At the end of World War II, the United States and the Soviet Union began a decades-long battle for political, military, and technological superiority. In the absence of any real fighting, space exploration provided a focus for the competition between the two superpowers. From the 1950s to the 1970s the United States and the Soviet Union raced to conquer space, but when tensions eased between the two nations in the 1970s, the urgency of winning the race declined and the race ended with the superpowers cooperating on several projects.

Source: Encyclopedia