FUELING UP Air Force Senior Airman Crystal Cash refuels an F-15 during exercise Vigilant Shield 15 over the United States, Oct. 20, 2014. The annual exercise is designed to integrate Defense Department and civil response in support of the national strategy of aerospace warning and control, defense support of civil authorities and homeland defense. SHARE: Download: Full Size (0.07 MB) Credit: VIRIN: 335488-O-BHW98-156.jpg Photo Gallery