LGM-30F Minuteman II

Similar to earlier Minuteman I but with increased range and payload. Single warhead, operational since 1965.

 

LGM-30G Minuteman III

Triple MIRV warhead with penaids. First test launch 1968; operational from 1970. Undergoing force modernization programme with Mk 12A warhead and NS-20 guidance system.

PROPULSION: Stage 1, Thiokoi M55E solid-propellant motor, 210,000 lb thrust.Stage II. Aerojet-General SR 19-AJ-1 solid-propellant motor, 60, 300 lb thrust. Stage III, LGM-30F Hercules solid-propellant motor, LGM-30G Thiokoi solid-propellant motor, 34,400 lb thrust.

GUIDANCE SYSTEM: Autonetics inertial

WARHEAD: LGM-30F single thermonuclear warhead in AVCO Mk 11 RV: LGM-30G 3 x thermonuclear warheads, each 175 kilotons in GE Mk 12 or 340 kilotons in GE Mk 12A RV.

LENGTH: 18·2 m

DIAMETER: 185 cm

PERFORMANCE: Speed at burnout, 15,000 mph + ; highest point of trajectory, 700 mi. + ; range LGM-30F 6000 mi., LGM-30G 7000 mi.

Above: An FB-111A approaches Pease AFB, New Hampshire.

 

               

            Work was begun of the scheme in 1966 by Boeing and now, Phase III of the Minuteman Airborne Launch Control System, operational in the mid-1980s, will provide nine EC-135C ALCS aircraft. These will be able to monitor command and make a vote to launch, even if all land-based launch centers are destroyed. The ALCS EC-135s will be in communication with the Airborne National Command Post (ABNCP), an extensively modified Boeing 747 called the E-4B, equipped with satellite communications and facilities to enable the National Command Authorities to monitor an attack. Six E-4Bs will be in service by 1987, able to re-target and launch surviving Minuteman missiles, even if an enemy attack has wiped out fixed ground centres.

 

Strategic bombers

The US Air Force has been in the business of delivering nuclear weapons for almost 40 years, half the lifetime of powered flight. The B-29s that dropped the bombs on Hiroshima and Nagasaki in 1945 were the very first nuclear-weapon delivery systems, followed into service by the piston-engined B-50 nad B-36. The first jets, B-47s, were operational from the early 1950s, but were capable of reaching the Soviet Union only from bases in Europe and North Africa. Crews were briefed to make one-way missions – to crash deep in northern Russia and await some sort of aerial rescue. One veteran of this period told the author. ‘It would have been better to give us Groucho Marx noses and tell us to joke our way out.’

            Then, in Oct. 1952, came the first flight of the XB-52, which, with a range of over 10,000 mi., would spare such embarrassments in the future. It was the prototype for a total of 742-B-52 intercontinental bombers, manufactured in eight major models between 1954 and 1962. The build-up of the complementary KC-135 tanker force began in 1956. By the time of the Cuban missile crisis. SAC’s bombers could have inflicted devastating punishment on the Soviet Union without any kind of comparable response.

            The commitment to the manned bomber, however, began to tail off in the late 1950s, with the advent of guided missiles with intercontinental range. After a long political wrangle these had come not under Army but under Air Force control. The supersonic Convair B-58 Hustler was operational only in small numbers from 1960 to 1969. According to SAC’s commander, General Curtis LeMay, it was too small … ‘it didn’t fit my arse’. The last effort was the huge XB-70 Valkyrie Mach 3 bomber, finally cancelled in 1964. It seemed as if the day of the penetrating bomber was ending fast.

The primary weapon of the existing B-52 fleet before the advent of the air-launched cruise missile was the AGM-69A SRAM (Short-Range Attack Missile), of which some 1140 remain in service with SAC at 16 bases. The B-52G/H can carry up to 20 missiles, 12 on wing pylons.

Above: and eight on an internal rotary launcher.

 

Above: The SRAM is armed with a 300-kiloton W-69 warhead, while some later models have the W-80 warhead of the ALCMs. SRAMs can fly up to 160 km at speeds of Mach 3, with launch at high or low level in a range of preplanned trajectories. The original idea of SRAMs was for the B-52 to blast its way through terminal defences by attacking SAM sites, achieving final penetration to attack primary targets with SRAMs or large free-fall weapons.

 

Above: Boeing KC-135R testbed aircraft for the reengineed tanker fleet.

 

 

            Because of the development of the guided surface to air missile and highly capable air defence radars, bombers could no longer cruise at extreme height and deliver bombs with impunity. The manned, penetrating bomber, equipped with ‘stand-off missiles to achieve final penetration of the target, would hence forth have to fly low and hug the earth to avoid the radar net. This has been very much the story of the last 20 years.

            The B-52 force now numbers some 272, supported by small numbers of training and back-up aircraft. Since entering full USAF service in 1955 the B-52 has undergone numerous improvement programmes and changes of mission. One of the seasons for its longervity is the sheer size of the airframe, able to soak up new equipment and keep flying. From the B-52E model onwards, this massive aircraft, originally designed to cruise serenely in the calm of the stratosphere nine miles high, was modified to operate at low altitude, blasting its way to the target through bad weather, rough terrain and nuclear explosions.       

            The vulnerable airframes, extensively rebuilt as they are, show the effect of hard usage – their skins dimpled and puckered like a collection of old oil cans stitched together to make an aeroplane.

