On January 16, 1969, two crewed spacecraft docked in orbit for the first time.
When the Soviet Union launched the Soyuz 4 spacecraft, only one cosmonaut was on board. But it returned with a crew of three after two cosmonauts from Soyuz 5 transferred spacecrafts in orbit.
Soyuz 4 safely returned to Earth, but the one unlucky cosmonaut who was left behind in Soyuz 5 had a pretty rough landing.
During reentry, the service module failed to separate from the descent module, and the spacecraft got turned upside-down. To top it off, the parachutes and soft-landing rockets failed to deploy properly. That cosmonaut, Boris Volynov, miraculously survived the crash — but he did lose a few teeth.