This stamp honors the five astronauts and cosmonauts who participated in the July 1975 Apollo-Soyuz Test Project, the first international joint human spaceflight mission. One of the methods through which governments may attempt to popularize major programs is through the use of stamps. During the nineteenth century and beginning of the twentieth at the end of the Tsarist period, Russian stamps featured exploration projects and the personalities associated with them. In the twentieth century, stamps often featured major development projects and Russian and Soviet scientists and artists. At the dawn of the space age, it was no surprise that the Ministry of Communications (which included Telephone, Telegraph and the Post) chose stamps with themes that honored Soviet activities in space. The Military Attache to the Soviet Embassy in Washington gave this stamp to the Smithsonian in the late 1970s.
This object is not on display at the National Air and Space Museum. It is either on loan or in storage.