Lance Cpl. Riley Crider, a machine gunner assigned to Kilo Company, Battalion Landing Team 3/1, 13th Marine Expeditionary Unit, waits for orders during a fire team maneuver drill while participating in Theater Amphibious Combat Rehearsal (TACR) 18 in Djibuouti. (Cpl. Danny Gonzalez/Marine Corps)Tactical air control party Airmen with the 227th Air Support Operations Squadron, New Jersey Air National Guard, demonstrate a special extraction system while hanging from a UH-60L Black Hawk helicopter assigned to the 1st Assault Helicopter Battalion, New Jersey Army National Guard, during the 2018 Atlantic City International Airshow at Atlantic City, New Jersey, Aug. 22, 2018. (Mark C. Olsen/New Jersey National Guard)Several C-130H Hercules assigned to the 179th Airlift Wing sit on the flightline September 5, 2018, at Mansfield, Ohio, awaiting the mission for the day. (Capt. Paul Stennett/Air National Guard)Electronics Technician 2nd Class Christopher Seul, assigned to Navy Operational Support Center Portland, prepares to hang a scoring target during Navy Region Northwest Reserve Component Command Everett's semi-annual M9 pistol live-fire qualification exercise at Naval Station Everett. (MC1 Kleynia R. McKnight/Navy)Petty Officer 3rd Class Alexander Turla, an airman assigned to the Essex Amphibious Ready Group (ARG), launches an F-35B Lightning II assigned to Marine Fighter Attack Squadron (VMFA) 211, 13th Marine Expeditionary Unit (MEU), aboard the Wasp-class amphibious assault ship USS Essex (LHD 2), Sept. 3, 2018. (Cpl. A. J. Van Fredenberg/Marine Corps)Marines run through CS gas during the hike portion of the 1st Marine Division Super Squad Competition at Marine Corps Base Camp Pendleton, California, Aug. 30, 2018. (Lance Cpl. Audrey M.C. Rampton/Marine Corps)Family members place shoulder boards on Ens. Kevin Barrientos during his commissioning ceremony at Midway Ceremonial Drill Hall at Recruit Training Command (RTC). More than 30,000 recruits graduate annually from the Navy's only boot camp. (MC2 Spencer Fling/Navy)Capt. Andrew 'Dojo' Olson, F-35 Heritage Flight Team pilot and commander, performs a high-speed pass during the Canadian International Air Show in Toronto, Sept. 1, 2018. (Airman 1st Class Alexander Cook/Air Force)Quartermaster 1st Class Dyamonde Metz, from Columbus, Ga., uses a stadimeter on the bridge wing of San Antonio-class amphibious transport dock USS Anchorage during a regularly scheduled deployment of Essex Amphibious Ready Group (ARG) and 13th Marine Expeditionary Unit (MEU). (MC3 Ryan M. Breeden/Navy)Tech. Sgt. Jose Obregon, 347th Operations Support Squadron independent duty medical technician, performs pull ups during a Pre-Ranger Assessment Course, Aug. 24, 2018, at Moody Air Force Base, Georgia. (Senior Airman Greg Nash/Air Force)The Arleigh Burke-class guided-missile destroyer USS Carney (DDG 64) transits the Mediterranean Sea Sept. 4, 2018. Carney, forward-deployed to Rota, Spain, is on its fifth patrol in the U.S. 6th Fleet area of operations in support of regional allies and partners as well as U.S. national security interests in Europe and Africa. (MC1 Ryan U. Kledzik/Navy)Marine Corps Lance Cpl. John Marino, a machine gunner with 1st Marine Regiment, climbs over a log during the obstacle course portion of the 1st Marine Division (MARDIV) Super Squad Competition at Marine Corps Base Camp Pendleton, California, Aug. 30, 2018. (Lance Cpl. Audrey M.C. Rampton/Marine Corps)A Bulgarian Soldier assigned to 61st Mechanized Battalion, throws a training hand-grenade, during a team-building event of a spur ride, Novo Selo Training Area, Sept. 7, 2018. The spur ride is a time-honored cavalry tradition that gives cavalry troops the opportunity to earn silver spurs by participating in a series of physical and mental challenges, which helps create camaraderie and build esprit de corps. (Sgt. Jamar Marcel Pugh/Army National Guard)The Navy Midshipmen take the field before the start of their game against the Memphis Tigers at Navy-Marine Corps Memorial Stadium on September 8, 2018 in Annapolis, Maryland. (Photo by Rob Carr/Getty Images)