150706-N-IP531-024 TIMOR SEA Military Sealift Command Fleet replenishment oiler USNS Rappahannock, center, conducts a replenishment-at-sea with the Arliegh Burke-class guided-missile destroyer USS Mustin, top, and the Nimitz-class aircraft carrier USS George Washington as part of Talisman Sabre 2015. TS15 is a bilateral training exercise intended to maintain a high level of interoperability between U.S. and Australian forces.