Launch from the Launch Complex

On October 4, 1957, at 19:28 UTC, an R-7 rocket carrying Sputnik 1 lifted off from the Tyuratam launch site (present-day Baikonur). Less than five minutes later, the satellite separated from the launcher and entered an elliptical orbit around Earth.

Sputnik 1 was a polished aluminum sphere 58 centimeters in diameter and weighing 83.6 kilograms, fitted with four whip antennas and two radio transmitters.

Shortly after reaching orbit, ground stations picked up its characteristic "beeping" on frequencies of 20.005 and 40.002 MHz — a signal that radio amateurs around the world could also receive.