Smoke explodes out of the M777A2 lightweight 155 mm howitzer as Marines from Alpha Battery provide indirect fire to units engaged in the mechanized assault course Jan. 31 at Marine Air Ground Combat Center Twentynine Palms during Integrated Training Exercise 2-15. Artillery is used to provide suppressive, indirect fire to ground and air units on the battlefield. The Marines are with Alpha Battery, 1st Battalion, 12th Marine Regiment, currently assigned to 3rd Battalion, 12th Marines, 3rd Marine Division, III Marine Expeditionary Force as part of the ground combat element for Special Purpose Marine Air-Ground Task Force 4 for ITX 2-15. - Smoke explodes out of the M777A2 lightweight 155 mm howitzer as Marines from Alpha Battery provide indirect fire to units engaged in the mechanized assault course Jan. 31 at Marine Air Ground Combat Center Twentynine Palms during Integrated Training Exercise 2-15. Artillery is used to provide suppressive, indirect fire to ground and air units on the battlefield. The Marines are with Alpha Battery, 1st Battalion, 12th Marine Regiment, currently assigned to 3rd Battalion, 12th Marines, 3rd Marine Division, III Marine Expeditionary Force as part of the ground combat element for Special Purpose Marine Air-Ground Task Force 4 for ITX 2-15.