Apollo-Soyuz mission was successful in 1975. Three American astronauts, Thomas P. Stafford, Vance D. Brand, and Donald K. Sayton, from Apollo 18 docked and worked with two Soviet cosmonauts, Alexey Leonov and Valeri Kubasov, on the Soyuz 19 craft. The purpose of the mission was to show that the space race was over and that different countries could work together to forward space exploration. The mission concluded on July 21, 1975. Children can learn more at: Apollo-Soyuz.