The M157 Self-Propelled Mobile Artillery was a Indirect Fire weapon system, fielded by the UNSC Army and Marine Corps, beginning 2561.
The M157 Self-Propelled Mobile Artillery vehicle was designed to be fast and mobile, yet able fire 155mm projectiles at ranges up to 58 miles. The vehicle was commanded by a crew of three, and held 32 155mm projectiles internally. The M157 SPMA was intended to working in sections of 4 to 7 other indirect fire units, to provide effective artillery fire.
The vehicle was defended by a single Model 60 Machine Gun, in a turret on the Vehicle Commander's hatch. The vehicle was surrounded by 4 inch thick armor of biosteel and titanium.