ANDERSEN AIR BASE, Guam --   U.S. Air Force Senior Airman Austin Perry from the 962nd Aircraft Maintenance Unit prepares to marshal an E-3 Sentry from the 961st Airborne Air Control Squadron during annual exercise Cope North Feb. 23, 2017, at Andersen Air Force Base, Guam. The exercise provides opportunities for Airmen from different units and nations to train and work with each other’s airframes. The Sentry has rotating radar that has a range of more than 250 miles, providing early warning and detection for missions. (U.S. Air Force photo by Senior Airman John Linzmeier)