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Hypersonic missiles are misunderstood
- jqpabc123 3y agoSummary: Space based directed energy (DE) weapons are the only thing capable of reliably intercepting hypersonic glide vehicles --- and the USA does not have them at this time.
- gerikson 3y agoBring back Star Wars, all is forgiven.
- clessg 3y agoSeems to be a reference to this: https://en.m.wikipedia.org/wiki/Strategic_Defense_Initiative https://en.m.wikipedia.org/wiki/Strategic_Defense_Initiative The 80s seemed like a blast, jealous!
- Arubis 3y agoThe money poured into this without effect was astonishing.
- gerikson 3y agoSome say trying to compete with it bankrupted the Soviet Union.
- mustacheemperor 3y agoThe author worked on this project, and does remark that the only way to power the jet-borne laser at the time was to essentially pack a liquid rocket inside a 747 - but advancements in laser tech over the last 20-30 years have created alternatives like solid state systems.
- paganel 3y ago> and the USA does not have them at this time. If the US would have still had smart strategists in positions of power we wouldn't have had to deal with all this hysteria about Russian hypersonic wunderwaffen. After all, how much damage can the Russians inflict with 10 or 20 or, let's say, with 50 such missiles? Not much, maybe they'll damage a building or two, maybe there will be some casualties on US soil, but not enough, and by a large margin, to win a war. Or, to put it another way, if the US were to militarily fold as a result of 50 such missiles hitting them on their home turf then they wouldn't have stood a chance anyway, hypersonic missiles or not. But this guy (otherwise pretty smart when it comes to tech) is not in the business of ensuring a strategic win for the US in a possible confrontation against Russia or China, he's in the business of selling his new tech (apparently some new laser gun?) and of making money for himself and for his investors. If it hadn't been clear, I'm ignoring the nuclear component in all this, as a Russian/Chinese nuclear hit on US soil, no matter the "transport" procedure (via "hypersonic" thingie or not) will very soon be matched by the US hitting Russian/Chinese soil in return. But, again, that's a totally different discussion to have, having "hypersonic missile" capabilities or not is quite orthogonal to it.
- zamnos 3y agoTen or twenty buildings on the continental US being hit by Russian hypersonic missiles may seem like basically nothing, but on 9/11 we lost two buildings, plus minor damage to the Pentagon, and the US collectively lost it's shit. It's still looking for it, more than a decade later. It's not the destruction from the Russian missiles I'm worried about, it's the US's totally unhinged response that I'm afraid of.
- paganel 3y ago> but on 9/11 we lost two buildings, Yeah, I'm aware of that, I also think that the US response was a huge strategic blunder, 20 years of Afghanistan and Iraq proved it.
- mensetmanusman 3y ago"We can rebuild Russia!"
- jandrese 3y agoHowever, it is not clear that the Russians have working maneuvering hypersonic glide vehicles. If they do, they may be too expensive and rare to actually deploy to the front lines.
- fauxpause_ 3y agoThe non-ballistic variety that Russia claimed was unstoppable has been stopped several time in the past couple weeks now that Ukraine has Patriot systems. Seems like they’re not really a big deal at all.
- up2isomorphism 3y agoWhat’s the point of reading a highly informative article written by a domain expert and then simply state your opinion by laying out wrong facts?
- the_af 3y agoAgreed. And the article goes in great detail of why a non-ballistic hypersonic projectile is so difficult to stop -- everything is going at extreme speeds and there's little to no time to maneuver, so if it deviates from the predicted trajectory you cannot intercept it at all. Why ignore all of the article? If a hypersonic missile can be intercepted by a Patriot, then it stands to reason it wasn't truly maneuverable, i.e. it was ballistic!
- fauxpause_ 3y agoThe article begins by referring to Russia using Hypersonic missiles against Ukraine, and then goes into detail about what defenses are necessary to defend against these weapons. It’s a good article. But the reality is that the Russian missiles making headlines don’t meet the specs of the article. Ukraine is shooting them down just fine using decades old technology.
- DiogenesKynikos 3y ago> Ukraine is shooting them down just fine using decades old technology. It is not publicly known whether this is true. The Ukrainians claim they shot down 6 of 6 Kinzhal missiles over Kiev in one night with a Patriot battery. In the available videos of the event, all that can be seen is that a few dozen air defense missiles were fired, and that something got through and struck the general location where the air defense battery was. A very healthy dose of skepticism is warranted about claims made in wartime by interested parties.
- programmarchy 3y agoIf we combine space lasers with runaway AGI…
- zorlack 3y agoULA: What if we're already falling behind in the orbital laser race?
- empedocles 3y agoI always enjoy hearing Tory Bruno talk tech. The key missing information here seems to be how many of these satellites would be required to have constant coverage of likely trajectories. This depends on the distance at which the laser remains effective. There would be no atmospheric scattering, but beam collimation is never perfect. It also depends on how fast the satellite can fire a new shot, as any warhead will be surrounded by decoys and other penetration aids. If this requires a large number of satellites, I am very sceptical. While Starlink has shown the possibility of creating large constellations, these sats would surely be much larger and more expensive. Really, Starlink makes me think something like BRILLIANT PEBBLES (https://en.wikipedia.org/wiki/Brilliant_Pebbles https://en.wikipedia.org/wiki/Brilliant_Pebbles) would be a more reasonable alternative. Also, could an adversary surround the warhead with absorbent chaff as a countermeasure? Or simply an ablative shield, the warhead needs one anyway to get through the atmosphere. Still, a very interesting read from a very interesting CEO.
