PNSY Successfully Undocks Cheyenne 2025-02-10 Comments Closed News, RSS KITTERY, Maine — The Los Angeles improved-class attack submarine USS Cheyenne (SSN 773) was successfully undocked Feb. 6, marking a significant milestone in its service life extension program at Portsmouth Naval Shipyard. Related Items Veterans urge Americans against political violence ahead of election 2024-10-23 New aircraft carriers face years of delivery delays 2025-07-09 USS New York, USS Oak Hill to Participate in Fleet Week New York 2025 2025-04-24 NASCAR Will Hold First Street Race on Active Military Base at Naval Base Coronado in 2026 2025-07-23