Newtown Square, Pa., native, U.S. Army Sgt. Mark R.

Newtown Square, Pa., native, U.S. Army Sgt. Mark R. Sheafer, an all-wheeled vehicle mechanic from Troop C, 3rd Squadron, 4th Cavalry Regiment, Task Force Raider, 3rd Brigade Combat Team, 25th Infantry Division, Task Force Bronco, with help from an Afghan uniformed policeman changes the oil of an AUP Humvee at Forward Operating Base Shinwar in eastern Afghanistan's Nangarhar province, July 17. Sheafer, on his third combat tour, learned about fixing vehicles from his dad who is a car enthusiast.