Sputnik was the first satellite to launch and successfully orbit the Earth. It was launched on October 4, 1957 by the Soviet Union. Sputnik weighed 183.9 pounds and was able to complete an orbit around the Earth in 98 minutes. 

The launch of Sputnik by the Soviet Union created a great deal of fear in the United States. Americans were afraid that the launch of Sputnik would lead to the Soviet Union being able to develop and launch nuclear weapons that could reach the United States. 

The launch of Sputnik marked the beginning of both the space age and the space race between the United States and the Soviet Union. After the launch of Sputnik, the United States began to accelerate its space program. This led to the establishment of the National Aeronautics and Space Administration (NASA) in 1958 and to man's first steps on the moon on July 21, 1969.