After completion of the three programmed Skylab flights, NASA considered using the remaining backup Saturn IB and Apollo CSM to fly a fourth manned mission to Skylab. It would have been a short 20 day mission - the CSM systems would not have been powered down. Main objective would be to conduct some new scientific experiments and boost Skylab into a higher orbit for later use by the shuttle. The marginal cost of such a mission would have been incredibly low; but NASA was confident that Skylab would stay in orbit until shuttle flights began in 1978 - 1979. But the shuttle was delayed, and faster atmospheric decay than expected resulted in Skylab crashing to earth before the first shuttle mission was flown. References: 431 .

Unmanned Soyuz test flight. Recovered April 13, 1974 5:05 GMT. Soyuz ASTP Test.
Maneuver Summary:
190km X 309km orbit to 190km X 266km orbit. Delta V: 12 m/s
190km X 266km orbit to 240km X 300km orbit. Delta V: 23 m/s
240km X 300km orbit to 258km X 274km orbit. Delta V: 12 m/s
Total Delta V: 47 m/s.
Officially: Investigation of the upper atmosphere and outer space. References: 1 , 2 , 6 .

High resolution photo reconnaissance satellite; returned film capsule; maneuverable. References: 1 , 2 , 6 .

KH-9 type satellite. Space craft engaged in investigation of spaceflight techniques and technology (US Cat A). References: 1 , 2 , 5 , 6 .

Space craft engaged in investigation of spaceflight techniques and technology (US Cat A). References: 1 , 2 , 5 , 6 .

Radar monitoring. References: 1 , 2 , 5 , 6 , 172 .

Area survey photo reconnaissance satellite; returned film capsule; separated capsule (?). References: 1 , 2 , 6 .

High resolution photo reconnaissance mission. References: 279 .

Spacecraft engaged in practical applications and uses of space technology such as weather or communication (US Cat C). References: 1 , 2 , 5 , 6 .

Uncertain if Molniya-1T model was Molniya-1 or Molniya-1T. Operation of a system of long range telephone-telegraph radiocommunication, and transmission of USSR Central Television programmes to the stations of the Orbita network. References: 1 , 2 , 5 , 6 .

Eight satellites launched by a single carrier rocket. References: 1 , 2 , 5 , 6 .

Acquisition of meteorological information needed for use by the weather service. References: 1 , 2 , 6 .

Continued operation of the long-range telephone and telegraph radio-communication system within the Soviet Union and transmission of USSR central television programmes to stations in the Orbita and participating international networks (international coope ration scheme). References: 1 , 2 , 5 , 6 .

High resolution photo reconnaissance satellite; returned film capsule; maneuverable. References: 1 , 2 , 6 .

Investigation of the upper atmosphere and outer space. References: 1 , 2 , 5 , 6 .

Maximum Speed - 930 kph. Maximum Altitude - 15860 m. Flight Time - 419 sec. References: 49 , 97 .

Planned date of fourth manned MOL mission at time of the program cancellation. From the beginning of the project, the Navy had demanded that this be an all-Navy crew, which would limit the crew to Truly, with either Overmeyer or Crippen as co-pilot. References: 128 .

The draft project was drawn up in the first quarter of 1974 and the MO approved the TTZ in May 1974.

Development of the Block Sr for the N1M cancelled; work on the smaller Block R LH2/LOX stage was resumed. This stage was eventually to have been used on the Buran / Vulkan launch vehicles. References: 21 .

The N1 program was cancelled before the next test flight. Mishin was removed as head of NPO Energia. Kozlov is first asked to replace him, but he prefers to stay in Samara. Glushko is appointed as the second choice. Two fully assembled (serial numbers 8L and 9L), and four partially assembled rockets were available at time of cancellation. These would have been the first to use the new modernized series NK-33/NK-39 engines. 8L was planned for launch in the fourth quarter of 1974. Confidence was high that, based on the massive telemetry received on the 7L flight, that all problems would have been rectified. A total of 3.6 billion rubles was spent on the N1-L3 program, of which 2.4 billion rubles went into N1 development. Those on the project felt that they were within months of finally providing the Soviet Union with a heavy-lift booster. Instead the work was discarded, and Glushko began design of the RLA/Vulkan with entirely new configuration and engines. References: 23 , 69 .

Ocean surveillance; nuclear powered. References: 1 , 2 , 5 , 6 .

High resolution photo reconnaissance satellite; returned film capsule; maneuverable. References: 1 , 2 , 6 .

Area survey photo reconnaissance satellite; returned film capsule. References: 1 , 2 , 6 .

Ocean surveillance; nuclear powered. References: 1 , 2 , 5 , 6 .

Investigation of solar ultraviolet rays and X-rays and the earth's upper atmosphere. References: 1 , 2 , 5 , 6 , 99 , 116 .

Synchronous Meteorological Satellite. Spacecraft engaged in practical applications and uses of space technology such as weather or communication (US Cat C). References: 1 , 2 , 5 , 6 .

