181209-M-ZD670-084 CAMP PENDLETON, Calif. (Dec. 9, 2018) 1st Lt. Eric Satterthwaite, training officer of the 7th Engineer Support Battalion, attaches a hose onto a 3D concrete printer during 7th ESB’s 3D concrete printing exercise at Camp Pendleton, Calif., Dec. 9, 2018. 7th ESB’s mission is to utilize the Automated Construction of Expeditionary Structures (ACES) printer to conduct 3D concrete printing and evaluate emerging technology for future application in Marine Corps engineering operations. (U.S. Marine Corps photo by Lance Cpl. Betzabeth Y. Galvan/Released)