The Minuteman System The Minuteman intercontinental ballistic missile (ICBM) system is part of the U.S. nuclear "triad" of land-based missiles, submarine-based missiles, and strategic bombers. Conceived in the mid-1950s as the first solid-fuel ICBM in the U.S. nuclear arsenal and named for its quick-launch capability, Minuteman became operational on Oct. 22, 1962, at the height of the Cuban Missile Crisis. President John F. Kennedy called the powerful new Minuteman his "ace in the hole" because it was the first U.S. underground silo-launched missile. Solid-fuel Minuteman missiles were simpler to maintain and easier to mass produce than liquid-fuel rockets, and 1,000 were in service by the end of 1967. The USAF has operated four basic Minuteman models, including Minuteman IA, IB, II and III. Each was larger and more capable than the previous models. Arms reduction treaties reduced the force near the end of the Cold War, and after 1995, 500 Minuteman III missiles were the only weapons in the Minuteman system remaining on alert. Minuteman bases or "alert facilities" in several western states covered thousands of acres. All shared common features, including underground facilities similar to the Minuteman II training simulator on display at the museum, and above-ground buildings for maintenance and security. Click here to return to the Minuteman II Mission Procedures Trainer Overview.