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 What to know about Tricare costs and changes as open season starts 2024-11-15 How the Army’s first Hispanic 4-star distinguished himself in 2 wars 2025-01-23 Key Senate confirmation moves follow Trump’s inauguration 2025-01-21 Region East COC [Image 3 of 15] 2024-11-04