Apollo–Soyuz

Apollo–Soyuz was the first crewed international space mission, carried out jointly by the United States and the Soviet Union in July 1975. Millions of people around the world watched on television as an American Apollo spacecraft docked with a Soviet Soyuz capsule. The project, and its "handshake" in space, was a symbol of détente between the two superpowers amid the Cold War.

The Americans officially called the mission the Apollo–Soyuz Test Project (ASTP) while the Soviets called it Experimental flight "Soyuz"–"Apollo" (Russian: Экспериментальный полёт «Союз»–«Аполлон», romanized: Eksperimentalniy polyot "Soyuz"–"Apollon") and Soyuz 19. The unnumbered American spacecraft was left over from canceled Apollo missions and was the last Apollo module to fly.

The mission consisted of three American astronauts (Thomas P. Stafford, Vance D. Brand, and Deke Slayton) and two Soviet cosmonauts (Alexei Leonov and Valery Kubasov) who performed both joint and separate scientific experiments, including an arranged eclipse of the Sun by the Apollo module to allow instruments on the Soyuz to take photographs of the solar corona. The pre-flight work provided useful experience for later joint American–Russian space flights, such as the Shuttle–Mir program and the International Space Station.

Apollo–Soyuz was the last crewed United States spaceflight for nearly six years until the first launch of the Space Shuttle on 12 April 1981, and the last crewed United States spaceflight in a space capsule until Crew Dragon Demo-2 on 30 May 2020.