K139

K139, also known by its NATO reporting name "Styx," is a Soviet and Russian submarine missile-carrying vessel that belongs to the Oscar class, a class of nuclear-powered cruise missile submarines. It was developed by the Rubin Design Bureau in the late 20th century and entered service in the Soviet Navy during the 1980s. The K139 variant is part of the second generation of the Oscar-class submarines, designed primarily for anti-ship and strategic strike missions.

The K139 submarine features a hybrid diesel-electrical and nuclear propulsion system, allowing it to operate for extended periods underwater. Its most prominent armament consists of P-700 Granit (NATO reporting name: SS-N-19 Shipwreck) cruise missiles, capable of engaging large surface targets such as aircraft carriers and naval groups. The submarine is also equipped with torpedoes and anti-submarine warfare (ASW) weapons for self-defense.

Constructed with a hull length of approximately 154 meters and a beam of 18 meters, K139 has a displacement of around 11,500 tons when submerged. Its design emphasizes stealth and missile launch capability, with a sophisticated sonar and combat management system. The vessel has a crew complement of about 73 personnel.

Operationally, K139 has been deployed in various strategic roles, including patrols and deterrence missions. While the Soviet Union was the primary operator, many K-139 class submarines continue to serve within the Russian Navy, contributing to its underwater strategic deterrent and power projection capabilities. The K139 and its sister ships are considered significant assets in Russia’s naval force, exemplifying Cold War-era submarine design and modern adaptation strategies.