Ministry of Defence Decree 'On suspension of further launches of the N1' was issued. References: 474 .

Replaced Cosmos 536. Possible ELINT satellite. References: 1 , 2 , 5 , 6 .

Decree 'On formation of NPO Energia' was issued. References: 474 .

First test launch of Yantar second generation reconnaissance spacecraft. References: 42 , 69 .

Maximum Speed - 1212 kph. Maximum Altitude - 17060 m. Flight Time - 448 sec. References: 49 , 97 .

Unmanned test flight of the Soyuz 7K-T(A9) Soyuz variant designed for docking with the military Almaz space station. Recovered May 29, 1974 7:50 GMT. References: 1 , 2 , 6 .

Heavy lunar orbiter. Scientific investigation of the moon and circumlunar space from the orbit of an artificial satellite of the Moon, which was begun by the Luna 19 automatic station. The spacecraft carried imaging cameras and also had the objectives of studying the Moon's magnetic field, surface gamma ray emissions and composition of lunar surface rocks, and the gravitational field, as well as micrometeoroids and cosmic rays. Luna 22 braked into a circular lunar orbit on 2 June 1974. The spacecraft made many orbit adjustments over its 18 month lifetime in order to optimise the operation of various experiments, lowering the perilune to as low as 25 km. Manoeuvring fuel was exhausted on 2 September and the mission was ended in early November. Parameters are for lunar orbit. References: 1 , 2 , 5 , 6 , 67 , 274 , 296 .

Application Technology Satellite; experimental commsat. - Also conducted Cesium ion engine test. References: 1 , 2 , 5 , 6 .

High resolution photo reconnaissance satellite; returned film capsule; maneuverable. References: 1 , 2 , 6 .

Solar wind experiments. Spacecraft engaged in research and exploration of the upper atmosphere or outer space (US Cat B). References: 1 , 2 , 5 , 6 .

Start structural assembly crew module, Enterprise (OV-101) References: 15 .

Area survey photo reconnaissance satellite; returned film capsule. References: 1 , 2 , 6 .

KH-8 type satellite. Space craft engaged in investigation of spaceflight techniques and technology (US Cat A). References: 1 , 2 , 5 , 6 .

High resolution photo reconnaissance satellite; returned film capsule; maneuverable. References: 1 , 2 , 6 .

Maximum Speed - 1303 kph. Maximum Altitude - 19970 m. Flight Time - 405 sec. References: 49 , 97 .

Radar calibration mission. References: 1 , 2 , 5 , 6 .

Possible ELINT satellite. References: 1 , 2 , 5 , 6 .

Military-Industrial Commission (VPK) Decree 'On establishment of the State Commission for testing the Soyuz-T' was issued. A State Commission was formed to oversee the flight tests of the solo mission 7K-S. The draft design for 7K-ST space station transport version was completed in August 1974.

Energia Decree 'On suspension of work on the N1 -L3' was issued. References: 474 .

First successful Almaz military manned space station flight. Following the successful Soyuz 14 and unsuccessful Soyuz 15 missions, on 23 September 1974 the station ejected a film return capsule, which was successfully recovered. On 25 January 1975 it fired its manoeuvring engines for the last time and braked itself from orbit over the Pacific Ocean.
Maneuver Summary:
208km X 240km orbit to 213km X 253km orbit. Delta V: 4 m/s
213km X 252km orbit to 251km X 268km orbit. Delta V: 15 m/s
250km X 266km orbit to 265km X 271km orbit. Delta V: 5 m/s
266km X 267km orbit to 268km X 272km orbit. Delta V: 1 m/s
265km X 269km orbit to 265km X 273km orbit. Delta V: 1 m/s
261km X 266km orbit to 258km X 262km orbit. Delta V: 1 m/s
258km X 261km orbit to 258km X 286km orbit. Delta V: 7 m/s
235km X 259km orbit to 261km X 285km orbit. Delta V: 14 m/s
261km X 285km orbit to 255km X 294km orbit. Delta V: 3 m/s
218km X 229km orbit to 0km X 218km orbit. Delta V: 68 m/s
Total Delta V: 51/119 m/s.
Officially: Futher testing of improved station design, on-board systems and equipment; conduct of scientific and technical research and experiments in space flight. Futher testing of improved station design, on-board systems and equipment; conduct of scientific and technical research and experiments in space flight. References: 1 , 2 , 5 , 6 , 67 , 274 .

Investigation of the upper atmosphere and outer space. References: 1 , 2 , 5 , 6 , 99 .

Military navigation satellite. References: 1 , 2 , 5 , 6 .

Maximum Speed - 1480 kph. Maximum Altitude - 20770 m. Flight Time - 427 sec. References: 49 , 97 .

Military topography satellite; returned film capsule; separated science capsule. References: 1 , 2 , 6 .

Covered Oko constellation plane 2 - 315 degree longitude of ascending node. References: 1 , 2 , 5 , 6 , 100 .

Glushko supports modest project to do subsonic flight tests of Spiral orbiter configuration. References: 83 .