U.S. Air Force aircraft maintainers with the 513th Air Control Group rest before working to launch an E-3 Sentry aircraft July 20, 2014, at Joint Base Pearl Harbor-Hickam, Hawaii, during Rim of the Pacific 2014. RIMPAC is a U.S. Pacific Fleet-hosted biennial multinational maritime exercise designed to foster and sustain international cooperation on the security of the world?s oceans.