            Two wings of B-52Ds, dating from 1956 and refurbished 20 years later, soldier on as conventional bombers, but will be phased out by the mid-1980s, leaving the G and H models to continue flying until the year 2000. As a ’50-year’ aircraft it would be the equivalent of Sopwith Camels fighting in the Vietnam War.

            There are currently 16 squadrons of Gs and Hs (two training ones), with 151 B-52Gs and 90 B-52Hs, of which 28 are normally assigned to a conventional role. This includes maritime reconnaissance, mine laying and acting as a ‘Strategic Projection Force’ within the Rapid Deployment Joint Task Force (RDJTF). Some 30 B-52 are in active reserve and 223 of all series are in deep storage. Under continuous improvement programmes, the Gs and Hs have received considerable updating of both their offensive and defensive electronic systems, their electro-optical long-range viewing systems (EVS) and satellite communication facilities (AFSATCOM).

            The primary weapon of the B-52 force is the Short Range Attack Missile of AGM-69A SRAM, of which there are estimated to be 1140 still in the SAC arsenal. The SRAM was designed to allow the B-52 force to literally blast its way to target, neutralizing radar and missile sites on the way if necessary. B-52s can carry up to 20 SRAMs externally or on internal rotary launchers. They can fly up to 100 mi. (160 km) following a ballistic trajectory on inertial guidance or using pre-programmed terrain-following manoeuvres, delivering a nuclear punch equivalent to a Minuteman II warhead at the end.

            It was obvious by the mid-1970s that the B-52 force, in spite of its electronic updates and ability to fly low and deliver SRAMs, would eventually be confounded by the ever-tightening net of Soviet strategic missile and interceptor aircraft defence. With the parallel technology of the cruise missile developing, work began on converting a proportion of the venerable bomber force to ALCLM carriers. They would no longer be penetrating bombers, but launch platforms for long-range missiles. Full-scale development started in 1978, funding was sought in the budget for the fiscal year 1983 to adapt 64 B-52Gs and Hs to carry the missile, and in Dec. 1982, the first squadron of 14 aircraft became operational at Griffiss AFB. New York. Full operational capability was planned for 1985 when 104 B-52G aircraft would be loaded, each with 12 ALCMs mounted externally. The conversion of 96 B-52Hs, each to carry up to 20 ALCMs, was to begin in 1986.

 

FB-111A

SAC also currently operates 56 FB-111As, medium-range, high-altitude strategic bomber variants of the F-111 tactical fighter bomber. They can carry up to six SRAMs, six nuclear free-fall bombs or combination of the two but, in theory at least, cannot reach the Soviet Union from US bases at Pease AFB, New Hampshire, and Pittsburgh AFB, New York, without refueling. There have been many proposals to ‘stretch’ the FB-111, none of which has been put into effect. The nuclear-armed F-111 force based in the United Kingdom comes under the command of US Air Forces Europe.

 

Above: The last Polaris A-3 SLBM is offloaded from the submarines Robert E. Lee in Feb. 1982. Ten of the original Polaris boats were decommissioned from 1981, with eight retained as nuclear-powered attack submarines. The US submarine-based deterrent now rests on 19 boats carrying 16 Poseidon C-3 missiles each, and 12 back-fitted with 16 Trident 1 C-4 SLBMs. Meanwhile, the first of the huge purpose-built Trident-carrying Ohio class submarines seen building.

 

 

The Aerial tanker force

The Being 707 airliner which ushered in the age of mass civil jet air travel in the 1960s was based on a military aircraft, the KC-135 flight-refuelling tanker, first flown in 1956. Since then 700 or so KC-135s have been a vital component of US strategic planning and tactical operations worldwide. The ageing KC-135 fleet is being given new engines, initially ex-707 turbofan engines bought on the civil market. It will be subsequently equipped with new CFM56 high-bypass turbofans, keeping its aircraft operational beyond the year 2000.

 

 

Ballistic missile submarines

 

Since is inception in the 1960s, the US Navy’s nuclear-powered ballistic missile submarine (SSBN) fleet has provided the ‘assured destruction’ component of the triad. Sea-launched missiles have a shorter range and are less accurate than their land-based counterparts, suitable for blandly named ‘area’ targets (which means cities) and not for counterforce ‘hard’ targets. Once at sea, however, an SSBN acts as a floating silo, supposedly invulnerable in the reaches of the ocean. Nevertheless, like the airborne and land-based missile forces, the US Navy stands on the brink of a huge modernization programme. Indeed, it was the first off the line with the introduction of the Trident I SLBM (submarine-launched ballistic missile) in 1979.

            The number of US Navy SSBNs reached 41 in 1967, each one originally carrying 16 Polaris missile, but has now dropped to a total of 32. The first of the Ohio class Trident boats, armed with 24 Trident I (C-4) missiles, completed trials in 1981 and the next two of ten in 1983. The first operational Trident patrol was made in a converted Poseidon boat, the USS Francis Scott Key, in Oct. 1979. There are 31 of the equivalent Lafayette class SSBNS in service, 12 now retrofitted with Trident Is to make a total of 192 missiles. The total number of missiles is therefore 568 SLBMs delivering 5152 MIRV warheads, a sea-based deliverable load of 333 megatons.

 

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