This is a cutaway of the Radiamic liquid-fuel thruster. It was also designed C-1, for Common Engine.
Starting in 1965, it was produced by the Reaction Motors Division of the Thiokol Chemical Corporation as a versatile, small liquid-fuel auxiliary rocket engine adaptable for a number of launch vehicles and spacecraft control systems. It could produce around 80-100 pounds of thrust.
This object was donated to the Smithsonian in 1980 by NASA's Lewis Research Center.
This object is on display in Rockets & Missiles at the Steven F. Udvar-Hazy Center in Chantilly, VA.