Minuteman II: 6, nmi 7, mi; 11, km [ 8 ]. Development of the Minuteman began in the mids when basic research indicated that a solid-fuel rocket motor could stand ready to launch for long periods of time, in contrast to liquid-fueled rockets that required fueling before launch and so might be destroyed in a surprise attack. The Minuteman entered service in as a deterrence weapon that could hit Soviet cities with a second strike and countervalue counterattack if the U.
The Minuteman II entered service in with a host of upgrades to improve its accuracy and survivability in the face of an anti-ballistic missile ABM system the Soviets were known to be developing. By the s, 1, Minuteman missiles were deployed. Warren AFB , Wyoming. Solid fuels were already commonly used in short-range rockets.
Hall's superiors were interested in short- and medium -range missiles with solids, especially for use in Europe where the fast reaction time was an advantage for weapons that might be attacked by Soviet aircraft. But Hall was convinced that they could be used for a true ICBM with a 5,nautical-mile 10, km; 6, mi range. To achieve the required energy, that year Hall began funding research at Boeing and Thiokol into the use of ammonium perchlorate composite propellant.
Adapting a concept developed in the UK , they cast the fuel into large cylinders with a star-shaped hole running along the inner axis. This allowed the fuel to burn along the entire length of the cylinder, rather than just the end as in earlier designs.
The increased burn rate meant increased thrust. This also meant the heat was spread across the entire motor, instead of the end, and because it burned from the inside out it did not reach the wall of the missile fuselage until the fuel was finished burning. In comparison, older designs burned primarily from one end to the other, meaning that at any instant one small section of the fuselage was being subjected to extreme loads and temperatures.
