us missile systems

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Chapter 17

U.S. MISSILE SYSTEMS

On 27 October 1955, a contract wasawarded to produce another ICBM, theTitan I. The Thor and Jupiter IntermediateRange Ballistic Missile (IRBM) programsalso began in December of 1955, with thehighest possible priority. The Army hadresponsibility for all short-range (under200 miles) surface-to-surface missiles.The Navy had control of all ship-basedmissiles and the Air Force got all othersurface-to-surface missiles.

This chapter covers land-basedIntercontinental Ballistic Missiles(ICBMs), submarine-launched ballisticmissiles (SLBMs), and (briefly) cruisemissiles.

Brief History of the ICBM

Origins

The first reference to use of rocketsdates from 1232 when the Chinese

defenders of K'aifung-fu used firearrows against attacking Mongols.Progress in rocketry was slow, at best, forthe next seven centuries.

Fig. 17-1. Thor and Atlas I Missiles

The Germans began development of amissile arsenal during the 1930s atKummersdorf and Peenemnde, withincreased emphasis during World War II.These experiments resulted in theVergeltsungswaffe Ein and Zwei,(Revenge weapons one and two), or V-1and V-2. The V-2 was 46 feet long andused alcohol and liquid oxygen aspropellants. It reached an altitude of 50to 60 miles, had a maximum range of 200miles and carried a one ton warhead. Thesystem's accuracy was two and one-halfmiles. The war ended before the resultsof research into longer-range(transatlantic) two-stage rockets calledthe A-9 and A-10 could be used. Theseweapons might have been operational by1948.

The United States and the SovietUnion recruited as many German

scientists as possible following the war.Each began their own research programsinto the use of missiles as weapons.Funding and weight limitations preventedthese programs from quickly advancing.It wasn't until 1954 that Air ForceSecretary Talbott directed all necessarysteps be taken to advance the AtlasICBM project.

The first U.S. IRBM was the Thor(Fig. 17-1). It was deployed in theUnited Kingdom between 1959 and 1963.The Thor was housed horizontally in anabove-ground shelter. It had to be raised

AU Space Primer 7/23/2003

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to the vertical position and fueled beforelaunch. Its propellants were RP-1 (a highgrade kerosene) and liquid oxygen. TheThor had a range of 1,500 nautical miles(NM) and could place a one megatonwarhead within 4,600 feet of the target.

First Generation ICBMs

The first Atlas D ICBM was launched9 September 1959 at Vandenberg AFB,California. General Thomas D. Power,CINCSAC, then declared the Atlasoperational. Only six days later, aMinuteman R & D tethered launchoccurred at Edwards AFB, California.This was a model with inert second andthird stages and a partially charged firststage. It had a 2,000 foot nylon tether to

keep the missile from going too far. On31 October 59, the first nuclear-tippedAtlas was on alert at Vandenberg AFB.Deployment of the Atlas continued inthree versions, the D, E and F models.The D model was housed horizontally inan above-ground, soft building anderected for launch (plus three D modelswere in soft, vertical gantries atVandenberg AFB). It used acombination of both radio and inertialguidance.

The E model incorporated manyimprovements over the D model.Perhaps the most significant was thereplacement of radio guidance with anall-inertial system, making the E modelinvulnerable to jamming. The E modelwas also housed horizontally, but it wasin a semi-hard coffin launcher that wasburied to reduce its vulnerability to blastand overpressure.

The F model was kept in anunderground, hardened silo and raised tothe surface by an elevator for launch; this

was called hard silo-lift. The silo wasnearly 180 feet deep.The Titan I was also being developed

and deployed in a similar configurationas the Atlas F. Both used the samepropellants and the same silo lifttechnique. One primary difference wasin the command and control. The Atlas Fsystem had one launch control center

connected with, and in command of, onesilo and missile. The Titan I system hadthree silos connected to the undergroundlaunch control center. Another differencewas that the Titan I used a radio-inertialguidance system similar to the Atlas D.

The sixth and last Titan I squadronbecame operational at Mountain HomeAFB, Idaho on 16 August 1962. Onlyfour months later, on 20 December, thelast Atlas F squadron at Plattsburgh AFB,New York achieved operational status.

Even as these milestones werereached, the days of the first generationICBMs were numbered. The newer TitanII and Minuteman ICBMs were more sur-vivable and quicker reacting, along withbeing more economical to operate andmore reliable. On 24 May 1963, General

Curtis E. LeMay, Air Force Chief ofStaff, announced the phaseout of the At-las D and E and the Titan I. By its com-pletion, that phaseout also encompassed theAtlas F, with the last Atlas F beingremoved from alert at Lincoln AFB, Ne-braska on 12 April 1965 and shipped toNorton AFB, California for storage.

Second Generation ICBMs

The second generation of ICBMs, theTitan II and the Minuteman, shared onlyone characteristic--they were housed andlaunched from hardened undergroundsilos. The Titan II was a large, two-stageliquid-fueled missile that carried a singlewarhead. Its range was about 5,500 NM.The missiles were deployed at threewings. Davis-Monthan AFB, Arizonawas the home of the first operationalwing. McConnell AFB, KS and LittleRock AFB, AR were the other two.


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The Titan II offered five distinct ad-vantages over the Titan I. First, its reac-

tion time was reduced from 15 minutes toless than one minute because it used stor-able hypergolic propellants. Second, itused an all-inertial guidance system, amajor improvement over its radio-controlled predecessor. Third, the mis-sile carried the largest and most powerfulwarhead ever placed on a U.S. missile.Fourth, each launch complex contained


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only one missile, instead of the cluster ofthree used in Titan I; this separation en-hanced survivability. And last, the TitanII was designed to be launched from be-low ground inside its silo, also to limit itsvulnerability to damage, except during

the earliest stages of flight.The Minuteman is a three-stage, solid-fueled missile housed in a remote launchfacility. Its range is also in excess of5,500 NM. From the beginning, it wasintended to be a simple, efficient and sur-vivable weapon system. Its main featuresare reliability and quick reaction.

