to send back data about the radiation environment high above Earth's surface.

This started the "space race" with the Soviet Union.

Explorer 1
  A model of Explorer 1, held by JPL's Director William Pickering, scientist James Van Allen and rocket pioneer Wernher von Braun.
+ Full image


  Explorer Satellites - Explorer1 made the first detection of radiation trapped by Earth's magnetic field, later named the Van Allen radiation belts for the intrument's inventor. More than fifty Explorers were launched over the next 15 years to study radiation, particles and magnetic fields. After 1960, however, JPL turned the Explorer series over to the new Goddard Space Flight Center in Greenbelt, Md., and focused its attention on planetary exploration with its Mariner, Ranger and Surveyor spacecraft projects.
    Next >
Privacy / Copyrights    FAQ   Contact JPL
Link to + Freedom of Information Act View NASA Home Page    
JPL Historian: Erik Conway
Site Manager: Susan Watanabe
Webmasters: Tony Greicius, Martin Perez