Look Out, Pyongyang? Rail Gun in the Works

One of the big selling points of the Navy’s new destroyer is that it can rain a whole lot of hell — 20 rocket-propelled artillery shells, in less than a minute — on targets up to 63 nautical miles away. Fully armed, two DDG1000s should have the firepower of an entire, 640-man artillery battalion, the Navy promises.
ddx_rail_1.JPGBut really, that’s the start. The ship’s real power will come when it moves away from chemical powders to shoot its projectiles — and starts relying on electromagnetic fields to shoot projectiles almost six kilometers/second, instead. With an electromagnetic rail gun pushing the rounds out so quickly, the number of rounds fired per ship would jump from 232 to 5000, Navy planners believe. (Military.com has a great primer on how it works.) Because they travel so fast — nearly Mach 7 — the destructive force those rounds deliver would more than double, from 6.6 megajoules to 17. And they would fly almost five times farther — up to 300 nautical miles. That’s enough to put 100% of targets in North Korea “at Risk” from a single battleship, a Navy briefing notes (right, sorry for the crappy scan).
No wonder the Office of Naval Research just handed General Atomics Aeronautical Systems a $9.6-million, 30-month contract for the preliminary design of an electromagnetic launcher, Defense Daily reports.
But don’t expect to see a rail gun around North Korea any time soon. The destroyer program is in flux. And the Navy isn’t looking for a “full-scale demonstration” of the rail gun until “around 2014,” DD notes. “If the acquisition community decides to place it on a ship it could be done around the 2019 time frame.”
Look out.
(Big ups: Haninah)

  • Joe Doe

    Im surprised that Military has not yet found a way to coat the electromagnetic railgun so it could withstand the pressures of shooting projectiles. With advances in nanotechnology and the ability to create diamonds in 12 hours I’m pretty sure a revolutionary form of alloy could be produced that would enable the electromagnetic properties to still function at the same time protecting it from the intense stress. A good example is the fusion reactor where they recently put a coil wire to control the perturbation from within the reactor. Maybe the design even though the most practical is not the correct design with the technology we currently have.

  • Mike

    What about stronger barrals, more powder? :D

  • Big D

    “What about stronger barrals, more powder?”
    Been done. Saddam was trying for that, actually.
    The problem is, it takes longer barrels, not just stronger ones, if you’re going to burn more powder in them. EM gives you a few orders of magnitude of velocity/weapon size.
    Also, one really nice thing about EM guns is that the shells shrink. Instead of a big shell and lots of powder, you use a small shell and a few gallons of gas to generate the electricity for it. That means you can carry a heck of a lot more ammo with less danger.

  • Eizu

    Keep in mind that the they will still need to keep some of their big artillery guns on board, for the same reason that infantry squads need a m203 grenade launcher. A rail gun is a line of site weapon only, and they will still need something that can be ‘lobbed’, considering how mountainous North Korea is.

  • Brian

    The previous two comments are quite ill-informed.
    1) Yes Virginia, you CAN lob a rail gun round. If anything, it’s a hell of a lot easier to lob it than it would be a conventional round. It’s still just a piece of metal going forward, so you can lob it just as you would a normal shell. However, you’ve got an advantage because you can regulate the amount of electricity going into the gun, thus allowing you complete control over the speed at which it leaves the barrel. You can’t do that with a conventional shell unless you want to take it apart and remove propellant before you shoot.
    2) An old battleship has far higher maintainance and operations costs than a DDX. Even if you use automated guns, you’ve still got a far larger crew operating the battleship. That means more paychecks to sign, and more retirements and benefits you’ll have to pay. Not only that, but the electrical systems, engine systems, and space availability on a battleship are WOEFULLY inadequate for the needs of a rail gun system. There’s a reason the DDX uses an all-electric engine. It’ll need that power for the rail gun to operate. You’d have to strip EVERYTHING out of the battleship and put in a brand new power and propulsion system for a rail gun to have even a hope of functioning. Finally, part of the cost on the DDX is that it’s a tech development platform. The Navy has already made the decision to develop the new tech, and the DDX is merely the system that gets saddled with the bill. They’re going to reuse much of the design (and thus save a lot of money) on later ships. If you simply refit a battleship, you don’t get that benefit.