The first Minuteman, the Minuteman IA, went on strategic alert during theCuban missile crisis of October 1962.President Kennedy later referred to thismissile as his ace in the hole during

negotiations with the Soviets.The Minuteman II became operational

in 1964 and replaced many of the Min-uteman Is. This system, known as theLGM30F, or more simply the F model,was over 57 feet long, weighed over73,000 pounds and carried one warhead,like the Minuteman I.

The Titan crew consisted of two officers

and two enlisted technicians, where theMinuteman crew is composed of only two

officers. Control of a single Titan missilewas done from the Launch Control Center(LCC). Minuteman uses a similar proce-dure, but the crew controls 10 to 50 mis-siles.

Because the Titan was increasingly

expensive to operate and hampered by aseries of accidents, the Reagan Admini-stration announced its deactivation in Oc-tober 1982. The system deactivationbegan in 1984, and the last Titan II wingwas deactivated in August 1987. TheBush Administration began deactivationof the Minuteman II to comply with Stra-tegic Arms Reduction Treaty (START)requirements. The last Minuteman II wasremoved in 1998.

Third Generation ICBMs

While Titan II missiles were deployedin only one model, the Minuteman seriesspanned several models. The latest, andonly operational version, is the Minute-man III G. The last Minuteman III wasdeployed in July 1975, so this is the old-est ICBM on alert. It is almost 60 feettall and weighs approximately 79,000

pounds. The Minuteman III originallycarried three reentry vehicles, each capa-

Fig. 17-2. Typical ICBM Flight Profile


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ble of maneuvering to strike a differenttarget. Upon START II entry into force,the Minuteman force will be downloadedto a single reentry vehicle.

The Minuteman is hot-launched (igni-tion occurs in the silo) and flies out

through its own flame and exhaust. Anavcoat material protects the first stagefrom the extreme heat generated duringthis process. Once ignition occurs, themissile will pass through several phasesof flight, beginning with the boost phase.A typical flight profile is shown in Fig-ure 17-2.

The newest U.S. ICBM is thePeacekeeper. It is a four-stage, solid-fuelmissile which replaced 50 Minuteman IIImissiles at F.E. Warren AFB, Wyoming.These missiles are deployed in converted

Minuteman silos. The first ten Peacekeepermissiles achieved operational alert status inDecember 1986 as part of the 400thStrategic Missile Squadron. WhenSTART II enters into force, Peacekeeperwill be deactivated.

The Peacekeeper is 71 feet long andweighs 195,000 pounds--nearly threetimes the weight of a Minuteman III.This allows it to carry up to 12 reentryvehicles, although 10 is the operationalconfiguration. The missile is about sevenand one-half feet in diameter on all of itsstages.

All four stages are protected duringlaunch and in its flight environment by anethylene-acrylic rubber coating. No abla-tive material is needed because it uses acold-launch technique similar to the sys-tem used by the Submarine LaunchedBallistic Missile (SLBM) submarines.The Peacekeeper is protected inside thecanister by Teflon-coated urethane pads.Nine rows of pads are used to protect andguide the missile smoothly up and out of

the canister. The pads fall away whenexiting the canister.The cold launch system uses a rein-

forced steel canister to house the missile.At the bottom of the canister is a LaunchEjection Gas Generator (LEGG). Asmall rocket motor is fired into 130 gal-lons of water contained in the LEGG res-ervoir. This creates steam pressure that

pushes the Peacekeeper up and out of thecanister prior to first stage ignition.

The presently deployed ICBM forceconsists of Minuteman III G andPeacekeeper missiles. They are deployedas follows:

200 Minuteman III, Malmstrom AFB,Montana150 Minuteman III, Minot AFB,North Dakota, and150 Minuteman III and 50 Peace-keeper, F.E. Warren AFB, Wyoming.

ICBM Characteristics

Mission Profile and Equipment

The ballistic missile as a weapon is of-

ten compared to an artillery cannon andits ballistic projectile. Important to theaccuracy of the artillery projectile are itselevation and speed. Apart from atmos-pheric resistance, gravity is the only vitalforce operating on the projectile, causinga constant acceleration fall to earth. Asthe distance to the target increases, somust the elevation (angle of launch to-ward the target) or speed (muzzle veloc-ity) of the projectile increase.

In order for the ballistic missile reen-try vehicle (RV) to reach the target, themissile must be aimed toward the desiredimpact point and given a specific speedand altitude. There is one point some-where along the missile flight path atwhich a definite speed must be achieved.The flight control system is responsiblefor getting the missile to this point.


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From the moment of lift-off, the mis-sile must stabilize in its vertical climb. Itmust be rolled about its longitudinal axisto the target azimuth and pitched overtoward the target. The missile must be

accelerated, staged and given any neces-sary corrections along its roll, pitch andyaw axes, and various engines must beignited and terminated at precise times.In addition, the reentry vehicle must bearmed and separated from the missile.These operations are performed by theflight control system through two basicsubsystems; (1) the autopilot subsystem


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(or attitude control) and (2), the inertialguidance subsystem or radio.

An inertial guidance system iscompletely independent of groundcontrol. It is capable of measuring itsposition in space, computing a trajectory

taking the payload to the target. Itgenerates (1) steering signals to properlyorient the missile, (2) engine cutoffsignals, and (3) the warhead prearmingsignals.

