Soyuz 5 (Russian: Союз 5, Union 5) was a Soyuz mission using the Soyuz 7K-OK spacecraft launched by the Soviet Union on 15 January 1969, which docked with Soyuz 4 in orbit. It was the first-ever docking of two manned spacecraft of any nation, and the first-ever transfer of crew from one space vehicle to another of any nation, the only time a transfer was accomplished with a space walk – two months before the US Apollo 9 mission performed the first ever internal crew transfer.