  • Postie

    Ok, sounds cool and all, and I’d love to see it and keep in mind I’m not a military expert, but…
    Destroyers are small ships right?
    5000 rounds a minute is pretty quick and depending on the size of the rounds, that could take up alot of space. How many minutes of that could they do with out having to resupply the ship?
    Oh, and the NK’s are nuts if you ask me, by the time this rolls around, who know’s if they’ll even be there.

  • Connor

    Other thing people tend to forget is the soldier factor we need more masturbation time to fight well and this rail guns will give us that much needed extra masturbation time . Thank you.

  • Jerry

    I’ve work for the defense industry – The Air Force has had a slow launch, high velocity rail gun for about a decade, the problem has always been putting the package into a usable form. It takes an immesne amount of electricity to launch any projectile with EM forces, so its very expensive. The last I read up on it, they were discussing using chemical laser technology to produce instant electrical discharge into the rail gun. But it is a working device, with a tungsten dart and alumnium-alloy cartridge. it was discovery channel a while back. And while the Navy may put money into a project like this, remember they also control NASA to some degree, making this project a bit more interesting if you consider putting one of these into space. The potential for firing a non-explosive dart from space is quite disturbing, but effective. I think the hard part is getting additional payloads of ammunition into space cheaply before we ever implement any kind of space based weapons program above and beyond the existing systems we’ve got in place. As for putting an EM gun on a ship. That will take some doing, and could easily fry a ship’s circuitry. the whole thing is steel, and the EM forces required to launch will disrupt the steel, and all the electronics around it temporarily, unless they make the whole thing hardened. Very very expensive.

  • Not A Dumbass

    >”Keep in mind that the they will still need to >keep some of their big artillery guns on board, >for the same reason that infantry squads need a >m203 grenade launcher. A rail gun is a line of >site weapon only, and they will still need >something that can be ‘lobbed’, considering how >mountainous North Korea is.”
    Um… no. A rail gun projectile will follow a curved path.
    >”Im surprised that Military has not yet found a >way to coat the electromagnetic railgun so it >could withstand the pressures of shooting >projectiles. With advances in nanotechnology >and the ability to create diamonds in 12 hours >I’m pretty sure a revolutionary form of alloy >could be produced that would enable the >electromagnetic properties to still function at >the same time protecting it from the intense >stress. A good example is the fusion reactor >where they recently put a coil wire to control >the perturbation from within the reactor. Maybe >the design even though the most practical is >not the correct design with the technology we >currently have.”
    What you’ve just said is one of the most insanely idiotic things I have ever heard. At no point in your rambling, incoherent response were you even close to anything that could be considered a rational thought. Everyone in this room is now dumber for having listened to it. I award you no points, and may God have mercy on your soul.
    A railgun needs two things… a way to keep the projectile aligned while it’s accelerated, and two different conductor rails to provide the EM field. Way too complex for a gun tube which would need to be cylindrical and rifled (if not a smoothbore).

  • jimbo

    Why does this have to be a weapon? If the technology is here and understood, and the only problem is making it smaller and cheaper; then why don’t we build a big bulky one first to shoot rockets (‘er non-rocketed rockets) into space? We have plenty of space on land. We can have a nice spacious nuclear reactor with acres of capacitors; and with no fuel being carried into space the “space capsules” would be massively smaller and lighter. And on top of that the rail gun technology will have a chance to prove itself and develope. Lets think outside the box soldier guys. It’s not all about the biggest gun.

  • .

    “why don’t we build a big bulky one first to shoot rockets (‘er non-rocketed rockets) into space?”
    Do you have any idea how much accelleration you’re talking about? It’s one thing to accellerate a hunk of metal from 0 to mach 7 in under a second, but humans or sensitive electronics? There’d be nothing left.
    I believe Jules Verne purposed a similar system for reaching space using cannons. It’s now a homework problem in Physics 101 textbooks — the question being, “Would the accelleration of being launched into space by a cannon kill you?”. If you do the math (which is amazingly simple), the answer is “Yes. Many times over.” We’re talking about forces on the order of 200 G’s. Just about the only thing that can survive that is a hunk of iron.

  • penetrode

    If they really wanted to,
    couldn’t the chinese just fire one of their “sunburn” missles at a US naval ship?