Reentry Vehicle Design

A ballistic missile is only poweredfor a short time during flight. The totalflight time for an ICBM is about 30minutes, but powered flight lasts only

five to 10 minutes. The remainder of thetime is spent coasting to the target.The velocity of powered flight may reach15,000 mph, but it really is gravity thatdoes the work of getting the payload tothe target. Once the vehicle begins toencounter atmospheric drag duringreentry, aerodynamic heating and brakingbegins. Induced drag and lift affect thereentry vehicles trajectory. There are nocontrol surfaces on a true ballistic reentryvehicle. It acts more like a bullet as itfalls to the target.

Reentry vehicles have two types ofheat shielding: heat sink and ablative.Heat sink vehicles disperse heat througha large volume of metal, while ablativevehicles have coverings that melt or burnoff. Essentially, the covering absorbs theheat and sloughs off, carrying away theheat. Continued use of heat sink vehiclesbecame impractical because of the trade-off between RV weight, booster size andrange. The use of ablative vehiclesreduced these problems.

Reentry is incredibly severe, with an

interesting tradeoff between survivabilityand accuracy. In general, the steeper thereentry angle, the more accurate theballistic vehicle. However, the steeperthe angle, the higher the temperature andG-loading encountered. The problem isto design a reentry vehicle that will notvaporize when reentering the earth's

atmosphere and yet maintain the neededaccuracy. An intense program coveringshock tests, materials research, hypersonicwind tunnel tests, ballistic research, nosecone drop tests and hypersonic flight wasused during development.

There are several design requirementsfor an RV. Foremost is the ability tosurvive the heat encountered duringreentry. A body reentering the atmosphereat speeds approaching Mach 20experiences temperatures in excess of15,000 degrees Fahrenheit. In practice,the RV never reaches this temperaturebecause of a strong shock wave ahead ofthe blunt body that dissipates more than90 percent of this energy to theatmosphere. In addition, the internaltemperature must be kept low enough to

allow the warhead to survive reentry. Asthe RV reenters the atmosphere, itencounters tremendous decelerationforces--as high as 50 Gs. All internaloperational components must functionunder these extreme conditions andadditionally, must withstand the highlateral loads and intense vibrations alsoencountered.

An RV may be deflected from itscalculated trajectory by aerodynamic liftforces. Stability, assisted by a form ofattitude control and further augmented bysome means of averaging deflection,must be designed into the RV. Anarming and fusing mechanism must beincorporated into the RV to prevent non-programmed weapon detonation. It alsomust have a sensing mechanism toindicate the proximity of the target andarm the warhead. The weight of thevehicle must be kept to a minimum tomaximize range. The higher the terminalvelocity, the less likely the RV will beintercepted. Higher velocity also

decreases the probability of missing thetarget due to atmospheric deflection.

Nuclear Weapons Effects

Nuclear weapons effects are normallydivided into three areas: initial, residualand long-lived. Residual effects are


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those which begin about one minute afterthe detonation and continue for about twoweeks. These would include fallout andassociated radiation. Long-lived effectswould include the subsequent damage tothe environment and some radiation

concerns. It is generally the initialeffects that are most germane to militarymatters. There are six primary nuclearweapon effects:

Electromagnetic Pulse (EMP) Nuclear radiation Air blast Ground shock Thermal radiation Dust and debris.

Each of these effects can be compared

to our normal phenomena. Electro-magnetic pulse is similar to a lightningbolt, producing a tremendous surge ofelectrical current and generating hugemagnetic fields both of which affectelectrical equipment. Depending on thealtitude of the explosion, it can haveeffects thousands of miles from thedetonation. Nuclear radiation is similarto a powerful X-ray and varies dependingon the burst option used (Fig. 17-3).

Air blast is the wind generated by thedetonation. These winds are ten timesstronger than those found in the mostpowerful hurricane. They actually slapthe earth hard enough to contribute to theground shock at the detonation site. The

ground shock is nearly 250 times worsethan the greatest earthquake. The lateralaccelerations are transmitted over largedistances at very high speeds. Heat isanother product, with the sun's thermalradiation a useful comparison. The

temperatures in the fireball reach upwardsof 14,000 degrees Fahrenheit. As acomparison, the sun's surface temperatureis approximately 11,000 degrees.

Finally, a ground burst will generatelarge amounts of dust and debris. Thedebris can bury undamaged structureswhile the dust clouds can act assandblasting equipment on aircraft andmissiles flying through them.

The most familiar phenomena relatingto both blast effects and target hardness isoverpressure. This is measured in

pounds per square inch (psi). A onecubic foot block of concrete exerts onepsi on the ground beneath.

Stacking a second block on the firstwill increase the pressure to two psi, etc.Five Washington Monuments placed atopeach other equates to 500 psi; a sonicboom registers a mere 0.3 psi.

Blast overpressure is heightened bythe interaction of the primary shock waveand a reflected shock wave. The primary

wave is radiatedoutward from groundzero and compresses theair in front of it. Thiswave will strike theearth and reflect upwardand outward, creating thereflected wave. Thisreflected wave movesfaster than the primarywave because the airresistance has beendecreased by the passageof the first wave. The

primary wave will bereinforced by the reflectedwave, forming a mach

front. A drawing of this phenomenonwould resemble the letter Y with theintersection of the Y termed the TriplePoint. Below the triple point, the twoblast waves will strike like a single,

Fig. 17-3. Nuclear Weapon Effects versus Distance


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powerful blow. Anything above thetriple point is the overpressure.

Table 17-1 shows the effects ofoverpressures on building materials.

