This mission was the first joint U.S.–Soviet space flight, and the last flight of an Apollo spacecraft. Its primary purpose was as a symbol of the policy of détente that the two superpowers were pursuing at the time, and marked the end of the Space Race between them that began in 1957. The docking with the US Apollo spacecraft ASTP occurred on July 17, 1975. It was the first docking of two spacecrafts, launched from different nations.