Planned second long-duration 20 day Voskhod flight. Cancelled in spring 1966 after near-disaster with Voskhod 2 and death of Korolev. A follow-on Voskhod 3V s/n 7 mission was also planned that would have conducted an artificial gravity experiment, unreeling a tether between the Voskhod spacecraft and the Block I final rocket stage.
Planned second crew to the first Almaz space station. Cancelled after the loss of control of Almaz OPS 1 (Salyut 2) in orbit.
On 4 July Soyuz 14 docked with the Salyut 3 space station after 15 revolutions of the earth. The planned experimental program included manned military reconnaissance of the earth's surface, assessing the fundamental value of such observations, and some supplemental medico-biological research. All objectives were successfully completed and the spacecraft was recovered on July 19, 1974 at 12:21 GMT, landing within 2 km of the aim point 140 km SE Dzkezkazgan. After the crew's return research continued in the development of the on-board systems and the principles of remote control of such a station.
Soyuz 15 was to conduct the second phase of manned operations aboard the Salyut 3 military space station, but the Igla rendezvous system failed and no docking was made. The two day flight could only be characterised as '... research in manoeuvring and docking with the OPS in various modes, and development of methods for evacuation and landing from space complex in new conditions....' The crew was recovered on August 28, 1974 20:10 GMT. Officially: Conduct of joint experiments with the Salyut-3 orbital scientific station.