The second Almaz was launched as Salyut 3 on 25 June 1974. Following the successful Soyuz 14 and unsuccessful Soyuz 15 missions, on 23 September 1974 the station ejected a KSI film return capsule, which was recovered damaged but with the film intact. On 25 January 1975 Salyut 3 fired its manoeuvring engines for the last time and braked itself from orbit over the Pacific Ocean.
The station had a planned life of eight months and had the special objective of locating and transmitting to the ground the co-ordinates of mobile objects at sea and in the air. For this purpose 14 type of photo cameras, and various optical sensors (pointing scope, panoramic viewer, periscope) were carried as well as infrared sensors. Semi-active radar (SAR) was not flown but was planned in the future. Salyut 3 was equipped with the Agat-1 camera, which had a 6.375 m focal length using 3 m folding optics, an OD-4 Vzor pointing scope, POU panoramic camera, as well as topographic and star cameras. In addition its Volga infrared apparatus had a 100 m resolution. The Vzor OD-4 could sight an object at sea, then train all of the sensors on that object. Skylab was visually hunted by the station using the Sokol instrument, demonstrating use of the sensor array in space-to-space warfare and reconnaissance.
Of the 17 orbits per day the station would fly, seven did not pass over the USSR and were useless for communication. To fill the gap two tracking ships were used for Salyut 3. The vessel Cosmonaut Yuri Gagarin was stationed off Sable Island in the Atlantic, at 51 deg N, which provided 5 to 6 orbit per day coverage. The ship Cosmonaut Vladimir Komarov was stationed off Cuba, at 21 deg N, and provided coverage on 2 orbits. The result was communications opportunities on every orbit.
The Salyut 3 KSI film capsule was ejected on 23 September 1974 but suffered damage to the landing sequencer from the hot plasma sheath generated during re-entry. Therefore the heat shield did not separate, nor did the main parachute open. The capsule was deformed by the hard landing but all the film was recoverable.
On 24 January 1975 trials of a special system aboard Salyut-3 were carried out with positive results at ranges from 3000 m to 500 m. These were undoubtedly the reported tests of the on-board 23 mm Nudelmann aircraft cannon (other sources say it was a Nudelmann NR-30 30 mm gun). Cosmonauts have confirmed that a target satellite was destroyed in the test.
The next day the station was commanded to retrofire to a destructive re-entry over the Pacific Ocean. Although only one of three planned crews managed to board the station, that crew did complete the first completely successful Soviet space station flight.
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.