KENNEDY SPACE CENTER, FLA. - John Macke (standing, left), with Boeing St. Louis, Alden Pitard (seated, left) and Dan Clark (right), with KSC Boeing, look at a monitor after 3D digital scanning of actuators in the Orbiter Processing Facility. There are two actuators per engine on the Shuttle, one f

Credit lineKENNEDY SPACE CENTER, FLA. - John Macke (standing, left), with Boeing St. Louis, Alden Pitard (seated, left) and Dan Clark (right), with KSC Boeing, look at a monitor after 3D digital scanning of actuators in the Orbiter Processing Facility. There are two actuators per engine on the Shuttle, one for pitch motion and one for yaw motion. The Space Shuttle Main Engine hydraulic servoactuators are used to gimbal the main engine.. NASA/KSC, 2003-09-03. Public domain. ID: KSC-03pd2509.