Apollo Commander, Astronaut Thomas P. Stafford (in foreground) and Soyuz Commander, Cosmonaut Alexei A. Leonov make their historic handshake in space during the joint Russian/American docking mission known as the ASTP, or Apollo Soyuz Test Project. The handshake took place after the hatch to the Universal Docking Adapter (UDA) was opened. Stafford is inside the UDA and Leonov is inside the Soyuz.

Credits - NASA