This medal commemorates the Apollo-Soyuz Test Project, which was the first joint international human spaceflight. The project executed a rendezvous and docking of an American Apollo spacecraft and a Soviet Soyuz spacecraft in July 1975. This particluar medal was struck by a Japanese commercial mint and donated to the Smithsonian after the historic flight.
This object is not on display at the National Air and Space Museum. It is either on loan or in storage.