The Apollo-Soyuz Test Project was a joint United States-U.S.S.R. venture to live and work together on a space platform in orbit.
During the cold war, all of us know that America and the Soviet Union were putting the best scientist of there country in the front to develop weapons of mass destruction.
What most don't know is that not only the Russians but the Americans had embedded spies in them to recover weapon specs and also the science between them. In fact, the cold war is known as the golden-age of espionage.