Airmen perform a high altitude, low oxygen jump over Washington state, Aug. 7, 2017, during exercise Mobility Guardian. (Senior Airman Clayton Cupit/Air Force)
Marines with the Expeditionary Firefighting and Rescue team for Marine Wing Support Squadron 272, put out a fire as part of a drill aboard the Combat Center during Integrated Training Exercise 5-17, July 29, 2017. (Cpl. Medina Ayala-Lo/Marine Corps)
German Army Cpl. Vadim Ganshi, assigned to 2nd Company, Infantry Battalion 291, French German Brigade, fires a Panzerfaust 3. Vaziani, Republic of Georgia, Aug. 5, 2017. (Spc. Hayley Gardner/Army)
Sailors load a missile into an F/A-18E Super Hornet aboard the USS Nimitz in the Persian Gulf, Aug. 8, 2017. (Petty Officer 3rd Class Weston A. Mohr/Navy)
Lance Cpl. Kyle Hollenback, 1st Battalion, 1st Marine Regiment, loads while Pfc. Sean Carlson, 1/1, stabilizes the stand during an individual training exercise at Range 410A aboard the Marine Corps Air Ground Combat Center, Twentynine Palms, Calif. (Pfc. Margaret Gale/Marine Corps)
Army Spc. Ridwan Salaudeen climbs through a confined space during Combat Support Training Exercise 86-17-02 at Fort McCoy, Wis., Aug. 9, 2017. (Spc. John Russell/Army)
Corporal Jarris Wade, number one rifle inspector, U.S. Marine Corps Silent Drill Platoon, executes a rifle inspection during the Staff Noncommissioned Officer Evening Parade at Marine Barracks Washington D.C., Aug. 4, 2017. (Cpl. Robert Knapp/Marine Corps)
Sailors assigned to Explosive Ordnance Disposal Mobile Unit (EODMU) 2 and Expeditionary Mine Countermeasures Company (ExMCM Co.) 202, attach tow lines to a Mark 18 Mod. 2 Unmanned Underwater Vehicle (UUV) on Aug. 4, 2017, during an ExMCM training exercise. (MC2 Charles Oki/Navy)
Paratroopers from U.S. Army Alaska's 4th Brigade Combat Team (Airborne), 25th Infantry Division conduct Hollywood jumps at Joint Base Elmendorf-Richardson, Alaska, July 27, 2017. (U.S. Army photo)
Defense Secretary Jim Mattis speaks with crew members from the Navy's Ohio-class ballistic-missile submarine USS Kentucky at Naval Base Kitsap in Bangor, Wash., Aug. 9, 2017. (Staff Sgt. Jette Carr/DoD)
