Sputnik rocket track Long exposure photograph of the night sky showing the track of the rocket that carried Sputnik the worlds first artificial satellite Sputnik was launched on October th by the former Soviet Union The name Sputnik is Russian for travel companion or satellite The body was made from a highly polished aluminium alloy sphere which measured centimetres in diameter and weighed kilograms It also had four long antennas attached Sputnik transmitted radio signals back to earth for a period of days The success of Sputnik prompted the US government to enter the Space Race with the launch of Explorer four months later Photographed on October th