Apollo Service Module Propulsion System


Display Status:

This object is on display in the Human Spaceflight exhibition at the Steven F. Udvar-Hazy Center in Chantilly, VA.

Collection Item Summary:

This is a cutaway of the combustion chamber of the Apollo Service Module Propulsion System (SPS), a liquid-fuel rocket engine used on Apollo spacecraft. It is not shown with its larger adjoining nozzle. Apollo astronauts used the SPS to steer the spacecraft toward the Moon, place it into lunar orbit, and propel it back toward Earth.

Using storable propellants, the SPS produced a thrust of 21,900 pounds for a minimum of 0.4 seconds or up to 12.5 minutes, as required. The SPS engine served successfully on all Apollo missions, including the Apollo-Soyuz Test Project in 1975. This object was donated to the Smithsonian in 1986 by the NASA Johnson Space Flight Center.

Collection Item Long Description:

Inventory Number


Credit Line

Transferred from the National Aeronautics and Space Administration


Country of Origin

United States of America


  • Combustion chamber, rubberized, phenolic refrasil inner liner, an ablative or heat-resistant material. Aluminum flange bonded to inner liner. Propellant lines, 304L stainless steel. Valves, cast aluminum. Injector, Type 6061-T6 aluminum alloy. Other parts, stainless steel; fixture brackets, steel.
  • Aluminum, Stainless Steel, Paint, Plastic, Paper, Adhesive, Ink, Synthetic Fabric


Overall: 5 ft. 3 in. tall x 4 ft. 5 in. wide, 3850 lb. (160.02 x 134.62cm, 1746.3kg)

Data Source

National Air and Space Museum

Restrictions & Rights

Do not reproduce without permission from the Smithsonian Institution, National Air and Space Museum


PROPULSION-Rocket Engines