|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.
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.