The Space Age began today

On October 4, 1957, the Soviet Union successfully launched Sputnik I (Спутник I) ,the world's first artificial satellite from the Baikonur cosmodrome in Kazakhstan,then part of the Soviet Union. The Russian word "Sputnik" ("Спутник") means literally "travelling companion".
It was a metallic aluminium sphere about 23 inches across (58 cm) weighed only 184 pounds (83,6 kg).It had four antennas that were 2.4-2.9 m long, pointing to one side. Sputnik I travelled an elliptical orbit that took it around the Earth every 96 minutes, at a height of about 150 miles (250 km). It had two radio transmitters (20 and 40 MHz).The radio signals was used to gather information about the electron density of the ionosphere. Temperature and pressure were encoded in the duration of radio beeps, to indicate if the satellite was punctured by a meteorite. It took about 98 minutes to orbit the Earth.
Sputnik I stayed in orbit for only 3 months before falling back to Earth. Its rocket booster, weighing 4 tons, also reached orbit and was easily visible from the ground. Sputnik I was launched by an R-7 rocket. It incinerated upon re-entry on January 3, 1958.