# Ballistic Missile question

A few months ago I was looking at the distances between various places, and it occured that it took nearly 80 years for the first intercontinental plane to come online, but a scant 15 years for the first ICBM. Somone mentioned that with BM’s increasing the maximum height evcen slightly increases the range greatly. So question, if a ballistic missle is given some extra fuel (lets say another stage is added) then would the range be greatly increased, since it could go to a higher height? And secondly if the previous is true, then how dose increasing the height increase the range?

I’d think you were misremembering. More likely it was increasing the diameter. That would enable a much more voluminous fuel tank; V=hπr². You’re not giving much to go on. :dubious:

Heck, build them with sufficient stages (say three) and sufficently strong engines and you throw throw stuff to the moon with them.

Sorry I phrased it poorly. I meant the maximum height to which a BM travels in flight above the surface of the earth. As opposed to its physical height.

Sorry I phrased it poorly. I meant the maximum height to which a BM travels in flight above the surface of the earth. As opposed to its physical height. How dose the maximum altitude achieved impact on range? Woukd say sending it to (and the altitudes are conjecture, I am no expert so excuse me if this is incorrect) an altitude of 120 KM as opposed to 100 KM increase its maximum range at all?

The first few minutes of an ICBMs flight is known as the boost phase, which is the phase it sounds like you’re talking about extending. Ending that phase higher will put the midcourse phase at a higher suborbital altitude, making it closer to a true orbit (less air resistance, more assistance due to the falling effect of orbit).

For a real world example of a nonpropelled object going farther (faster) when it’s started from a greater height, look at a pitcher’s mound. Now, it’s true that a ball thrown off a cliff would have its velocity in the horizontal direction become almost insignificant compared to the vertical velocity, but this isn’t true for objects that have either lift or thrust (use a glider for a real world example).

What? You’re saying the first intercontinental plane rolled out in 1983? I’m sure I flew to Europe and back a couple of times in the 1970s so we must have had them by then.

Intercontinental as in practically anywhere in the world unrefueled from anyother place. That was not possible until the 777.

What happens when the BM hits the fan?

Nitpicky point, although it doesn’t affect the substance of your point:

If you’re referring to early versions of the 777, the Airbus A340 had similar or better ranges a decade earlier. If you’re referring to the 777-200LR, the current record holder for a single journey (Hong Kong to London non-stop with a tailwind), the aircraft is only rated for 700 km further than the latest Airbus A340, the latter of which doesn’t suffer the same path restrictions (ETOPS) of the two-engine 777.

Actually I am certain that Karachi to Houstan is the current record holder. Pakistan International had four flights a week in a 777. Or did until Department of Homeland Security decided it was an security hazard airline.

You are confusing scheduled flights with an experimental flight. The 777 holds the record for the longest nonstop flight, and it was indeed from Hong Kong to London - the long way. That is, the aircraft crossed the Pacific, North America and the Atlantic before landing in London.

It wasn’t a revenue flight, though. I’m not sure what the current longest revenue flight is.

PIA’s website still lists flights to the USA, so presumably the FAA (not DHS) still considers it to safe.

These are via stopover in London or Shannon.

First of all, I’m not sure where the o.p. gets the 15 year estimate for ICBMs; rockets have been used in military applications since the 17th Century, and the era of modern controllable, multistage rockets began more or less with Konstantin Tsiolkovsky (Russia, starting late 19th Century), Robert Goddard (US, ~1910), and Hermann Oberth (Germany, ~1915). So even for the modern era, ICBMs, which came on line with the Russian R-7 and American SM-65 ‘Atlas’, both first deployed in 1959. Neither, which used liquid cryogenic fuels, was especially suited to ICBM duty (requiring close to an hour or more of fueling and preflight operations, remaining in operational state for only a few hours after fueling, and being highly vulnerable to attack), although both went on to serve for decades as the basis for space launch vehicles for satellites, interplanetary probes, and even man-rated vehicles (Mercury-Atlas, 8K72K Vostok, 11A57 Voskhod, and 7K-OK Soyuz).

Both the US and (much) later the Soviet Union gravitated toward solid rocket boosters because, despite their lower per mass of fuel performance (called specific impulse or I[sub]sp[/sub]) they are more simple to maintain, easier to keep at ready, and more generally robust than fueled liquid rockets. (The Atlas, in fact, was not self-supporting; in order to reduce weight, it used “balloon tanks” made of thin stainless steel which required pressurization in the fueled condition for structural support, and special structural jigging when unfueled.) SRBs trade performance for simplicity, but it was a long development process to be able to ‘pour’ solid motors reliably to get consistent performance, the motors require constant environmental conditioning to prevent propellant flaws, and large SRB motors can be difficult to handle and transport, being essentially many tons of aluminized explosive.

