 Like Salyut 2, it was another Almaz military space station, although unlike its predecessor, it was launched successfully.It was used to test a wide variety of reconnaissance sensors, returning a canister of film for analysis.On 24 January 1975, after the station had been ordered to deorbit, trials of an on-board autocannon (either a 23 mm Nudelman aircraft cannon or its 30 mm counterpart) were conducted with positive results at ranges from 3000 m to 500 m. Cosmonauts have confirmed that a target satellite was destroyed in the test.