The power of a nuclear explosion isalmost incomprehensible, but the

following example may help to put it intoperspective. Five million one-ton pickuptrucks loaded with TNT would have thesame explosive yield as a single fivemegaton nuclear weapon. A surfaceburst of this weapon will yield the

following results at a distance 3,200 feet(0.6 miles) from ground zero:

Fireball diameter: 2.8 miles 5.5 billion kW hours X-rays 14,000 degrees 250 G lateral acceleration

500 psi 3,500 mph winds 20 inches of debris Debris weighing as much as 2,000

lbs. impacting at 250 mph Crater: 3,000 ft wide; 700 ft deep

Table 17-1. Overpressure Sensitivities

Structural Element Failure Approximate Side-on Peak

Overpressure (PSI)

Glass windows, large & small Shattering, occasional frame failure 0.5 - 1.0

Corrugated asbestos siding Shattering 1.0 - 2.0Corrugated steel paneling Connection failure followed by

buckling

1.0 - 2.0

Wood-frame construction Failure occurs at main connections,

allowing a whole panel to be blown in 1.0 - 2.0

Concrete or cinder block wall

panels, 8-12 inches thick

(unreinforced)

Shattering

1.5 - 5.5

Brick wall panel, 8-12 inches thick

(unreinforced)

Shearing and flexure 3.0 - 10.0

The effects on people are shown in Table 17-2 (next page). Note: rem stands for

Roentgen Equivalent in Man; its a standard measurement of radiation effects on humans.A rem is the equivalent of one roentgen of high-penetration x-rays.


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Table 17-2. Nuclear Radiation Effects on People

Dose in Rems

(see note

above)

Radius in feet from 20 KT

Air Burst

Probable Effects

Unprotected

Persons

Troops in

Covered

Foxholes0 - 80 5,550 4,200 No obvious effects. Minor blood changes possible.

80 - 120 5,250 3,900 Vomiting and nausea for about one day in 5-10% of

exposed persons. Fatigue, but no serious disability.

130 - 170 4,800 3,750 Vomiting and nausea for about one day followed by some

symptoms of radiation sickness in about 25% of exposed

persons. No deaths anticipated.

180 - 260 4,500 3,600 Vomiting and nausea for about one day followed by some

symptoms of radiation sickness in about 50% of exposed

persons. No deaths anticipated.

270 - 390 4,200 3,300 Vomiting and nausea in nearly all persons on first day,

followed by other symptoms of radiation sickness. About

20% deaths within two to six weeks after exposure.

Survivors convalescent for up to three months.

400 - 550 3,900 3,000 The mid-lethal dose. Vomiting, nausea, and radiation

sickness symptoms. About 50% deaths within one month.

Survivors convalescent for up to eight months.

550 - 750 3,750 2,850 Vomiting and nausea in all persons within a few hours,

followed by other symptoms of radiation sickness. 90% to

100% deaths. The few survivors convalescent for six

months.

1,000 3,600 2,550 Vomiting and nausea in all persons exposed. Probably no

survivors.

5,000 3,000 2,250 Incapacitation almost immediately. All persons will die

within one week.

Current ICBMs

Fig. 17-4. Minuteman Launch Facility (LF)

Minuteman III (LGM-30G)

The Minuteman G model is a three-stage, solid-propellant, inertially guided,Intercontinental Ballistic Missile with arange of more than 6,300 miles. Itemploys a Multiple IndependentlyTargetable Reentry Vehicle (MIRV)system with a maximum of three reentryvehicles. The Post Boost Control System(PBCS) provides maneuvering capabilityfor deployment of the reentry vehiclesand penetration aids. It is comprised of aMissile Guidance Set (MGS) and aPropulsion System Rocket Engine(PSRE). The G model is maintainedon alert in a hardened, underground,unmanned Launch Facility (LF) as


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depicted in Figure 17-4, the same as theF model was. The LFs are at leastthree miles apart and three miles from theLCC. Each LF in the squadron isconnected to other squadron resources bya buried cable system. This allows one

LCC to monitor, command and launch itsown ten missiles (called a flight) and allfifty missiles in the squadron whennecessary.

Enhancements and modifications arein progress to maintain the viability ofthe force at least until the year 2020. Onthe missile itself, the first and second-stage motors are being washed out andrepoured. The third stage motors are beingremanufactured. A major effort is underway to test an environmentally acceptablepropellant replacement. The Rapid

Execution and Combat Targeting(REACT) Service Life ExtensionProgram (SLEP) is designed to providelong-term supportability of the agingelectronics components. It also modifiesthe launch control center allowing real-time status information on the weapons andcommunications nets to correct operabilityproblems, improve responsiveness tolaunch directives,and provide rapidretargetingcapability.

Propulsion System.Three solid propel-lant rocket motorsmake up the pro-pulsion system ofthe Minuteman Gmodel (Fig. 17-5).The first stage usesa Thiokol M-55solid propellantmotor that gen-

erates 200,400pounds of thrust.The second stagemotor is built byAerojet (SR19-AJ-1), developing60,700 pounds ofthrust. These stagesare identical to the

Minuteman F model. The third stage islarger than the F model and it uses asingle, fixed exhaust nozzle with theLiquid Injection Thrust Vector Control(LITVC) system and roll control ports forattitude control. The third stage is a

Thiokol SR73-AJ-1 motor that delivers34,500 pounds of thrust (the third stageon the Minuteman II also uses this motor,but it only generates 17,100 pounds ofthrust). Thrust termination is similar to theF model but there are six thrusttermination ports mounted at the forwardend of the third stage. Theseblow out when the desired point inspace is reached to employ all weapons.The actual deployment of the reentryvehicles and penetration aids isaccomplished by a mini fourth stage,

the PBCS. It fires a liquid-fueled engineperiodically to maneuver throughout thedeployment sequence. This processallows the G model to hit up to threeseparate targets at different ranges withgreat accuracy.

Airframe. The missile consists of rocketmotors, interstages, a raceway assemblyand the Mark 12 or 12A reentry system.The reentry system includes a payloadmounting platform, penetration aids,reentry vehicles and an aerodynamicshroud. A shroud protects the reentryvehicles during the early phases ofpowered flight. All three stages of theG model are delivered preloaded fromthe manufacturers and emplaced into theLF as one unit. The PBCS and thereentry system are assembled on themissile in the launch tube after missileemplacement.


