They Put a Working CANNON on a Space Station in 1974 — What It Became 24 Years Later Is INSANE

Salyut 3 was not a Salyut and it was not civilian: it was Almaz, a secret Soviet military space station, and it flew with a working 23mm cannon bolted underneath. The Almaz program ran from 1964 at Vladimir Chelomei's OKB-52 bureau, built as the Soviet answer to the US Air Force's Manned Orbiting Laboratory. Three Almaz stations reached orbit between 1973 and 1976, all of them announced to the world under civilian Salyut numbers to hide what they were: Salyut 2, Salyut 3 and Salyut 5. Salyut 3 carried a Rikhter R-23 autocannon as part of a self-defense system, and on January 24th, 1975, with nobody aboard, ground controllers fired it. It remains the only gun ever fired in space, and the test is still classified. Almost every telling of this Soviet space station story stops at the cannon. The stranger part is what happened to the hardware. The TKS ferry built to service Almaz never once carried a cosmonaut, but its cargo block, the FGB, became the design behind four Mir modules and then Zarya, the first module of the International Space Station, which NASA bought through Boeing for about $220 million and launched in November 1998. A program the Soviet military erased from the record in 1978 is the reason the ISS has a front end. Covered here: the Almaz space station, the Salyut cover story, the space cannon, the TKS spacecraft, and the FGB lineage that runs from a Cold War spy platform to the ISS module Nauka in 2021. Sources: NASA, Zarya module (International Space Station). Zarya built by the Khrunichev State Research and Production Space Center under subcontract to Boeing; described as a US component, "U.S.-funded and Russian-built"; launched November 20, 1998. Wikipedia / Almaz program. "To cover the military nature of the program, the three launched Almaz stations were designated as civilian Salyut space stations." Program development at OKB-52 from 1964; crewed stations ended 1978. RussianSpaceWeb (Anatoly Zak), Almaz OPS-2 / Salyut-3. Three firings of the Shchit self-defense gun conducted January 24, 1975, retrograde, to deorbit the shells. Station deorbited the same day. Soviet government ended crewed station development at Chelomei's TsKBM on June 28, 1978. Wikipedia / TKS spacecraft. "Although extensively flight-tested, no VA ever carried a crew." Four TKS launched 1977 to 1985 under Kosmos designations. FGB design became the basis for Kvant-2 (1989), Kristall (1990), Spektr (1995), Priroda (1996), Zarya (1998) and Nauka (2021). Wikipedia / Salyut 1. "Salyut 1 originated as a modification of the Soviet military's Almaz space station program that was then in development." Wikipedia / Rikhter R-23. 23mm, 23x260mm cartridge, 2,500 rounds per minute, used only in the tail turret of the Tu-22. Space variant carried 32 rounds on Salyut 3. Wikipedia / Manned Orbiting Laboratory. Announced December 10, 1963; canceled June 1969 without any crewed missions flown.