 In 1988, Vice Admiral Diego E. Hernandez as Commander, Third Fleet, coordinated RIMPAC '88, a massive naval exercise which included more than 40 ships, approximately 200 aircraft and more than 50,000 sailors, airmen and Marines from the United States, Japan, Australia and Canada.This exercise marked the first inclusion of a battleship, USS "Missouri", as a component in RIMPAC.His last assignment on active duty was as Deputy Commander in Chief U.S. Space Command, dual hatted as Vice Commander, North American Aerospace Defense Command.