  • Lewis

    Funny thing is… while ships can carry railguns which will be pretty destructive in the future… the land based one’s will make those look like a pea shooter. This is because they will not be constrained by space and layout limitations. when other countries develop these weapons no destroyer will be able to get near them… that’s why we are really already building them in subs :)

  • wongba

    in response to penetrode:
    and why on earth would the chinese want to do that? the US is worried about a north korean missile launch, not a chinese launch. or did u confuse chinese with north koreans because they’re all just a bunch of sneaky asians?

  • idintdoit

    The gun shoots metal pellets at mach 7 – that’s a hell of a lot of momentum even for small projectiles. If they’re too massive, the entire ship will get such a recoil it’ll wind up hitting Taiwan.

  • ++Don

    Regarding using a rail gun as a space launcher, another problem besides the tremendous acceleration that the payload would need to endure is that such a scheme would result in an orbit whose perigee is the launch point. You need to fire a rocket when the payload is on the other side of the earth (aka at apogee), in order to raise the perigee.

  • angrycat

    idintdoit, Joe Doe: If you know nothing, it’s best to just keep your mouth shut.
    idintdoit: Current 127mm naval arty shells travel at about Mach 3. Do you see many ships flying backwards when firing their guns? So why would doubling the speed of the shell make any difference?
    Joe Doe: I have no idea what you’re even trying to say here.

  • Daniel

    Anyone else think they’ve been playing too much metal gear solid?

  • Robert Bieber

    idintdoit, have you ever heard of the law of conservation of momentum? Within a system, the sum of the products of the velocities and masses of each of the objects will always remain constant. Now, given that the battleship is many, many orders of magnitude more massive than even a huge artillery shell, the negative change in the velocity of the battleship resulting from the positive change in velocity from the shell will be far less than negligible.

  • Nick

    The physics he describes is right, but the conclusion isn’t. Sure the round is moving fast, but the mass of the round is so small relative to the mass of the ship that firing the round won’t affect the ship much.

  • Jay

    1) Is the physics problem for putting a rail launched person into space, “How long would the rail need to be at a constant 9g acceleration, to acheive orbit?”
    2) If such an orbit was acheived, could you then use chemical rockets to obtain the correct orbit?
    And no, I won’t talk about wonder diamond alloys, but it occurs to me if the module has to touch the rail gun, you’re gonna get a lot of heat.
    My science fiction book would invent the mag-lev really long rail gun to get Tom Swift into space.
    The first two questions were serious, the last two statements acknowledge the fact I need to ask, ’cause I don’t know.

  • ch4rm


  • jimbo

    This is not quite the same as a cannon. The energy transfer is not instantanious. And we can always make a mile long track, accelerating the shuttle within suitable stresses. The Track can then curve upwards, perhaps along the side of a mountain. And if we only use it on un-maned missions it would be worth it. And even if it can’t get us all the way there we can strap on a rocket booster. It’s still better than burning millions of gallons of fuel. It can work like a bullet train, if that is more efficient, then transfer over to a more powerfull rail gun type track.

  • x

    Let’s spend a 5 billion dollars so we can take out people with AK-47s and Scuds. Cause no one will ever mess with us if we have a better military than them.

  • ralph

    How about one rail gun shot aimed directly at “Dear Leader” “Great Leader” or “Dork Leader” as they savages North of the 38th name their leader[s]. Pity is, as brain damaged as he is the USA cowers at his every utterance and then submits to his blackmail with money, technology, or worse. So whether he’s done in with a “rail gun”of a .44 Magnum, let’s deal with him. Mickey Mouse would make a great replacement for this little runt.

  • ralph

    How about one rail gun shot aimed directly at “Dear Leader” “Great Leader” or “Dork Leader” as they savages North of the 38th name their leader[s]? Pity is, as brain damaged as he is, the USA cowers at his every utterance and then submits to his blackmail with money, technology, or worse. So whether he’s done in with a “rail gun” or a .44 Magnum, let’s deal with him. Mickey Mouse would make a great replacement for this little runt.

  • Guest

    Or, we could just give them some GODDAMN FOOD! The current, belligerent policy towards North Korea is a total failure.