All things being equal, making a rocket longer or wider in diameter will, by virtue of adding more fuel, give it a higher altitude and a longer terminal range. However, this being in the domain of rocket science and orbital/suborbital ballistics, it’s not merely an issue of linear scaling. There are numerous factors that go into determining optimum (or at least, suitable to the mission) configuration of a rocket. For instance, the wider you make the rocket, the more frontal aspect it has, and thus the more air resistance it experiences going up, thus requiring more fuel. Making it tall and skinny, on the other hand, causes it to both see high lateral aerodynamic loads and decreases bending mode frequencies, which can result in overstressing joints in motors and interstages. There is also the issue of controllability; you want the missile center of gravity (CG) to be as far forward as possible, giving a longer control moment arm, which means that whatever system you use for thrust vector control (TVC), be it jet vanes, inert liquid injection, vernier motors, gymboling nozzles, or whatever doesn’t have to work as hard to keep the rocket pointed up. (Think of balancing a pencil on your fingertip; now try doing it while running across an unpaved hiking trail. This will give you some sense of what a feat this actuallly it.)

And then there is staging; all modern ICBM- or orbit-capable rockets use multistage motors, thus allowing them to reduce dead weight (increasing net performance) and also optimize the nozzle parameters for the range of altitudes in which it operates. (A few systems use nozzles than can adjust somewhat for changing conditions, but so far no operational system has employed a truely variable parameter nozzle like a plug or aerospike nozzle.) You don’t just pull a bunch of motors off the shelf and randomly stack them one atop another–well, at least, not mostly, and usually not too successfully. For the most part, motors are designed to be integrated into a final booster design so as to maximize the capability of that design within its physical and payload envelope, although the desire to use deprecated ICBM motors the mixing and matching of surplus motors for space launch, targets, and sounding rockets has led to this sort of application, where the sometimes suboptimal performance (compared to a purpose designed booster) is offset by inexpensive motors and heritage handling and processing equipment.

As for range, this is dictated by terminal altitude, but again not in linear fashion. You may remember from high school physics that ballistic objects travel in parabolic trajectories (if you ignore air resistance); this is true of ballistic missile payloads, too, but with the further complication that the ground below is both curved down toward the horizon and spinning. As a result, a little bit of extra height from increased performance can give significantly more range; compared the range and throw weight capabilities of the USN Fleet Ballistic Missile Trident C4 to the Trident II D5; the latter has substantially more throw weight and about twice the terminal range for comperable trajectories. Push a missile high enough and it’ll put a payload in orbit, from which it can reach anywhere (with a little reverse thrust) under its orbit and off to the side based on whatever orbital correction or re-entry cross range the post boost system can muster. This is the premise of Fractional Orbital Bombardment Systems (FOBS), that you could fire from some remote corner of the world that is not observed by early warning systems, fly your payload over an unsuspecting target, and drop it down in a quick terminal jog before anybody knows what happened. Fortunately, modern DSS satellites can detect launches anywhere in the world almost real-time and FOBS is prohibited by treaty (though it would be easy enough to implement in practice using an orbital-class launcher and relatively straightforward satellite maneuvering propulsion and avionics sysstems). Also, you’d prefer to launch with the spin of the planet to maximize range (though most ground based US and USSR ICBMs flew in near polar orbits because it is the fastest great circle trajectory to target); for space launch, retrograde trajectories (against the Earth’s rotation) are very rarely done because it reduces payload capacity to orbit.

Because most ICBMs are constrained by some kind of physical envelope–say, they have to fit in an existing silo system like LGM-118A ‘Peacekeeper’, or have to be roadable like the RT-2PM ‘Topol’, or fit inside a submarine hull that has to clear naviation hazards like the UGM-133A ‘Trident D5’–they’re often constrained in length beyond the structural and control issues described above. In order to improve performance and maximize termal range other methods are used, like extensible nozzles, drag reducing frontal aerospikes, conformal placement of payload in or around motors, ‘waverider’ gliding RVs, et cetera. At this point, most modern ICBM systems can place their design payload essentially any place on the planet that a threat might exist; Anarctica and New Zealand might be questionable (from a ground-based ICBM out of North America) but Europe, Asia, and Saharan Africa are all within reach, and of course submarine-based launchers can reach out and touch anybody–even rogue terrorist penguins–with a few days notice to get on station.

