U.S. Army Command Sgt. Maj. Shelita Taylor, the command sergeant major of the 400th Military Police Battalion, U.S. Army Reserve, dons and clears her gas mask during a team-building ruck march held by the 200th Military Police Command during a 'CSM Huddle' in Scottsdale, Ariz., Sept. 16, 2017. (Master Sgt. Michel Sauret/Army)
Sailors scrub the flight deck aboard USS John C. Stennis (CVN 74) on Sept. 16, 2017, following carrier qualifications in the Pacific Ocean.(MC3 William Ford/Navy)
An F-15E Strike Eagle receives fuel from a KC-135 Stratotanker during a mission over Iraq in support of Operation Inherent Resolve on Sept. 6, 2017. (Staff Sgt. Trevor T. McBride/Air Force)
Marines with Company B, 1st Light Armored Reconnaissance Battalion, 1st Marine Division, hold security in a light armored vehicle during Deep Strike II in the River Valley, Calif., Sept. 12, 2017. (Cpl. Justin Huffty/Marine Corps)
An air commando from the 7th Special Operations Squadron fires a .50 caliber machine gun on Sept. 11, 2017, aboard a CV-22 Osprey during a flight around southern England. (Staff Sgt. Philip Steiner/Air Force)
Green Berets assigned across multiple Special Forces Groups prepare to jump into Tucker Pool at Fort Bragg, N.C., Sept. 6, 2017. They are students in the Maritime Assessment Course, which prepares them for the Combat Diver Qualification Course. (Sgt. Sean L. Williams/Army)
Cadets at the U.S. Coast Guard Academy in New London, Conn., take part in the second Regimental Review of the fall semester, Sept. 15, 2017. (Petty Officer 3rd Class Nicole Foguth/Coast Guard)
Marines with Headquarters and Support Battalion complete their annual gas chamber training on Sept., 13, 2017, at Camp Pendleton, Calif. (Lance Cpl. Brienne Collins Miller/Marine Corps)
Children greet their father on the flightline after his return from supporting Hurricane Harvey relief efforts on Sept. 3, 2017, at Moody Air Force Base, Ga. (Andrea Jenkins/Air Force)
Lance Cpl. Lawrence Gallegos, left, teaches Sgt. Jeffrey Judd about the new Wi-Fi system at Marine Corps Air Station New River, N.C., Sept. 14, 2017. (Lance Cpl. Justin Roux/Marine Corps)
Equipment Operator 3rd Class Samuel Timici, assigned to Explosive Ordnance Disposal Expeditionary Support Unit (EODESU) 2, uses a bar to loosen a strap across equipment, Sept. 7, 2017, onboard Naval Station Norfolk, Va., in preparation to respond to any requests to bolster Northern Command's support of FEMA's assistance in the aftermath of Hurricane Irma. (MC2 Travis DiPerna/Navy)