  • shaun

    “Or, we could just give them some GODDAMN FOOD! The current, belligerent policy towards North Korea is a total failure.
    Yes, because they are hungry and that is why the NK are a military threat.
    Have you learned nothing from history? Little, if any, of the food ever gets to those who are starving. Not that that is even the issue here. Do you think if we airdrop some Big Macs to NK that they suddenly would be unwilling to launch a nuclear missile at US forces? WTF?, over.
    Weapons like rail guns will give us the ability to surgically remove a military threat rapidly even better than cruise missiles and laser guided bombs. If it allows our military to get the job done more efficiently and effectively then I’m all for it.

  • Matt S

    The military.com article (http://www.military.com/soldiertech/0,14632,Soldiertech_RailGuns,,00.html) did not have a date, but it said that the Army was going to have a test system in 2005. I wonder what the current date for that test is. (Yes, I just assumed that it did not meet the test date.)

  • Surfed on

    Um, actually your ill-informed. Propellant for artillery comes in charges known as “bags” so you can regulate the bang behind the boom. FYI

  • Bill K

    Would it surprise anyone to know that I have a Geography book from the late 19-teens with a conceptual picture of soldiers firing a rail gun on French forces (if I remember correctly)? I was dumbfounded to find out that the rail gun concept had been around that long. I scanned the picture to send to a friend if anyone wants to see it.

  • Phaedrus

    Smashing things, and threatening to smash things with guns of any sort is a poor way to create workable relationships with nations, no wonder the NKs are working on gadgets! In the atomic era the ability to blast an Nth area, with powder guns, rail guns, or fission bombs, can create only a standoff. So why build rail guns? follow the money…

  • Nestor

    As for the refit BB’s argument it would be quite costly, when we last updated them there was a possible plan to replace on of the turrets with a VLS system, never got off the accountants book’s just added some box launchers.
    As for the use more powder, answer look at HARP
    which also shows the the G load of a EM round is not an insurmountable problem
    one great thing about EM vs Chem lauch will be a much higher magazine storage capacity and reduced change of magazine or turret fires.

  • Jeff_F_F

    That time frame appears to have been compressed. The Navy just test-fired an 8 Mj demonstration gun and has awarded a contract for a 32 Mj gun. http://www.ga.com/news.php?subaction=showfull&id=1151686612&archive=&start_from=&ucat=&
    As to nuclear missiles, if you can hit any target in N. Korea with a guided mach 7 artillery round, why not make an anti-missile version.

  • john doe

    you guys are not seeing the bigger picture with a rail gun. no chemicals or oxygen or gravity needed to fire it. this is a weapon that could be applied to satelites or used in space easily. with all the solar energy available it would be perfect for a satelite to use if needed.

  • 502

    Good thing we are putting our new technology out for the whole world to know about.

  • adon

    Um if you have a non explosive kinetic round going down range at mach 7 it will have one hell of a range but the trajectory will be so flat that it will be usless against land based targets unless they are on very flat land with no hills infront to lob the shell over. You would have to have a HE, guided round for land based targets. These would be prone to failure from the high acceleration as pointed out earlier. Sounds like a sea/sea or surface to air weopon to me

  • Someone

    About what John Doe said up the top of the page, well doesn’t Pi=Pf? So if you fire a rail gun from a sattelite in space, theres no friction whatso ever around it and it will be launched off somewhere. This would actually be good for a probe travelling as it could get very fast with a rail gun attached to the back of it.

