Fifty years ago, the soviet union launched into space a 58.5 centimeters and 83 kilos shiny aluminum sphere equipped with 4 long antennas and 2 radio transceivers.

Sputnik-1 (Спутник-1 / Satellite-1), the first artificial satellite, had triggered what would be called later, "the US vs. USSR Space Race". It orbited 1440 times at 250 kms above Earth surface during 3 months transmitting radio signals on 20 & 40 MHz.

This single event launched new political, military, technological, and scientific developments. The Space Era was born.

Sources: Wikipedia, Nasa.