Spying between the nations took advantages of improvements in space technology. First both the United States and Soviet Union developed intercontinental ballistic missiles (ICBMs) to shoot each other with nuclear arms. Then the Soviet Union launched the first unmanned satellite, known as Sputnik I, into outer space in 1957. This greatly alarmed Americans, and the United States responded by launching its own satellite in 1958 and later initiating a mission to land on the Moon. | Spying between the nations took advantages of improvements in space technology. First both the United States and Soviet Union developed intercontinental ballistic missiles (ICBMs) to shoot each other with nuclear arms. Then the Soviet Union launched the first unmanned satellite, known as Sputnik I, into outer space in 1957. This greatly alarmed Americans, and the United States responded by launching its own satellite in 1958 and later initiating a mission to land on the Moon. |