Sputnik 1 satellite, 1957.

RUSSIA - NOVEMBER 09: Replica. Launched on October 4th, 1957, Sputnik 1 was the first successfully launched artificial satellite. It weighed 83.8kg (184 lb), orbited the Earth every 98 minutes, and carried two radio transmitters with which it informed the world of its presence in orbit by means of a series of beeps. The launch of Sputnik effectively began the space race between the Soviet Union and the United States, which culminated in the Americans landing on the Moon 12 years later. Apart from both sides in the Cold War using space exploration as a vehicle for proving the superiority of their respective ideologies, there was also a deep-rooted fear on either side that the ?enemy? could gain a decisive military advantage through space technology. (Photo by SSPL/Getty Images)