On October 4, 1957, Moscow declared one of its greatest ever triumphs: in a brief radio telegram, the state wires service Tass announced the first successful launch of an artificial satellite into the Earth’s orbit.

The Soviet republics were informed that the ball-shaped Sputnik I—58 centimetres (22 inches) in diameter and 83.6 kilograms (141 pounds) in weight—was orbiting at a speed of 8,000 meters per second. 

“The Russians have won the race. The entire world is following the satellite’s flight around the Earth,” Communist Party mouthpiece Pravda declared. “Honor and glory to the Soviet workers in science and technology.”