A Finnish Air Force F/A-18 Hornet conducts an aerial refueling mission over Finland with a U.S. Air Force KC-135 Stratotanker assigned to RAF Mildenhall, England, May 25, 2017. Both aircraft participated in Arctic Challenge 2017, a multinational exercise encompassing 11 nations and more than 100 aircraft. (U.S. Air Force photo by Tech. Sgt. David Dobrydney)