The XLR-87 rocket engine powered the first stage of the two-stage Titan I intercontinental ballistic missile (ICBM). It consists of two side-by-side rocket chambers; the missile's second stage was a one-chamber engine. Both first-and second-stage engines used liquid oxygen and kerosene. This engine produced about 150,000 pounds of thrust from each chamber, or 300,000 pounds total, and was built by the Aerojet General Corporation.

Developed from 1954 as a backup to the Atlas ICBM, the Titan I was intended to help close the "missile gap" with the Soviet Union during the Cold War. It was later replaced by the improved Titan II, that had storable fuels and could be prepared for launch faster. The Titan II also launched the two-man Project Gemini spacecraft. This object was donated to the Smithsonian in 1972 by the U.S. Air Force.