Explorer I: From Rocket Science to Space Exploration
In the midst of the Cold War, the International Council of Scientific Unions declared an International Geophysical Year (IGY) for world-wide cooperation in geophysics in 1957-1958. The United States and the Soviet Union each announced plans to contribute an artificial satellite to the project. Urged on by the launch of the Soviet Union's Sputnik I and II in late 1957, the Jet Propulsion Laboratory, which had experimented with rockets and missiles up to this point, and the U.S. Army worked together to launch the Explorer I satellite into Earth's orbit on January 31, 1958. The successful launch of Explorer I was the turning point from aeronautics dominated by military rocketry to an era of civilian space exploration. This new civilian focus was eventuated in NASA, which has taken the forefront in the frontier of outer space.