The RPK-2 Vyuga (Russian: РПК-2 Вьюга, blizzard; NATO reporting name: SS-N-15 Starfish), also designated as 81R, is a Soviet submarine-launched, nuclear-armed anti-submarine missile system, launched exclusively through 533-millimetre (21.0 in) torpedo tubes.

Analogous to the SUBROC missile previously used by the US Navy, it is designed to be fired from a 533 mm torpedo tube.

It is boosted by a choice of mechanisms depending on model before clearing the water, firing a solid fuel rocket and delivering its payload up to 45 kilometres (28 mi) away.

The submarine-launched versions are used by the Akula, Oscar, Typhoon, Delta, Kilo, and Borei classes.

However, the munition package used in either is identical and hence the ship-launched version is launched into the water and submerges before firing its engines.