1957 - Soviet satellites Sputnik I and II launched
The Soviet Union takes the initiative in the Space Race by launching two satellites into orbit, the second containing Laika, a stray dog.
History was made on October 4, 1957, when the Soviet Union successfully launched Sputnik I. The world's first artificial satellite was about the size of a basketball and weighed only 183 pounds. It took about 98 minutes for Sputnik I to orbit the Earth on its elliptical path. The launch ushered in new political, military, technological, and scientific developments and marked the beginning of the space race between the U.S.and the U.S.S.R.
The Sputnik launch changed everything. As a technical achievement, it caught the world's attention and the Americans off guard. The public reacted with fear that the Soviets' ability to launch such a satellite would translate to the ability to launch ballistic missiles that could carry nuclear weapons from Europe to the U.S.
Then the Soviets struck again: Sputnik II was launched on November 3, carrying a much heavier payload and a dog named Laika (who made it into space but never returned to earth).
The U.S. Defense Department responded to the political and public furor over the Sputnik satellites by approving funding for a U.S. satellite project (which would launch the Explorer satellite on 31 January 1958).The Sputnik launch also led to the creation of NASA, the National Aeronautics and Space Administration in July 1958.
For more information and images check out History0x