Steel, Aluminum
A 1:10 scale model of the J-2 Bi-propellant Liquid Rocket Engine; the high fidelity model was fabricated within the Marshall Space Flight Center (MSFC) Model Shop to assist engineers during the rocket engine's design and production; itl further served as a training and visualization aid for astronaut crew members, NASA staff, contractors responsible for production and integration of the engines; and the press.
The J-2, a large engie built by Rocketdyne Corporation and producing 232,000 pound of thrust at altitude conditions, burned liquid hydrogen and liquid oxygen to product the necessary high specific impulse for its application on the upper stage of the Saturn V and Saturn IB booster.