JOINT BASE PEARL HARBOR-HICKAM (July 31, 2021) The Los Angeles-class fast-attack submarine USS Chicago (SSN 721) departs Joint Base Pearl Harbor-Hickam for Large-Scale Exercise (LSE) 2021. LSE 2021 is a live, virtual, and constructive, scenario-driven, globally integrated exercise that will provide high-end training at sea and ashore. (U.S. Navy photo by Mass Communication Specialist Chief Amanda Gray)