This is the solid fuel rocket motor for the Sparrow II air-to-air missile. Produced by the Aerojet-General Corporation, the motor generated 7,800 pounds of thrust for 1.8 seconds, hence its designation 1.8KS7800. The same motor was also used in the Sparrow I and other members of the Sparrow missile family.
The U.S. Navy transferred the Sparrow II to the Smithsonian in 1958.
Transferred from U.S. Navy