Cadets from the U.S. Air Force Academy board a KC-135 Stratotanker June 9, 2017, at Beale Air Force Base, California. The cadets were able to watch the tanker refuel F-16C Fighting Falcons from the 388th Fighter Wing at Hill Air Force Base, Utah, 21,000 feet in the air. (U.S. Air Force photo by Airman 1st Class Tristan Viglianco)