The USS Southern Cross (NCC-63550) was an Akira-class heavy cruiser active in the late 24th century. (Starfleet International: USS Southern Cross) Southern Cross was commanded by Colonel Bruce O'Brien as of 2384 and deployed to the Starfleet Eleventh Fleet in that year serving as the fleet flagship. The 377th Marine Strike Group ("Thunder From Downunder") was embarked on Southern Cross beginning in 2384.