ASTP Anniversary

On this date in 1975, the Apollo-Soyuz Test Project* began.
During this unprecedented mission, U.S. astronauts and Soviet cosmonauts would dock their respective spaceships together and work in peace and harmony.
This mission marks the beginning of when both countries began to pretend we weren't hiding anything from each other. It also marks the last manned US spaceflight until the 1981 maiden voyage of the Space Shuttle.

I suppose my favorite factoid of this mission is the fact that when the Americans would speak to the Russians, they did so in Russian, and each time the Russians spoke to the Americans, it was in English. Tom Stafford welcomed the Soyuz crew after docking with "привет! soyuz, аполлон." ("Hello! Soyuz, Apollo.") Cosmonaut Leonov replied in English "Well done, Tom, it was a good show! We are looking forward now to meeting you in [sic] board Soyuz!"
(Stafford's Okie accent was so pronounced, even when speaking Russian, that Leonov would later joke that three languages were spoken during the ASTP: English, Russian, and Oklahomaski.)
You can hear Leonov's greeting at the end of this video.

*Known as the Soyuz-Apollo Test Project in Russia. Seriously.