  • James M. Essig

    The U.S. Navy seems really interested in electromagnetic guns for its next generation destroyers. I have no doubt that they will be able to field an effective system as such sometime next decade.
    An interesting take on electromagnetic guns would be to develope projectiles reminescent of the approximately 1 metric ton projectiles fired from the 16 inch guns of the WWII era battleships. A 1,000 kilogram projectile hitting a target with pin-point precision at hypersonic velocities would be quite formidable.
    One might ask, for projectiles of that size, why not simply use a ballistic missle which can deliver such projectiles at a speed of several miles per second (about 4 miles per second in the case of a submarine launched ICBMs). The answer to this question is that a 1 metric ton electromagentic gun projectile as such would require no powder or chemical propellants thus enabling many more rounds to be stored within the ship’s magazine(s) thus promoting safe storage and handling while greatly enhancing the lethality of the ship by allowing it to destructively engage many more targets without the need to resort to the dangerous use of nuclear weapons.
    As a thought experiment, or really simply just a thought concept, as the limits of ability of the projectile to handle accelleration induced stress approaches infinity or the ability to uniformly accellerate the projectile so that it experiences no net accelleration induced stresses becomes perfect, the intensity of the electromagnetic fields (i.e., electrodynamic and/or magnetodynamic forces) accellerating the projectile approaches infinity, and the energy to accellerate the projectile reaches infinity, then the velocity of the projectile approaches and equals C, the velocity of light.
    Now obviously, there is probably little hope of humanity or any other existant intellegent civilizations within the universe of actually harnessing literally infinite quantities of energy, one can see that as improvements in the parameters for which the hypothetical limits suggested above were given continue to be made via improvements in material science, the ability to improve the uniformity of projectile accelleration induced stresses to reduce stress induced forces on the projectile, the ability to generate ever more intense electrodynamic and/or magnetodynamic fields, and the capacity to generate greater overall power levels within electrodynamic and magnetodynamic systems, the kinetic energy of projectiles in the atmosphere or in space as well as their rest mass specific kinetic energy densities will continue to improve.
    Now, it will be along time before we can launch macroscopic projectiles in an electromagnetic gun at velocities approaching C, but I would not be surprised if we can reach muzzle velocities of between 10 and 20 kilometers/sec over the next few decades especially for space based systems where air friction is non-existent.
    As for encasing the projectile in some sort of material such as diamond or some other material of high bulk modulous, high elastic modulous, and of high strain properties, carbon nanotubes might be the perfect answer espcially with improvements in industrial output of high quality materials.
    That’s all for now.
    Best Regards;
    Jim Essig

  • James M. Essig

    One further comment I might add regarding naval electromagnetic guns.
    Perhaps the energy storage mechanism for rapid energy release to power the rail guns inorder to send a barrage of heavy projectiles toward a given hard but dispersed target in a timely nearly simultaneous manner would be to have a stored energy mechanism composed of counter-rotating flywheels with outer rotational velocities on the order of a few kilometers/second wherein the flywheels would each have a mass in excess of a few hundred metric tons.
    For a softer flywheel, in case of partial disintegration, the materials of construction could of a Kevlar/Graphite fiber construction or perhaps even the new material called Zylon which I believe has a tensile strength of at least twice that of Kevlar.
    Now granted, a complete distintegration of a turbine rotating at that speed would be like 100 tons of TNT exploding and thus would be catastropic for the vessel and its crew, however, I think properly designed turbines made of zylon could operate within safety parameters at those rotational velocities. If not, then perhaps a material with a greater strength to wieght ratio could be or will be developed in the future for such a purpose.
    Note that a turbine with a mass of say 300 metric tons having an outer rotational velocity of about 3 km/sec should be utilizable to launch 300 1 metric ton projectiles at a target wherein all of these projectiles could be launched in a matter of a dozen or so seconds. Obviously, the projectiles could have flight paths designed for simultaneous impact on a single target or for simultaneous lighting strikes on several to dozens of key targets. Talk about warship combat altering paradynms!!
    Given the great potential of electromagnetic naval guns, I can see why the U.S. Navy is very interested in this subject. In an era of evolving terrorist strike methods and mobility, such ships could be a valuable asset to our national security, and ultimately to the security of the global community as well.
    Best Regards
    Jim Essig

  • James M. Essig

    It is interesting to note the hypersonic projectiles, be they of the size being investigated for the Navy’s new destroyers or the conjectured 1 metric ton projectiles I suggested, could probably be used to take out flush to surface missle silos. Given that the approximately 5 to 10 kg antitank “dart” fired from an M1-A2 Abrams Tank can punch its way through probably any tank armour on Earth, I can well imagine the directed kinetic energy effects and extremely high momentum effects of a hypersonic round within the rough order of magnitude mass range of 100 kg to 1,000 kg. I can even envision that a suitably hard and dense hypersonic 1,000 kg projectile hitting a flush to surface or a slightly buried hardened shelter like those built by Saddam in pre-war Iraq could be demolished or at least rendered inoperable by the impact of one of these proposed rounds. A suitable 100 kg round impacting at 3 km/sec should be able to do the same becuase of the highly directional nature of the rounds kinetic energy to target transmission.
    Best Regards;
    Jim Essig

