Russia's massive nuclear-powered battlecruiser Admiral Nakhimov is nearing a return to frontline service after undergoing one of the most extensive warship modernizations in modern naval history. The vessel, which recently entered the final phase of sea trials, sailed under its own power for the first time in 28 years following a lengthy overhaul that upgraded its sensors, electronics, command systems, and missile arsenal. At 28,000 tons, Admiral Nakhimov is the world's largest nuclear-powered surface combatant. Originally built during the Soviet era as part of the Kirov-class battlecruiser program, the ship was designed for long-duration operations in extreme Arctic conditions and is expected to become a cornerstone of Russia's Northern Fleet.