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Fig. 17-5. Minuteman


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Peacekeeper (LGM-118A)

The Peacekeeper is a four-stage,inertially guided ICBM, with a rangeof more than 6,000 miles. The firstthree stages are solid propellant with

Kevlar 49 casings. The fourth stageis liquid propelled. The Peacekeepercan carry eleven Mark 21 or twelveMark 12A reentry vehicles. Theoperational deployment is ten Mark21s. The guidance and controlsystem is in stage four and uses araceway with fiberoptic cabling totransmit commands to the first threestages. Peacekeeper missiles aremaintained on alert in modifiedMinuteman LFs (Fig. 17-6) andcommanded by modified Minuteman

LCCs. Only one squadron of Peacekeepermissiles is operational and it is deployedat F.E. Warren AFB, Wyoming.

Fig. 17-6. Peacekeeper Launch Facility

Airframe. The missile consists of rocket

motors, interstages, a raceway assembly,and the reentry system. The reentrysystem is the Post Boost Vehicle minusthe fourth stage. Peacekeeper isassembled in its canister at the LFfollowing delivery of the componentsfrom the manufacturer. Along withseveral special vehicles, an air elevatoris used in this assembly process to lowerthe missile one stage at a time into thecanister. This isn't an easy task. It's beendescribed as similar to stacking BBs.

Propulsion System. Unlike theMinuteman, Peacekeeper's engines do notignite in the silo. The missile is in acanister with a Launch Ejection GasGenerator (LEGG). Like a sea-launchedballistic missile, the Peacekeeper isejected from the canister and propelledsome 80 feet into the air before the firststage engine ignites. Peacekeeper's firstthree stages are solid propellant withsingle exhaust nozzles. The first stagenozzle is movable through hydraulicactuators powered by a hot gas generatorand turbine centrifugal pump. A similargas generator turbine assembly extendsthe nozzles on stages two and three.These Extendable Nozzle Exit Cones(ENEC) are folded before stage ignitionand extend to provide better performancecharacteristics without increasing stagediameter or length. The fourth stage,

deployment module, guidance andcontrol section and shroud make up thePost Boost Vehicle (PBV). The systemoperates like the PBCS on theMinuteman G model using the newAdvanced Inertial Reference Sphere(AIRS) and the Missile Electronics andComputer Assembly (MECA).

U.S. SLBMs

SLBM History

In 1955, the National Security Councilrequested an IRBM for the defense of theU.S. They further decided that part of theIRBM force should be sea-based. As aresult, the Navy was directed to design asea-based support system for the existingliquid-fueled Jupiter IRBM. This led tothe development of the Special Projects

Office (SPO) by the Secretary of theNavy. The SPO was tasked withadapting the Jupiter IRBM for shipboardlaunch. Originally, the Jupiter was anArmy missile designed for land-basedlaunches. Because of the unique handlingand storage requirements of liquidpropellants, Navy crews encountered


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storage and safety problems. As a result,the Navy began a parallel effort to the AirForce in the development of alternatesolid-fueled rocket motors.

Polaris. The Polaris (A1) program beganin 1957; later versions were called A2and A3. Its innovations included a two-stage solid propulsion system, an inertialnavigation guidance system, and aminiaturized nuclear warhead.

Production ended in 1968 after more than1,400 missiles had been built. The lastversion, the A3, had an increased range(2,900 miles compared with 1,700 milesfor the A2 model) and multiple warheadcapability. The missile was replaced bythe Poseidon SLBM and later by theTrident.

Breakthroughs in solid fuels, whichresulted in smaller and more powerful

motors, occurred in 1956. Reductions inthe size of missile guidance, reentryvehicles and warheads further aided insmaller missile technology. The firstsolid-fueled missile incorporating thisnew technology was named Polaris. Thefirst submarine launch of a Polarisoccurred in July 1960 from the USSGEORGE WASHINGTON. Three hourslater a second missile was successfullylaunched. These two shots marked thebeginning of sea-based nucleardeterrence for the U.S.

Poseidon. The Poseidon (C3) weaponsystem was deployed on Poseidon(Lafayette-class) submarines. ThePoseidon submarine was similar to the

one that carried the Polaris. They carried16 missiles. Poseidon submarines, nowout of service (except for two convertedto SSNs) were deployed from Charleston,South Carolina and Holy Loch, Scotland.

Since then, the Fleet Ballistic Missile(FBM) has progressed through Polarisand Poseidon, to the Trident I and TridentII missiles of today. The Poseidon addedMIRV capability while both generationsof Trident increased range and accuracy.

There are other changes as well. Thelauncher system evolved from compressedair units to steam-gas generators. Themissile guidance systems now use in-flight stellar updates. Navigation hasmatured from external fixes to on-boardcomputers. The missile fire control systemhas developed through semiconductor andsolid-state electronics to the presentmicrochip technology.

Trident I. The Trident I (C4) backfitweapon system was initially deployed onPoseidon submarines starting in 1979. TheTrident I system consisted of the TridentI missile and updated launch andpreparation equipment. The Trident Imissile has increased range and accuracyover the Poseidon (C3). The updatedweapon system included manyimprovements resulting from newtechnology.The first SSBN was constructed by

cutting a fast-attack submarine (USSSCORPION) into two pieces andinserting a 16 tube missile compartmentsection. Since then, several classes ofsubmarines have been designed and builtspecifically for the FBM mission. TheOhio (726)-class submarine is the newestgeneration of SSBN. The first submarine

of this class was deployed in 1981. Thisis the same class of submarines that carrythe Trident II strategic weapon system(SWS) and missile. Currently, the UnitedStates has two different strategic weaponsystems (Trident I and Trident II).

