RK-55

The RK-55 Relief is a Russian cruise missile developed by NPO Novator that can be launched from submarines or from surface ships, and it can carry a nuclear warhead. NATO calls the ground-launched version SSC-X-4 Slingshot, and the submarine torpedo-tube version, the S-10 Granat, is known to NATO as SS-N-21 Sampson. The missile is very similar to the air-launched Kh-55 designed by Raduga, and both became the basis of later weapons such as the Kalibr family. The RK-55 first flew in 1976, and fewer than a hundred had been deployed by the end of 1988, first on Akula-class submarines. Later boats of the Sierra and Victor III classes and the Yasen class also received it. After arms-control limits on sea-launched nuclear cruise missiles, the S-10 appears to have been converted to carry conventional warheads and remains in service.