  • James M. Essig

    Another notion occurred to me regarding the usefulness of electromagnetic guns.
    Suppose that there existed 1,000 electromagnetic guns sights located within the continental U.
    S. and that these electromagnetic guns were capable of launching 1,000 10 metric ton projectiles each within every one hour period on an emergency basis. Further, suppose that each projectile was composed of a dense refractory high strength core surrounded or encased in an even more refractory shell or coating and that the target collision velocity was on the order of 6 km/sec and the projectiles functioned as ICBM kinetic energy projectiles. That works out to be 40 megatons of collisional explosive energy in one hour or about 1,000 megatons delivered in 1 day or about 7,000 megatons delivered in one week of continuos firing. Bear in mind that 7,000 megatons is roughly 1/2 an order of magnitude greater explosive energy then our currently on active alert strategic nuclear stockpile. Moreover, the deploying of such a large number of smaller warheads would mean that at least for soft targets, the explosive energy would be distributed much more efficiently such as against general military base infrastructures, naval bases, population centers, economic targets, factories,etc.
    How might the electrical power be generated and/or stored to power such a huge kinetic energy round stockpile? The energy could in theory be stored in one 10,000 metric ton electrodynamic turbine with a rotational velocity on the order of 3 km/sec at each of the thousand stations wherein the turbine can be recharged with kinetic energy every 15 minutes upon firing of the salvos. This would yield 40 kilotons per hour of energy release per station. The turbines might be maintained in a spun up condition so that they can be utilized in an emergency situation.
    The turbines could be resupplied with kinetic energy by electrical motor drivers ultimately powered by vast gas turbine mechanisms which could utilize vast reserves of liquified natural gas whether the natural gas is extracted geologically or whether it is produced from our vast coal reserves, oil shale etc.. The turbines might alternatively have their electric motor drivers powered by coal, gasified coal, petroleum, alcohol or other biofuels, nuclear power, and/or solar energy to electrical energy conversion facilities.
    Now, granted, all of this is a little far out, but in theory, with proper economic incentive and the political will to move the backbone of our strategic defense away from a virtually entirely nuclear weapons based mode to a mixed mode utilizing kinetic energy based ICBMs and perhaps a couple of thousand nuclear warheads, some of which could be robust earth penetrating single nuclear warheads (preferably clean) of very high yield perhaps approaching 100 Megatons each for very hard, very deep target destruction if required, we might begin to shift our strategic deterent from the dangerously high nuclear stockpiles that we now maintain and for which the effects of radioactive fallout could still be far more destructive causualty-wise than the immeadiate effects of blast, thermal pulse, immeadiate ionizing radiation etc.
    The kinetic energy ICBM bases could be maintained in secured arrangements just as current U.S. Airforce based strategic assets are maintained.
    If we need stategic defense and we probably will require such for several to many decades to come, it is better that we reduce our ability to kill our own countrymen through radiation plumes generated by the impact of our nuclear weapons on the territories of our opponents. In the end, the survival of the human race may ultimately be at stake.
    Best Regards;
    Jim Essig

  • Professor Tanhauser

    Actually during WW2 they developed crude proximity fuzes that used miniature vacuum tubes, for god’s sake!
    They survived the shock of being fired from explosively propelled cannon, I’m certain modern electronics could survive the shock of firing from a gauss accelerator!
    BTW, don’t forget that some countries would build even more massive versions of these to keep out battleships away from their shores.

  • Jim DiGris

    1.If you have something in orbit, a simple retro rocket will cause it to re-enter the earth

