But the burning question is... how to modify the sensor suite for Zombie Defense? SOUTH CHINA SEA (May 31, 2012) Rounds are fired from the Phalanx close-in weapons system aboard the U.S. 7th Fleet flagship USS Blue Ridge (LCC 19). The weapons system combines a 20mm Gatling gun with search and tracking radar to provide surface ships with defense against anti-ship missiles. (U.S. Navy photo by Mass Communication Specialist 3rd Class Fidel C. Hart)