Soyuz 5 was a Soviet space mission launched on January 15, 1969. It was notable for being the first crewed spacecraft to dock with another spacecraft, Soyuz 4, in orbit. The mission lasted for five days, during which the crew conducted various scientific experiments and tests. The crew of Soyuz 5 included cosmonauts Boris Volynov, Viktor Patsayev, and Alexander Serebrov. After successfully completing their mission, they returned to Earth on January 17, 1969. This mission contributed to the development of future space docking techniques and paved the way for later missions in the Soyuz program.