Description
The Novator RK-55 Relief (Russian: РК-55 Рельеф 'Relief'; NATO: SSC-X-4 'Slingshot' ; GRAU: 3K12) is a Russian Navy cruise missile that is launched either from submarines (SLCM) or from surface ships. It can have a nuclear warhead developed in the Soviet Union. A version launched from submarine torpedo tubes, the S-10 Granat ( SS-N-21 'Sampson' ; GRAU: 3K10), has apparently been converted to carry conventional warheads and continues in service to this day. The Russian Federation was reported to have deployed the derivative SS-CX-7/SS-CX-8 systems on 14 February 2017. The land launched version is called the Novator 9M729.
The RK-55 is very similar to the air-launched Kh-55 (AS-15 'Kent') but the Kh-55 has a drop-down turbofan engine and was designed by MKB Raduga. Both have formed the basis of post-Cold-War missiles, in particular the 3M-54 Kalibr which has a supersonic approach phase.