Minuteman 1 ICBM Air Launch

The Boeing Minuteman was the first ICBM in the world to use solid-fuel rather than liquid-fuel rocket motors, thus it ushered in the second generation of ICBMs. It was smaller and easier to maintain than the first-generation Atlas and Titan ICBMs, and because of its solid propellant could be launched almost instantaneously. Today, almost forty years since the first example became operational, the missile is still the primary ICBM in the nuclear arsenal of the United States. Research into solid-fueled ICBMs dates back to World War II, but early solid-propellant rocket motors were not sufficiently advanced to allow great success. However, in January 1955, amidst the development of the liquid-fueled Atlas and Titan missile systems, funding was made available for investigation of alternative ICBM designs. The USAF Western Development Division immediately initiated a feasibility study into solid-propellant rocket motors for use on ICBMs and by mid-1957 the secret development of a vehicle called "Missile Q" was underway. The new ICBM would soon become known as the Minuteman. Read more at http://www.hill.af.mil/library/factsheets/factsheet.asp?id=5718