Rocket Motor, Solid Fuel, Marc 50, Minuteman III Nosecone Ejection Motor


Display Status:

This object is on display in the Rockets and Missiles exhibition at the Steven F. Udvar-Hazy Center in Chantilly, VA.

Collection Item Summary:

This is a Marc 50 rocket motor developed and manufactured by the Atlantic Research Corporation (ARC). The U.S. Air Force used these motors to eject the nosecone shroud on the Minuteman III intercontininental ballistic missile (ICBM) just before deployment of the Mark 12 reentry vehicle that would carry the nuclear payload.

The motor used Arcadene 156A propellant manufactured by ARC; it produced a thrust of 1,100 pounds. Development of the motor got underway in August 1966 and ended in a little more than one year, in September 1967. The Minuteman III became operational in 1970.

Transferred to NASM from the Atlantic Research Corporation.

Collection Item Long Description:



Inventory Number


Credit Line

Gift of Atlantic Research Group

Country of Origin

United States of America


Overall, steel, probably AISI 4130 steel, with an ATJ graphite nozzle insert; exterior seruces are cadmium plated


Length, 19 inches; width, 17 inches; diameter, 6 inches; weight, 12 lbs.

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

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