Regarding the ICBM versus aircraft question, I’ll just note that while the missile only has to make one flight and a large part of it gets chucked away within the first couple of minutes, the aircraft is usually expected to go there and back and remain intact, and is also not designed to see the wide range of agressive environments a rocket will withstand (albeit only for a few minutes). It’s also true that the final payload carried by a suborbital booster is equivilent to only a handful of passengers and their luggage, compressed to fit within a small aeroshell, and exposed to thrust and aero loads that would severely injure or kill a human being. Aircraft are actually more efficient compared to rockets in terms of the amount of thrust per mass unit of fuel carried, mostly because they extract their oxidizer from the atmosphere where a rocket has to carry it along, but also because the flow rate is slower, and so thermodynamically more of the energy is used in thrust versus a rocket which loses a lot of energy in its brillant, resounding plume. On the other hand, no aircraft will deliver you from Wyoming to Smolansk in under thirty minutes, even if there were a demand for such a service.

So…more than you ever wanted to know about ICBMs. And yet, still the most productive half hour of my day.

Stranger

Thanks sir.

I figured it was from the V2 to probably the atlas or Titan, everthing forward from that seems to be evolutionary adaptations for Ballistic Missiles.

Declan

I’m not sure about that, having read it I find that I suddenly wanted to know all of that Thanks.

Fascinating subject! And excellent post, Stranger! I thought both the Peacekeeper and Minuteman II as well as some of the old Soviet missiles used as late as 2005 were still liquid fueled, so I have learned something today!

According to the gospel that is Wikipedia, the first ‘true’ ICBM was developed by our friend Werner von Braun of I Aim For The Stars (but missed and hit England) although not used, so arguably “15 years” of development should be more like 60+. The V2 was also a ‘ballistic’ missile although it was not Intercontinental.

Also for the curious:

[QUOTE=The same source
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Land-based ICBMs
The U.S. Air Force currently operates 500 ICBMs around three air force bases located primarily in the northern Rocky Mountain states and the Dakotas. These are of the LGM-30 Minuteman III ICBM variant only. Peacekeeper missiles were phased out in 2005.[6]

All USAF Minuteman II missiles have been destroyed in accordance with START, and their launch silos have been sealed or sold to the public. To comply with the START II most U.S. multiple independently targetable reentry vehicles, or MIRVs, have been eliminated and replaced with single warhead missiles. However, since the abandonment of the START II treaty, the U.S. is said to be considering retaining 800 warheads on 500 missiles.[7]

MIRVed land-based ICBMs are considered destabilizing because they tend to put a premium on striking first. If we assume that each side has 100 missiles, with 5 warheads each, and further that each side has a 95 percent chance of neutralizing the opponent’s missiles in their silos by firing 2 warheads at each silo, then the side that strikes first can reduce the enemy ICBM force from 100 missiles to about 5 by firing 40 missiles at the enemy silos and using the remaining 60 for other targets. This first-strike strategy increases the chance of a nuclear war, so the MIRV weapon system was banned under the START II agreement.

The United States Air Force awards two badges for performing duty in a nuclear missile silo. The Missile Badge is presented to enlisted and commissioned maintainers while the Space and Missile Pin is awarded to enlisted and commissioned operators.

