Image 0 of 5A U.S. Army paratrooper assigned to the 173rd Airborne Brigade stands under the stars during exercise Swift Response 17 in Hohenfels, Germany, Oct. 15, 2017. (Staff Sgt. Alexander C. Henninger/Army) Army 1st Lt. Gerard Holodak, assigned to the 109th Transportation Company, 17th Combat Sustainment Support Battalion, U.S. Army Alaska, fires the M136E1 AT4-CS confined space light anti-armor weapon at Joint Base Elmendorf-Richardson. (Staff Sgt. Westin Warburton/Army) Sailors assigned to the Arleigh Burke-class guided-missile destroyer USS Sampson handle line during a fueling-at-sea with the aircraft carrier USS Theodore Roosevelt. (Mass Communication Specialist 2nd Class Jason Pastrick/Navy) Marine Corps recruit Jorge Pelaez crawls through mud during the final challenge of recruit training, known as the Crucible, at Marine Corps Recruit Depot Parris Island, S.C., Oct. 13, 2017. (Lance Cpl. Devon Burton/Marine Corps) An F-22 Raptor pilot assigned to the 1st Fighter Wing, Joint Base Langley-Eustis, Va., conducts a preflight check at Spangdahlem Air Base, Germany, Oct. 13, 2017. (Staff Sgt. Jonathan Snyder/Air Force)