Sputnik 1 starts the Space Age

The Soviet Union launched Sputnik 1, a small polished sphere that circled Earth and sent radio beeps. The surprise pushed the United States to speed up its own space and science programs.

Context

Sputnik 1 was launched on October 4, 1957, from the Baikonur site in Kazakhstan on an R-7 rocket derived from a Soviet long-range missile. The satellite weighed about 184 pounds (roughly 84 kilograms), far more than the satellites the United States was then preparing, and it circled Earth about every 90 to 96 minutes.

Its radio transmitter could be picked up by amateur radio operators around the world. The batteries ran for a few weeks, and the satellite burned up on re-entry in early January 1958. The launch was timed to the International Geophysical Year, during which both superpowers had announced plans for satellites.

The U.S. reaction was strong. The Vanguard rocket exploded on the pad in December 1957, and Explorer 1 reached orbit on January 31, 1958. Congress and the Eisenhower administration expanded space, missile and science education funding, and NASA was established in 1958. Eisenhower publicly downplayed the launch, but it intensified fears about Soviet missile capability.

Sputnik also carried scientific value beyond the political shock. Tracking its orbit let scientists study the density of the upper atmosphere, and the radio signals gave early data on how radio waves pass through the ionosphere. Its success showed that the rocket used could, in principle, also carry a warhead across continents.