The Trident I was deployed on earlyOhio-class submarines in 1981; the pre-Ohio class submarines were retired in1995. This weapon system consists ofthe Trident I missile and new/modifiedlaunch and preparation equipment. Themodifications to the launch and preparationequipment result largely from

improvements in electronics technology.The Ohio-class submarine was designedfrom the ground up to carry the newweapon system. It is larger, faster andquieter than the Poseidon submarine andcarries 24 Trident I missiles.


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Trident II. The Trident II (D5) wasdeployed on the later Trident (Ohio-class) submarines, starting in March 1990.This weapon system consists of Trident IImissiles and a combination of new andmodified preparation and launch

equipment. The Trident II missile issignificantly larger than the Trident Ibecause of the increased size of the firststage motor, giving it a greater payloadcapability. The Trident II uses the latestelectronics for improved reliability andmaintainability. The launch platform isbasically the same submarine that carriesthe Trident I. They are deployed fromNaval Submarine Bases at Bangor, WAand Kings Bay, GA.

The Trident II is also provided to theUnited Kingdom (U.K.) which puts its

own warheads on the missiles. The U.K.deploys them on Vanguard-classsubmarines.

Current SLBMs

Trident I C-4

The Trident I C-4 is a three-stage,solid propellant, inertial/stellar-guided,ICBM. It has a range of 4,000 nauticalmiles (4,600 statute miles). It carries a

MIRVed system and was originallydeployed on the Lafayette-class (all retired) andcurrently on the Ohio-class(Trident) submarines.

Propulsion Subsystem.Three solid propellantrocket motors make up thepropulsion system of the C-4 missile (see Fig. 17-7).Each stage of the missilecontains a nitroglycerin and

nitrocellulose-base propellantencased in a Kevlar/epoxyrocket motor casing. Stage Iis 14.75 feet long or abouthalf the missile's length. Itis six feet wide and weighsapproximately 19,300 pounds.The third stage is ten feet

tall, 2.6 feet wide, and weighs 4,200pounds. Each stage is controlled by asingle movable nozzle activated by a gasgenerator. The PBCS and RV mountingplatform surrounds the third stage rocketmotor. At a predetermined time, a small

rocket located on the top of the thirdstage fires, backing it away from thePBCS. Now taking on a doughnutappearance, the PBCS fires and proceedsto the RV deployment points.

Airframe. The airframe of the C-4 issimilar to the Poseidon C-3. The C-4 hasa length of 34 feet, a diameter of aboutsix feet, and weighs about 73,000pounds. An aerodynamic spike(AEROSPIKE) actuates by an inertialpyrotechnic device during first stage

flight. This aerospike increases missilerange by reducing aerodynamic drag byabout 50 percent. The nose fairing on theC-4 is also constructed of Sitka Spruce.The fairing jettisons during second stageburn.

Trident II D-5

The Trident II D-5 is a three-stage,solid propellant, inertial/stellar guided,ICBM. It has a range of over 4,000nautical miles (over 4,600 statute miles).It carries a MIRVed re-entry system andis deployed on Ohio-class submarines.

3

2

1

Fig. 17-7.

Trident I

Propulsion Subsystem. Three solid

propellant rocket motors make up the

propulsion subsystem of the Trident II D-

5 missile (Fig. 17-8). Each stage of the

D-5, like the C-4, contains nitroglycerin

and nitrocellulose-based propellants in the

motor casing. The motor casing for the

first and second stages is constructed of

graphite and epoxy, while the third stageof the D-5 consists of Kevlar/epoxy

materials; these materials are lighter than

those used in the Trident I. Stage one is

approximately 26 feet long, almost seven

feet wide, and weighs 65,000 pounds.

Stage two is eight feet long, seven feet


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wide and weighsapproximately 19,000lbs. The third stage is 10feet tall, 2.5 feet indiameter, and weighs4,200 pounds. A single

movable nozzle, actuatedby a gas generator,controls each stage. Likethe C-4, the third stage ofthe D-5 is surrounded bythe PBCS and the RVmounting platform.During third stageseparation, the stage slidesback through theequipment section alongsupport rails. Taking ona doughnut appearance,

the PBCS fires andproceeds to thedeployment points forRV release.

Airframe. The Trident II D-5 is 44 feetin length, approximately seven feet indiameter and weighs 130,000 pounds.Like the Trident I C-4, the D-5 employsan AEROSPIKE during first stage burn.The nose fairing is constructed of SitkaSpruce and jettisons during second stageburn. All other airframe characteristicsof the D-5 are the same as the PoseidonC-3 and the Trident I C-4.

Ohio Class Submarine

All 18 Ohio-class submarines wereoperational as of 1998. Shown in Fig.17-9, each is 560 feet long, 42 feet in

beam and has a submerged displacementof 18,700 tons. Although over two timeslarger than the Franklin-class in volumedisplacement, the Ohio-class requiresonly 16 officers and 148 enlisted crewmembers. The Ohio-class submarine

carries up to 24 Trident I or Trident IImissiles.

Fig. 17-8.

Trident II

1

2

3

Cruise Missile Weapon Systems

Cruise missiles are described here forcomparison with the previous weaponsystems. There are several majordifferences between ballistic missiles andcruise missiles. First is that ballisticmissiles are only in powered flight for ashort time (being fired hundreds of milesup, then letting gravity carry them to a

target). Cruise missiles are continuouslypowered because they fly close to theearth. The second major difference is aconsequence of the first; cruise missileshave a much shorter range. Third, cruisemissiles fly at subsonic speeds whileballistic missile warheads arrive at up toMach 20; so cruise missiles have a lot incommon with unmanned aircraft.

