The first satellite was the Soviet Union's SPUTNIK, which was launched in 1957. It was the first artificial satellite to be sent into Earth's orbit, and it marked the beginning of the Space Age. SPUTNIK was a metal sphere about the size of a beach ball, and it orbited the Earth for three months before burning up in the atmosphere. Its launch sparked a space race between the United States and the Soviet Union, leading to the development of more advanced satellites and eventually to the first human spaceflight.