  • James M. Essig

    Hi Jim;
    Thanks for the info on re-entry weapons with impact velocities of 6.5 km second. Also, it never occurred to me that the material out of which the projectile was made could be used as a component of a fuel air explosion upon vaporization.
    One can imagine numerous 1 million metric ton space darts assembled in orbit over long periods of time made from such materials having a diameter of less than 100 meters. The kinetic energy of impact would be around 5.25 megatons of TNT. Add to this the fact that fuel air explosives typically have peak yields of up to ten times greater than traditional conventional explosives and one obtains a yield per vaporized dart at about 15 megatons. For a single 10 million ton dart, the resulting yeild could be a staggering 150 megatons. However, both of these yeild values probably represent overkill since the typical yield of a modern strategic nuclear warhead is in the 100 kiloton to 450 kiloton range.
    Perhaps the material for such darts could be more economically derived from the surface or subsurface mineral deposits on the moon or from near Earth orbiting asteriods.
    Another option would be to develope numerous space dart interplanetary orbiting stations with orbits that are antiparallel to that of Earth. The resulting collision velocity would be about twice the orbital velocity of Earth (about 30 km/sec) around the sun thus yeilding a collision velocity of 60 km/sec.
    A one million metric ton dart with this collision velocity would yeild about 500 megatons. A 10 million metric ton dart would yield about 5,000 megatons or 5 gigatons which would probably be more than overkill. Very hard facilities buried underneath 2 or 3 miles of the Earth’s crust would perhaps be the only concievable targets for impactors in the several hundred megatons to 5 gigatons range. A 5 gigaton surface burst nuclear explosion would be expected to blast a crater about 7/8 mile deep in solid granite and so I can imagine that the directed kinetic energy effects of a 5 gigaton kinetic energy range impacter would demolish any such very deeply buried sites.
    Note that the NORAD facility under Cheyenne Mountain is only about 1,700 feet below the mountain’s surface.
    If additional velocity was required, perhaps non-nuclear rocket options for accellerating such huge projectile could entail deployment of huge solar sails made of very high mass specific solar energy reflecting membranes while the projectiles are a ways off in order to allow significant mass specific kinetic energy gains of the impactor(s).
    At any rate, impactors with kinetic energy ranges of one megaton are probably sufficient to hold any deeply buried hard targets at risk. In fact, impactors with 100 kilotons of kinetic energy may be all that is required to hold any deeply buried hard targets at risk becuase of the directed energy effects of such impactors and also because of the sheer power of the shockwave transmitted by such impacts to the subsurface material of Earth’s crust.
    Best Regards;
    Jim Essig

  • noodle

    Rail guns? I don’t think Amtrak should posses offensive weapons.

  • LtSmith 82nd.

    I would not be so surprised to find the US Military in contoll of such kinetic weapons on platforms in orbit already. The brilliant pebbbles program was in progudtion in the mid 80’s, and has not since been heard from. So what are the odds?? Pretty good. Have we used them??? thats a good question.

  • James M. Essig

    Hi LtSmith 82nd;
    That is an interesting conjecture considering that even non-classified public daily newspapers often made reference to the brilliant pebbles concepts. Once the hardware were to be fully designed, assembled, and lofted into orbit, I can see that such a program could be very cost effective for the defensive purposes it would serve.

  • Barton Foley

    Use of now retired battleships has come up a few times below.. I went through and figured some basic costs on it. Pretty interesting: Refitting the USS Missouri, for example, with suitable equipment to be an effective rail platform [nuclear plants, necessary electronic suite, native defensive systems, and three large turret systems] came out to somewhere in the range of $2 billion dollars. With systems bloat and the turret design figured an actual project would probably exceed $3 billion. Worth it? This is the United States Navy were talking about; you bet your ass.
    With several Iowa class boats being maintained in decent condition we could theoretically have 3 or 4 very large rail equipped battleships in service late 20’s or early 30’s for $20 – $40 billion. As for the cost effectiveness; as stated below the R&d is the major outlay and is already attached to other projects. With maintained hulls readily available, I think the return on investment would be very high and very secure, especially since these old boats were designed to take a major pounding by extremely heavy ordinance.
    Speaking of that, not included in the cost is a servicing or possible refit of the various armor belts. It might be worth the expense if a next generation weapon system were mounted, but I have no idea what the actual work would entail.
    Drawbacks would be antiquated hull design [though I think it was fast for its day], general age of core systems [B-52] and massive crewing requirements. Also, we’d have to retrain everyone on proper maintenance of a beautiful and historic wooden deck.
    Silly idea; one can dream. If me and five or six hundred friends win the lottery, you now know where the money will go.

  • James M. Essig

    A really interesting ultimate kind of rail gun would entail a system capable of accelerating charged particles to an energy at which they would become black holes based on the particle

  • Fredricksburg

    Not even the distant marches of our home could mask a terror like this for long. I’m afraid even of your brief comment here in this obscure little media, ages from the humanity you have seen. Remember Oppenheimer. Learn from what demons you have already created. Do not bring them with you. There is violence enough among the stars, and anyway they are not fitting dreams of such mysterious children.