U.S. Air Force Staff Sgt. Carmen Pontello, 375th Security Forces Squadron military working dog trainer, introduces Hammer to the Ghost Robotics Vision 60 at Scott Air Force Base, Ill., Dec. 17, 2020. (Airman 1st Class Shannon Moorehead/Air Force)A U.S. Air Force F-15E Strike Eagle departs after receiving fuel from a U.S. Air Force KC-135 Stratotanker during an air refueling mission over Southwest Asia, Dec. 22, 2020. (Staff Sgt. Trevor T. McBride/Air Force)A service member participates in an exercise called Operation Wardog Kila for a joint live-fire exercise at Schofield Barracks, Hawaii, Dec. 30, 2020, with the 25th Combat Aviation Brigade, 25th Infantry Division Artillery units and the U.S. Marine Corps. (Sgt. Sarah D. Sangster/Army)Service members participate in an exercise called Operation Wardog Kila for a joint live-fire exercise at Schofield Barracks, Hawaii, Dec. 30, 2020, with the 25th Combat Aviation Brigade, 25th Infantry Division Artillery units and the U.S. Marine Corps. (Sgt. Sarah D. Sangster/Army)Marines debrief their result during Steel Knight 21, Dec. 4, 2020, at Camp Pendleton, Calif. (Lance Cpl. Gustavo Romero/Marine Corps)A U.S. Air Force B-52 Stratofortress departs after receiving fuel from a KC-135 Stratotanker during a multi-day Bomber Task Force mission over Southwest Asia, Dec. 10, 2020. (Staff Sgt. Trevor T. McBride/Air Force)Security forces airmen patrol near a U.S. Air Force B-1B Lancer taxiway at Andersen Air Force Base, Guam, in support of a Bomber Task Force mission, Dec. 26, 2020. (Senior Airman Tristan Day/Air Force)Ensign Chris Luna takes a navigational bearing while standing watch in the pilot house of the guided-missile cruiser USS Princeton (CG 59) on Dec. 21, 2020, in the Indian Ocean. (MC2 Logan C. Kellums/Navy)A U.S. Marine Corps F-35B Lightning II takes off from the amphibious assault ship USS Makin Island (LHD 8) on Dec. 22, 2020, in the Indian Ocean. (MC2 Jacob D. Bergh/Navy)