Cruise missile weapon systems consistof the Air Launched Cruise Missile(ALCM), the Sea Launched CruiseMissile (SLCM) and the AdvancedCruise Missile (ACM). While the launchtechniques used by each system aredifferent, their airframe characteristics,guidance systems, propulsion systemsand flight profiles are similar.

Airframe

Cruise missile airframes (Fig. 17-10)are approximately 20 feet long and 20inches in diameter. These missiles weighclose to 3,000 pounds at launch. The

guidance system in the forward portion ofthe missile uses two separate techniquesto achieve outstanding accuracy. ATerrain Contour Matching (TERCOM)system provides periodic location updatescorrecting any drift or errors in theinertial guidance set. Later missilesinclude GPS guidance. Aft of the

Fig. 17-9. Ohio-class Ballistic Missile Submarine


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guidance compartment is the warhead.The ALCM and ACM carry nuclearwarheads, while the SLCM may be eithernuclear or conventional. Behind thewarhead is the fuel tank for the turbofanengine. After the fuel tank is the

midsection where the missile's wingsmeet the fuselage.

SLCM and ACM wings are eight feetseven inches long and extend straight outfrom the fuselage. ALCM wings are 12feet long and swept back 25 degrees. Aftof the midsection is the air inlet for theturbofan engine. SLCM and ACM airinlets are on the bottom of the airframewhile the ALCM's is on top. SLCM andALCM air inlets are kept retracted intothe airframe until needed during flight.Immediately behind the air inlet is the tail

cone section which contains an F-1017-WR turbofan engine. This engine weighs145 pounds and produces about 600pounds of thrust. The tail cone sectionalso provides attachment points for themissile's tail fins. Finally, there is a solidrocket motor on the SLCM. This rocketaccelerates the missile to a speed of 550mph

Tomahawk Land Attack Missile (TLAM)

The Tomahawk is a long-range cruise

missile that can be used against surfaceships or land targets, employing severaldifferent types of warheads. The missileentered service in submarines in 1983,and is also launched from surface vessels.TLAMs are launched from standard 21-inch torpedo tubes and, in the later LosAngeles-class submarines, from 12

vertical launch tubes (in addition to thestandard 4 horizontal tubes).

The Tomahawk is an all-weather,subsonic missile which, when launchedfrom a submarine, rises to the surface anddeploys small wings and starts a small

turbofan engine which propels it towardthe target. The small size of theTomahawk gives it a low radarcross section and its low-levelflight profile makes it difficultto intercept. The TLAM islaunched on a preset courseabove the water and, as itcrosses over land, switches toan inertial and Terrain ContourMatching (TERCOM) systemto guide the missile to its targetwith an accuracy measured in

feet.Fig. 17-10. Sea Launched Cruise Missile (SLCM)

TLAM warheads consist ofconventional high explosives (TLAM-C)or scattering bomblets (TLAM-D).Block III TLAMs have an extended rangeand incorporate a Global PositioningSystem (GPS) receiver for improvedreliability and time-of-arrival control topermit coordinated strikes between othermissiles and aircraft. The GPS featurewill also make it easier to retarget themissiles while at sea, thus enhancingmission planning.

ALCM Airframe

The ALCM's overall dimensions andcomponent locations are similar to theSLCM. The ALCM (Fig. 17-11) differsfrom the other cruise missile variants inthe shape of its airframe and wings, thelocation of its air inlet and its lack of asolid rocket motor.


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Fig. 17-11. ALCM


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Launch Flight Profile

The SLCM comes in a canister, whichfunctions as a shipping and storagecontainer and firing tube. A canisterloaded with a warhead-equipped missile

is an All-Up-Round (AUR). When alaunch command is received, the SLCM'ssolid rocket motor fires and acceleratesthe missile to a speed of 550 mph. Thetail fins deploy six seconds after thebooster ignites. Two seconds later theturbofan sustainer engine starts andpropels the missile to its Initial TimingControl Point (ITCP). Since ALCM'sinitial velocity is provided by its carrieraircraft, it does not need a rocket booster.The ALCM's wings, elevons and findeploy immediately after the missile is

released from the aircraft. The turbofanengine then starts and the flight controlsystem begins. The ALCM thenproceeds to the ITCP.

Flight profiles from the ITCP to thetarget are similar for both cruise missiles.A pre-programmed path stored in itsonboard computer (inertial guidance

navigational system) guides the missilefrom the ITCP to the target. TheTERCOM system compares informationabout the land terrain relief stored in thecruise missile's computer memory withthe actual terrain it is flying over.Various altimeters collect the actualterrain relief data. The missile's positionis determined and commands are sent toan automatic pilot which corrects thecourse. Digital maps of terrain areas arecompiled by first digitizing the height ofa point on the earth's surface whose

coordinates are known. Adjoining pointsare then established, assembled into adigitized map of the area, and stored inthe memory of the cruise missile'scomputer.


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REFERENCES

General references on missiles:

Baar, J., and W.E. Howard. Polaris, 1960.

Beard, Edmund. Developing the ICBM, 1976.

Cohen, William S., Secretary of Defense. Annual Report to the President and the Con-

gress, 8 Feb 00 outlines DoDs programs for the coming year,

http://www.dtic.mil/execsec/adr2000/adr2000.pdf(in .PDF format)

- Chapter 8, Nuclear Forces and Missile Defenses (9 pages)

- Appendix D-1, DoD Strategic Forces Highlights (1 page)

Collier's Encyclopedia, Crowell-Collier Publishing Company, 1963, Volume 17.

Gatland, Kenneth. Missiles and Rockets, 1975.

Neufeld, Jacob. Ballistic Missiles in the United States Air Force, 1945-1960. Office of

Air Force History, United States Air Force: Washington, DC, 1990

Pegasus. Facts On File, Inc.:Facts on File World News Digest, 1990.

