Losharik is Russia's one-off Project 10831 / AS-31 nuclear-powered deep-water station built for GUGI special seabed missions rather than conventional attack-submarine combat. Open sources describe a Sevmash-built, Malakhit-designed boat with titanium spherical pressure compartments, host-submarine support, sonar and manipulator-style mission equipment, and a long repair cycle after the fatal July 2019 battery-compartment fire.
RUSI places Losharik among Russia's GUGI special-purpose submarines for seabed warfare and undersea-infrastructure threats, while Reuters and The Barents Observer reported 2024 testing or return-to-service activity after the 2019 fire. Public sources support modern Russian fielding but do not tie AS-31 to one named conflict, so the row remains in the 2015 Various Conflicts holding bucket.
Losharik belongs to the Russian deep-water station line rather than the regular torpedo-armed attack-submarine force. Open sources connect it to GUGI, carrier-submarine operations, and seabed work, while leaving most payload and sortie details classified or disputed.
| Element | Documented context | Catalog note |
|---|---|---|
| Design line | Covert Shores describes Losharik as combining the carrier-borne X-Ray concept with the larger Uniform-style mission scale. | The related    |
| Hull and depth logic | Covert Shores describes joined titanium spherical compartments, while RussianShips gives a 1,000 m operational depth and Gneys-SPE sonar fit. | The pressure-hull arrangement is central to the page because it explains why the boat is a deep-water station, not a normal submarine class. |
| Carrier support | Naval News reported Belgorod as intended to host Losharik; Covert Shores and Russia Military Analysis also discuss BS-64 Podmoskovye and older carrier-submarine context. | No separate catalog record was added for Belgorod or BS-64 in this pass because the source-backed relationship can be explained here without a thin support page. |
| Conflict attribution | RUSI places Losharik in Russia's seabed-warfare capability set, and 2024 reporting describes post-repair testing or return-to-service activity. | Open sources checked in this pass did not identify a named war, strike, loss, or transfer event involving AS-31. |
Losharik is treated in open sources as a single completed Project 10831 boat. The rows below separate reported project-number changes from adjacent GUGI deep-water station families that sources connect to the same design lineage or mission set.
| Variant | Configuration | Designation notes |
|---|---|---|
| Project 10830 | Unrealized modification | RussianShips lists Project 10830 among unrealized modifications associated with the Project 10831 deep-water station program. Sources: Deep-diving nuclear-powered station - Project 10831 |
| Project 1083T | Modernization project | RussianShips describes Project 1083T as a modernization project, but does not list a completed boat under that designation. Sources: Deep-diving nuclear-powered station - Project 10831 |
| Predecessor carrier-borne deep-water station | Covert Shores describes Losharik as combining the carrier-borne concept of Project 1851 X-Ray with the larger Project 1910 / Uniform mission scale. |
| Related GUGI deep-water station family | RUSI groups Paltus with Losharik and other GUGI special-purpose submarines in Russia's seabed-warfare capability set. Sources: Stalking the Seabed: How Russia Targets Critical Undersea Infrastructure |
| Related larger deep-diving station family | Covert Shores treats Project 1910 / Uniform as the larger predecessor whose mission scale Losharik partly inherits, while Naval News discusses AS-15 as a possible stopgap for the Losharik carrier role after the 2019 fire. Sources: Spy Submarine: Russia's AS-31 Losharik, Russia's Gigantic Submarine, Belgorod, Sails For The First Time |
RussianShips and Covert Shores list AS-31 as laid down on 16 July 1990 as a secret special-missions boat.
Sources: Deep-diving nuclear-powered station - Project 10831, Spy Submarine: Russia's AS-31 Losharik
RussianShips lists 5 August 2003 as the AS-31 launch date, while Covert Shores gives an earlier reported launch date, showing the public timeline remains inconsistent.
Sources: Deep-diving nuclear-powered station - Project 10831, Spy Submarine: Russia's AS-31 Losharik
Naval Today, citing the Russian Navy, reported that Project 10831 Kalitka, also known as Losharik, had passed Arctic-condition trials.
Sources: Project 10831 Deep-Sea Nuclear-Powered System Kalitka Passes Trials in Arctic
Russia Military Analysis and The Barents Observer report that a battery-compartment fire killed 14 personnel and sent Losharik into a long repair cycle.
Sources: Fire aboard AS-31 Losharik: Brief Overview, TASS: super-secret nuclear submarine Losharik soon back in service
Naval News reported Belgorod was intended to host Losharik, but that the 2019 accident and unconfirmed AS-15 adaptation reports complicated the carrier-submarine plan.
Sources: Russia's Gigantic Submarine, Belgorod, Sails For The First Time
Reuters, republished by The Star, reported that Losharik would go out for testing in June or July after completing years of repairs.
Sources: Russian nuclear-powered Losharik submarine to be tested in June or July after repairs, TASS reports
