FlightGlobal.com
Home
Premium
Archive
Video
Images
Forum
Atlas
Blogs
Jobs
Shop
RSS
Email Newsletters
You are in:
Home
Aviation History
1964
1964 - 1958.PDF
FLIGHT International, 25 June 1964 1079 Missiles and Spaceflight IMPROVED MINUTEMEN The story of the Minuteman second-generation ICBM of the US Air Force is primarily one of outstanding success, and of the better- ment of challenging schedules for R&D and operational deployment. These aspects were outlined in great detail in this journal's issue dated November 14,1963. Nevertheless, in the matter of operational range the original Minuteman fell well short of the original specifi- cation, and this fact—which has long been common knowledge in US defence circles—has now been confirmed by Dr Alain C. Enthoven, Deputy Assistant Secretary of Defense (Systems Analysis). Design range of the Minuteman weapon system has always been 5,500 n.m. (6,333 miles), the same as that of the first-generation Atlas and Titan. The earlier liquid-propellant ICBMs surpassed this range target by a considerable margin, but the first type of Minuteman to go into production, LGM-30A (L signifying hardened silo emplacement, G denoting that the target is on the ground, and M standing for "Missile"), is believed to have a range not greater than 4,500 n.m. On a visit to missile emplacement A-I, of the 341st Wing of Strategic Air Command at Malmstrom AFB, Montana (Wing I), we were told that the distance from that silo "to the Kremlin" was just 4,432 n.m.; and, although we did not report the fact at the time, it was clear that the ability of LGM-30A to fly such a mission was marginal. LGM-30A is found only at Wing I at Malmstrom, the 150 silos of which are dispersed across much of the 146,000 sq miles of Montana state. Wings II to V are equipped with the LGM-30B, which incorporates numerous differences aimed at increasing range, payload and accuracy. Superficial modifications include removal of the first-stage skirt, a lengthening of the guidance and control section (despite the adoption of a smaller, solid-state digital computer) and a change in re-entry vehicle to the more advanced Avco Mk 11. Less obvious is the fact that the second-stage motor case is fabricated in titanium alloy instead of steel. LGM-30B has since last autumn been in production at the USAF facility operated by the Aero-Space Division of the Boeing Company, the system assembly and test integrator. A considerably greater advance is represented by the improved Weapon System 133B, the vehicle portion of which is LGM-30F (previously known as LGM-30C). According to Boeing, "F-model Minuteman silo launch at Vandenberg AFB, Calif, down the Western Test Range on November 13, 1963, by the 6555th Aerospace Test Wing, US Air Force. The LGM-30A is about to overtake its smoke ring specifications read like a hard-sell advertising copywriter's dream: greater range and payload, greater accuracy and increased surviv- ability." LGM-30F is often loosely referred to as "Minuteman II." Outwardly the F model is distinguished principally by its sub- stantially greater length, and by the slightly increased diameter of the second stage. This larger second-stage motor is entirely new, and instead of having four exits with gimbal-mounted nozzles it has a single nozzle with liquid-injection TVC (thrust-vector control). The TVC injectant is Freon, the same fluid as that chosen by Lockheed Missiles & Space Co for the same application in Polaris A-3. Injection of Freon into the main gas stream at the nozzle throat creates a shock wave, pressure field and momentum- transfer which deflects the main thrust vector to the degree required to control the vehicle. Equipment for the TVC consists of two units mounted on opposite MINUTEMAN MISSILES Weapon system WS-I33A WS-133A WS-133B Missile type LGM-30A LGM-30B do do do LGM-30C USAF Wing 1 II III IV V VI Location Malmstrom AFB, Mont Ellsworth AFB, S. Dakota Minot AFB, N. Dakota Whiteman AFB, Mo Warren AFB, Wyo Grand Forks AFB, N. Dakota No of missiles 150 ISO 150 150 200 150 IOC* date 7-63 3-64 8-64 1-65 5-65 12-65 Missile length 53ft 8iin 55ft IO±in 59ft lOin Case materials stage 1 steel steel n.r. stage 2 steel titanium n.r. stage 3 fiass-fibre (lass-fibre (lass-fibre Maximum range (n.m.) 4,500 5,000 6,000+ Re-entry vehicle Avto Mk 5 Avco Mk If GE Mk 12 *IOC, initial operational capability date; n.r., not releasable.
Sign up to
Flight Digital Magazine
Flight Print Magazine
Airline Business Magazine
E-newsletters
RSS
Events
