Kosmos 772 ( meaning Cosmos 772) was an uncrewed military Soyuz 7K-S test. It was an unsuccessful mission as only one transmitter worked. Only the 166 MHz frequency transmitter operated, all of the other normal Soyuz wavelengths transmitters failed. The experience from these flights were used in the development of the successor program Soyuz spacecraft the Soyuz 7K-ST. Mission parameters Spacecraft: Soyuz 7K-S Mass: 6750 kg Crew: None Launched: September 29, 1975 Landed: October 3, 1975 4:10 UTC Perigee: 154 km Apogee: 245 km Inclination: 51.8 deg Duration: 3.99 days Maneuver Summary 193 km X 270 km orbit to 195 km X 300 km orbit. Delta V: 8 m/s. 196 km X 300 km orbit to 196 km X 328 km orbit. Delta V: 8 m/s. Total Delta V: 16 m/s. See also Soyuz 7K-OK Soyuz TM-25 Cosmos 670 Cosmos 869 References Kosmos 0772 Kosmos 0772 Kosmos 0772 1975 in the Soviet Union Spacecraft launched in 1975