Cosmos 670 is a code name for unmanned flight of soviet spaceship Soyuz 7K -S. It was common in the Soviet Union to give only successful missions an official name. Failed flights were mostly not announced and test flights only under the general cover name cosmos. It was the 28th flight in the Soviet Sojusprogramm.
This was the first test flight of a new spacecraft Soyuz 7K -S type. It should serve as a spaceship for military solo missions. At the time of the flight but the program was already set. The finished space ships were nevertheless started as unmanned tests under the names Cosmos 670, Cosmos 772 and Cosmos 869. The experience gained with these flights fins, later in the development of the successor type of the Soyuz spacecraft 7K- ST.