a command equal to that of other Russian military districts took effect on January 1, 2021. The Northern Fleet includes about two-thirds of all the Russian Navy's nuclear-powered ships. The flagship Pyotr Velikiy is named after Peter the Great. The Fleet staged a series of major Barents Sea exercises in January 2004 involving thirteen ships and seven submarines including Pyotr Velikiy, Admiral Kuznetsov, with President Vladimir Putin was aboard the Typhoon class ballistic missile submarine Arkhangelsk. The exercise was marred by two RSM-54 SLBM launch failures aboard Novomoskovsk and Kareliya. Submarines have traditionally been the strongest component of the Northern Fleet. Several new classes of submarines are in production to replace older models including: Borei/Dolgorukiy-class SSBNs, Yasen-class SSGNs, Khabarovsk-class SSGNs and Lada-class conventionally-powered submarines. However, the existing nuclear-powered submarines of the Northern Fleet are also aging rapidly. It is currently unclear whether the new Yasen-class, and other potential follow-on models, can be produced in sufficient numbers, and on a timely basis, to replace aging older nuclear submarines on a one-for-one basis. In this regard, reports suggest that Russian third-generation nuclear submarines have not been modernized to a level to avoid block obsolescence before 2030. The Northern Fleet has also received attention with respect to technological upgrades. The Fleet has received new combat aircraft (deployed within the 45th Air and Air Defence Army), enhanced shore-based missile assets (both surface-to-surface and surface-to-air) as well as new systems such as the Samarkand electronic warfare systems in 2017 and the Barnaul-T air reconnaissance system in December 2021. Samarkand is designed to assess electromagnetic situation, search, detect and analyze radio emissions and Barnaul-T helps conduct reconnaissance round-the-clock. Russia's Northern Fleet in 2018 resumed regular air patrols of the Arctic by long-range anti-submarine aircraft and its share of modern samples of weapons and equipment exceeded 56 percent. An air defense regiment of the Northern fleet armed with S-400 SAM launchers went on combat duty in Novaya Zemlya in the September 2019. Ground force modernization has also been a priority focus through the creation of the 14th Army Corps within the fleet and broader equipment modernization. A tank battalion of a Northern Fleet's separate motorized infantry brigade received the final batch of 26 T-80BVM tanks and completed the rearmament procedure in November 2019. The 76th Guards Air Assault Division and the 98th Guards Airborne Division, strategic reserve formations from the Russian Airborne Forces, might be deployed to