Image: NASA History Office.

On this date in 1975, an American Apollo spacecraft and a Russian Soyuz spacecraft dock in Earth orbit, and members of both crews shake hands in space for the first time. With Soviet-American detente crumbling, however, this flight, known as the Apollo/Soyuz Test Project (ASTP), will be the last such docking for another 20 years. More information about ASTP can be found on the Astronautix website here.