Sea-based ICBMs
* The U.S. Navy currently has 14 Ohio-class SSBNs deployed. Each submarine is equipped with a complement of 24 Trident II missiles, for a total of 288 missiles equipped with 1152 nuclear warheads.

``````* The Russian Navy currently has 13 SSBNs deployed, including 6 Delta III class submarines, 6 Delta IV class submarines and 1 Typhoon class submarine, for a total of 181 missiles equipped with 639 nuclear warheads. Missiles includes the R-29R, R-29RM/Sineva and Bulava SLBMs (deployed on the single Typhoon SSBN as a testbed for the next generation Borei class submarines being built).

* The French Navy constantly maintains at least four active units, relying on two classes of nuclear-powered ballistic submarines (SSBN): the older Redoutable class, which are being progressively decommissioned, and the newer le Triomphant class. These carry 16 M45 missiles with TN75 warheads, and are scheduled to be upgraded to M51 nuclear missiles around 2010.

* The UK's Royal Navy has four Vanguard class submarines, each armed with 16 Trident II SLBMs.

* China's People's Liberation Army Navy has one Xia class submarine with 12 single-warhead JL-1 SLBMs. The PLAN has also launched at least two of the new Type 094 SSBN that will have 12 JL-2 SLBMs (possibly MIRV) which are in development.
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[/QUOTE]

The MIRV-capable Minuteman III and the Peacekeeper both used a storable liquid fueled post-boost maneuvering vehicle to place the individual RVs (3 Mk.12A for MMIII, up to 10 Mk.21 for PK) toward their targets; however, the main propulsion system motors for all Minuteman family and MX/PK vehicles (as well as the stillborn PK-derived MGM-134 ‘Midgetman’ mobile single RV booster) are all solid fuel motors, as are all US/UK Fleet Ballistic Missile (FBM) SLBMs (Polaris/Poseidon/Trident). The last liquid fueled ICBM fielded by the United States was the SM-68B ‘Titan II’ (using storable but highly toxic and corrosive UHMD/MMH and NiTet), deployed in 1963 to supplement and eventually replace the cryogenic fueled Titan I and Atlas ICBMs, and while the Titan II remained in operational deployment until 1987, the force only consisted of one wing of six squadrons (9 missiles per squadron), and while they carried the heaviest warheads in the ICBM fleet (the ~9 MT W53 in a Mk. 6 RV) they were vastly outnumbered by the Minuteman (~1000 vehicles of various configurations of the MM family) by the mid-Sixties. The Titan II force was decommissioned completely in 1987, owing to maintenance cost and hazard of the aging fleet, and also the questionable value of the high yield and low accuracy Titans versus the modern and highly accurate MIRV Minuteman III and Peacekeeper fleets. Peacekeeper has now been decommissioned, and the remaining Minuteman III fleet is equipped with single Mk. 21 RVs in compliance with START II, even though the treaty has not been ratified and the Russian Federation has announced intentions to withdrawal from some provisions of the treaty.

The Soviet Union favored liquids owing to both problems in developing and reliably building solid motor rockets, and because all things being equal liquid rockets offer greater performance. It wasn’t until the mid-Eighties that they started to deploy solid motor ICBMs (SS-24 ‘Scalpel’, SS-25 ‘Sickel’, and the post-Cold War developed SS-27 ‘Topal M’ and further evolutions therefrom), while the mainstay of their land force, the SS-11 ‘Sego’, the SS-18 ‘Satan’ and SS-19 ‘Stilleto’ comprised the bulk of their massive strategic missile arsenal throughout the bulk of the post-Sixties Cold War. They also deployed a variety of liquid fueled SLBMs (SS-N-6 ‘Serb’, SS-N-8 ‘Sawfly’, SS-N-18 ‘Stingray’, SS-N-23 ‘Skif’) which despite slower launch times had much larger throw weight and range than comparable USN FBMs (thus, permitting the Soviet to cover targets from north of the Barents and not requiring them to make through the G-I-UK SOSUS picket) and could be fired in full complement salvos rather than individually like the FBMs. The Russians still field the SS-N-23 today, and us a variant of it for space launch, as well as the later solid fuel missiles (SS-N-17 ‘Snipe’, SS-N-20 ‘Sturgeon’, and the SS-NX-30 ‘Bulava’); however, the trend is toward solid motors as they are less maintenance intensive.

One point of note is that longer range translates into less accuracy; absent of outside telemetry, the guidance systems rely on inertial measurements, in which errors are cumulative. This was a real problem with earlier analog systems, and even the advent of solid state rate-based systems precision was still about 0.5nm at ICBM ranges, and even that required secondary celestial measurements in the mid-course post-boost phase. Modern real-time embedded computing and sophisticated fluid-suspended gyros allow precision over that range to be measured within centimeters, far more accurate than the terminal trajectory of the ballistic RV can be calculated.

Here (PDF) is a brief summary of US strategic missile systems from the USAF’s ‘Air University’. If you go up a level there is basic info on orbital mechanics, nav and early warning systems, operational deployment, et cetera; enough to make your average man on the street the equal to a Cardinal Of The Kremlin-era Tom Clancy.

Stranger

Thanks, Stranger, must have been what I was thinking of. I remember hearing about a missile silo problem when I was in in 1992 or 3 where there was a problem with the hydrazine rocket fuel leaking into the silo itself and poisoning a bunch of guys so I guess I just assumed it was due to the missile being liquid fueled.