R-29RM Shtil

The R-29RM Shtil (Russian: Штиль, lit. "Calmness", NATO reporting name SS-N-23 Skiff) was a liquid propellant, submarine-launched ballistic missile in use by the Russian Navy. It had the alternate Russian designations RSM-54 and GRAU index 3M27. It was designed to be launched from the Delta IV submarine, each of which is capable of carrying 16 missiles. The R-29RM could carry four 100 kiloton warheads and had a range of about 8500 km. They were replaced with the newer R-29RMU2 Sineva and later with the enhanced variant R-29RMU2.1 Layner.

Development
Development of the R-29RM started in 1979 at the Makeyev Rocket Design Bureau. The navy accepted the armament in 1986 and subsequently installed the D-9RM launch system consisting of a cluster of 16 R-29RM on board the nuclear-propelled Project 667BDRM submarines.

Operation Behemoth
On 6 August 1991 at 21:09, K-407 RUSSIAN SUBMARINE Novomoskovsk, under the command of Captain Second Rank Sergey Yegorov, became the world's only submarine to successfully launch an all-missile salvo, launching 16 R-29RM (RSM-54) ballistic missiles of the total weight of almost 700 tons in 244 seconds (operation code name "Behemoth-2"). All the missile hit their designated targets at the Kura Missile Test Range in Kamchatka.

Space Launch Vehicle
Several R-29RM were retrofitted as Shtill carrier rockets to be launched by Delta-class submarines, the submarines being mobile can send a payload directly into a heliosynchronic orbit, notably used by imaging satellites. Outside the confines of the Russian military, this capability has been used commercially to place three out of four microsatellites into a low Earth orbit with one cancellation assigned to the Baikonur Cosmodrome for better financial terms.

End of service
The last boat carrying R-29RM, K-51 RUSSIAN SUBMARINE Verkhoturye, went into refit to be rearmed with the newer R-29RMU Sineva on 23 August 2010.

Former operators

 * Russian Navy (1992-2010)
 * Soviet Navy (1986-1991)
 * Soviet Navy (1986-1991)
 * Soviet Navy (1986-1991)