Soyuz 19 was a part of the Apollo-Soyuz Test Project, which was the first joint US-Soviet space flight. The Soviet side of mission began on July 15, 1975, 12:20:00 UTC, launching Commander Alexey Leonov and Flight Engineer Valeri Kubasov into orbit. Two days later, they docked with the Apollo spacecraft. American and Soviet crews visited each other's spacecrafts, performed docking and redocking maneuvers, conducted joint scientific experiments, exchanged flags and gifts. Crews spent more than 44 hours together, and after final parting of the ships Soviet crew spent five more days in orbit. Soyuz 19 returned to Earth with a safe landing on July 21, 1975, 10:50:00 UTC.