English: This artist's concept depicts the Apollo-Soyuz Test Project (ASTP), the first international docking of the U.S.'s Apollo spacecraft and the U.S.S.R.'s Soyuz spacecraft in space. The objective of the ASTP mission was to provide the basis for a standardized international system for docking of marned spacecraft. The Soyuz spacecraft, with Cosmonauts Alexei Leonov and Valeri Kubasov aboard, was launched from the Baikonur Cosmodrome near Tyuratam in the Kazakh, Soviet Socialist Republic, at 8:20 a.m. (EDT) on July 15, 1975. The Apollo spacecraft, with Astronauts Thomas Stafford, Vance Brand, and Donald Slayton aboard, was launched from Launch Complex 39B, Kennedy Space Center, Florida, at 3:50 p.m. (EDT) on July 15, 1975. The Primary objectives of the ASTP were achieved. They performed spacecraft rendezvous, docking and undocking, conducted intervehicular crew transfer, and demonstrated the interaction of U.S. and U.S.S.R. control centers and spacecraft crews. The mission marked the last use of a Saturn launch vehicle. The Marshall Space Flight Center was responsible for development and sustaining engineering of the Saturn IB launch vehicle during the mission.