Final month, a Russian military show, Voennaya Priemka, revealed a single of the greatest secrets of the Soviet Union’s 1970s space program: the R-23M Space Cannon. A defensive weapon created to counter the threat of American anti-satellite weapons, the R-23M was a 23-millimeter automatic cannon that could be fired in the vacuum of space.
Making use of footage from the show, Anatoly Zak, of RussianSPaceWeb.com, and other people had been able to produce a 3-dimensional model of the R-23M, published yesterday by Popular Mechanics. Fired only after in its lifetime—just as the space station carrying it was preparing to be decommissioned by means of a fiery re-entry—the R-23M served aboard 3 Almaz Orbital Piloted Stations (OPS). The Almaz plan, originally undertaken in the 1960s as a objective-constructed military reconnaissance space station with a reusable crew return module, was folded into the Salyut plan in the 1970s.
The R-23M was based on the tail gun of the Tupolev Tu-22 “Blinder” bomber. It weighed 37 pounds and had a fire rate of above 950 rounds per minute, Zak reported, “blasting 200-gram shells at a velocity of 690 meters per second (1,500 miles per hour). According to veterans of the Almaz project, the space cannon effectively pierced a metal gasoline canister from a mile away in the course of its ground tests.”