Space and Missile Orientation Course Study Guide, 4315 CCTS/CMCP, Vandenberg

AFB, CA, 1 June 1992.

Strategic Missiles,Air Force Magazine, May 1993.

US Strategic Command, Offutt AFB, NE, 6 Jul 00, http://www.stratcom.af.mil

- The Forces has links to strategic weapon systems and bases

- Fact Sheets has links to strategic weapon systems

General references on nuclear effects:

Comprehensive Study on Nuclear Weapons,United Nations Centre for Disarmament,

report to the Secretary-General, Vol 1, New York, 1981.

Hansen, Chuck. U.S. Nuclear Weapons: The Secret History. New York, Orion Books,

1988.

McNaught, L.W. Nuclear Weapons & Their Effects. New York, Brassey's Defence

Publishers, 1984.

Tsipis, Kosta. Arsenal: Understanding Weapons in the Nuclear Age. New York, Simon

and Schuster, 1983.


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http://www.dtic.mil/execsec/adr2000/adr2000.pdfhttp://www.stratcom.af.mil/http://www.stratcom.af.mil/http://www.dtic.mil/execsec/adr2000/adr2000.pdf


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ICBM-related Fact Sheets/Summaries:

20th

Air Force, FE Warren AFB, WY ICBM component of USSTRATCOM,

http://www.warren.af.mil/20af/default.htm

91st

Space Wing, Minot AFB, ND representative of the 3 ICBM wings,

http://www.minot.af.mil/base/squadrons/91sw.html

USAF Fact Sheet, Atlas E, Office of Public Affairs, Hq Air Force Space Command,

Peterson AFB, CO, Nov 91.

USAF Fact Sheet, LGM-30G Minuteman III, Public Affairs Office, Peterson AFB, CO,

Aug 99, http://www.af.mil/news/factsheets/LGM_30_Minuteman_III.html

USAF Fact Sheet, LG-118A Peacekeeper, Public Affairs Office, Peterson AFB, CO, Oct

99, http://www.af.mil/news/factsheets/LG_118A_Peacekeeper.html

SLBM Submarine Fact Sheets/Summaries:

Fleet Ballistic Missile Submarines, Dept of the Navy, Washington, DC, nd,

http://www.chinfo.navy.mil/navpalib/ships/submarines/centennial/images/ssbns_new.pdf

Fleet Ballistic Missile Submarines SSBN,Dept of the Navy, Washington, DC, 21 Sep

99, http://www.chinfo.navy.mil/navpalib/factfile/ships/ship-ssbn.html

Submarine Operations Today(slides), Dept of the Navy, Washington, DC, nd,

http://www.chinfo.navy.mil/navpalib/ships/submarines/centennial/subops/index.htm

Trident I (C-4) Missile and Trident II (D-5) Missile,28 Apr 00,

http://www.sublant.navy.mil/weapons.htm#C-4and

http://www.chinfo.navy.mil/navpalib/factfile/missiles/wep-d5.html

Impact of Strategic Disarmament on Missiles:

The Anti-Ballistic Missile Treaty (full text plus agreed statements, understandings, and

protocols), http://www.state.gov/www/global/arms/treaties/abmpage.html

START III at a Glance (fact sheet), Arms Control Association, Washington, DC, Jan 99,http://www.armscontrol.org/FACTS/start3.html

Treaty on the Further Reduction and Limitation Of Strategic Offensive Arms (START II)

fact sheet, Bureau of Public Affairs, US State Dept, 20 Mar 96,

http://www.state.gov/www/regions/nis/russia_start2_treaty.html


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http://www.warren.af.mil/20af/default.htmhttp://www.minot.af.mil/base/squadrons/91sw.htmlhttp://www.af.mil/news/factsheets/LGM_30_Minuteman_III.htmlhttp://www.af.mil/news/factsheets/LG_118A_Peacekeeper.htmlhttp://www.chinfo.navy.mil/navpalib/ships/submarines/centennial/images/ssbns_new.pdfhttp://www.chinfo.navy.mil/navpalib/factfile/ships/ship-ssbn.htmlhttp://www.chinfo.navy.mil/navpalib/ships/submarines/centennial/subops/index.htmhttp://www.sublant.navy.mil/weapons.htmhttp://www.chinfo.navy.mil/navpalib/factfile/missiles/wep-d5.htmlhttp://www.state.gov/www/global/arms/treaties/abmpage.htmlhttp://www.armscontrol.org/FACTS/start3.htmlhttp://www.state.gov/www/regions/nis/russia_start2_treaty.htmlhttp://www.state.gov/www/regions/nis/russia_start2_treaty.htmlhttp://www.armscontrol.org/FACTS/start3.htmlhttp://www.state.gov/www/global/arms/treaties/abmpage.htmlhttp://www.chinfo.navy.mil/navpalib/factfile/missiles/wep-d5.htmlhttp://www.sublant.navy.mil/weapons.htmhttp://www.chinfo.navy.mil/navpalib/ships/submarines/centennial/subops/index.htmhttp://www.chinfo.navy.mil/navpalib/factfile/ships/ship-ssbn.htmlhttp://www.chinfo.navy.mil/navpalib/ships/submarines/centennial/images/ssbns_new.pdfhttp://www.af.mil/news/factsheets/LG_118A_Peacekeeper.htmlhttp://www.af.mil/news/factsheets/LGM_30_Minuteman_III.htmlhttp://www.minot.af.mil/base/squadrons/91sw.htmlhttp://www.warren.af.mil/20af/default.htm


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Text, statements, analysis by Carnegie Endowment for International Peace, Washington,

DC, http://www.ceip.org/programs/npp/start2.htm
http://www.ceip.org/programs/npp/start2.htmhttp://www.ceip.org/programs/npp/start2.htm

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