R-39 Rif

The R-39 Rif (NATO reporting name: SS-N-20 Sturgeon; bilateral arms control designation: RSM-52 ) was a submarine-launched ballistic missile (SLBM) that served with the Soviet Navy from its introduction in 1983 until 1991, after which it served with the Russian Navy until 2004. The missile had GRAU indices of 3M65, 3M20, and 3R65. It was carried on board Typhoon class submarines.

An intercontinental missile, the R-39 had a three-stage solid-fuel boost design with a liquid-fuel post-boost unit carrying up to ten MIRV warheads. Like other SLBMs the initial launch was powered by a gas generator in the bottom of the firing tube. During the missile's passage through the water additional motors produce a gaseous wall around the missile, reducing hydrodynamic resistance. The launch system was designated "D-19".