The Decision to Launch

In the mid-1950s, the United States and the Soviet Union were racing to launch the first artificial satellite as part of the International Geophysical Year of 1957–1958. A Soviet team led by Sergei Korolev decided to use the R-7 launcher, originally developed as an intercontinental ballistic missile, to place a simple satellite into orbit before the United States could do so.

The original Soviet plan called for a more complex scientific satellite, "Object D," but its development was falling behind schedule. Korolev therefore pushed through the launch of a much simpler "Simplest Satellite" (PS-1) — a metal sphere with no scientific instruments, whose sole purpose was to transmit a radio signal and demonstrate that the USSR was capable of delivering a payload into orbit.

The satellite was built and tested in a record time of just a few weeks.