- brucethemoose2 3y agoBrilliant Pebbles seems way more practical today than 1987. Lots of exotic 80s autonomous systems are now commercial and mundane, and launch costs are plummeting. Sending up a space laser seems particilarly absurd when one could send up 100(?) drone interceptors for the same cost with less R&D, especially when a drone constellation is far more resilient against anti satellite weapons.
- empedocles 3y agoI agree, though the cost of an exoatmospheric kill vehicle https://en.wikipedia.org/wiki/Exoatmospheric_Kill_Vehicle https://en.wikipedia.org/wiki/Exoatmospheric_Kill_Vehicle is probably high. And one way to avoid this is the other part of the hypersonic renaissance, which is the ability to dip down into the atmosphere.
- dsr_ 3y agoReferenced: cost of firing a laser is $1 of gasoline run through a generator. That's roughly a liter. Let's say raw energy content is 32MJ/L, and we have gasoline=>electricity losses of 50% and laser efficiency of 30%, so we expect a little more than 5MJ per shot. If you can hit a 2m target moving at 5Km/s through 1000Km of space and atmosphere with 5MJ, how much energy can you put on a 1m target moving at 7m/s at a range of 500Km? The difficulty in killing people from space will be targeting, and the limited availability of fuel and oxidator in space.
- boxed 3y agoThe article argues that lasers are cheap because you can just run them off a diesel generator in a container. But then it switches to space... which obviously doesn't do well with diesel and refueling. I assume we're talking about either battery+solar cell or nuclear power on those satellites?
- jandrese 3y agoAlmost certainly solar. The limitation isn't so much gathering the energy as it is keeping the thing from melting itself down. If you want to fire it more often you're probably going to have to put a bunch of these in orbit and maintain them indefinitely. Very expensive.
- varenc 3y agoThe important part is that their overall energy consumption is low. And their usage is quite bursty so I think you're right that a space based laser would just spend days charging batteries via solar or from an RTG. Also even on land with the diesel generator, I assume the generator is charging up batteries or super capacitors and not hooked up directly to the laser. Estimating a ~30 second laser discharge, only the most gigantic diesel generators can convert a gallon of diesel to electricity in half a minute.
- chrisco255 3y agoHow heavy would that battery/capacitor need to be in order to discharge 300KW laser pulses?
- SamBam 3y ago> And their usage is quite bursty so I think you're right that a space based laser would just spend days charging Sure, but surely there will be a maximum total power storage that a satellite will have, and if that totals, say, 50 missile zaps, them don't you have the same problem that the enemy could send 51? When 51 missiles are on their way, you don't have time to recharge from the sun. And unlike the diesel generator you can't quickly add more power storage the week before when you see what the enemy is about to do.
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- bombcar 3y agoThe missile knows where it is at all times. It knows this because it knows where it isn't. https://www.youtube.com/watch?v=nT1sSy39CuU https://www.youtube.com/watch?v=nT1sSy39CuU Now it is not misunderstood anymore, in fact, it understands you more than you know.
- dragonwriter 3y agoYou know, before we had interceptor missiles that were tolerably good against ballistic missiles, pretty much the exact same argument was made by experts like Edward Teller for why space based lasers and/or particle beams were essential to intercept ballistic missiles. Not saying its necessarily wrong now, but it was definitely very expensively wrong the last time.
- vertis 3y agoThe human genome project cost 3 billion dollars to sequence the first genome(s) (with one draft costing about 300 million), you can now have your genome sequenced for less than $1000. Yes there are differences, but science and technology have moved on substantially. Just because it was wrong the last time does not mean it is going to be wrong this time.
- dragonwriter 3y ago> The human genome project cost 3 billion dollars to sequence the first genome(s) Yeah, but (1) that’s orders of magnitude less than SDI, and (2) it actually did the thing.
- local_crmdgeon 3y ago"SDI failed" doesn't actually have a ton of evidence. If I built something like SDI, and I put it in HOE, the next thing I'd do is tell everyone else that it didn't work. We still don't know the content of a few shuttle launches, as well as many ULA launches. I think SDI was completed and functions.
- greedo 3y agoUmm, it's pretty trivial for amateurs to track space objects either in Earth orbit. For SDI to work, both the number and size of the systems would be quite large. And they would need to be replaced when they either fail or run out of station-keeping propellent. So no, there's no evidence for a "hidden" SDI that actually works.
- zzzeek 3y agoI've read most of this article so that I may bring you the money quote: "If you think hypersonic is fast, that’s nothing compared to the speed of light."
- ceejayoz 3y agoYou have to use a lot of light to impart 2,000 pounds of explosive's worth of damage to a hardened bunker, though.
- User23 3y agoHow about to lobotomize a bare human head?
- MobiusHorizons 3y agoIf you read the article, the laser is for intercepting missiles mid flight even if they are maneuverable.
- reportgunner 3y agoI heard that spinning the missile renders laser defense useless. I have not seen spinning the missile mentioned in this article, perhaps by intent of the author.
- dgritsko 3y agoTowards the bottom of the article... > Could platforms defend themselves? What if the warhead or missile was spinning, etc.? All those questions were answered. The only real barrier at the time was generating very high laser power levels in a way that was logistically practical in the field.
- rektide 3y ago"Just add three or four orders of magnitude to the power output and we're good to go!"
- aimor 3y agoIt's mentioned in this paragraph: "When we were developing this technology in earnest for missile defense 15 years ago, there were many theories about how it could be defeated. People thought that mirrored surfaces might just reflect the beam. It turned out that reflective surfaces are actually more vulnerable. Would the range be far enough? Maybe the atmosphere would scatter the beam too much? Could platforms defend themselves? What if the warhead or missile was spinning, etc.? All those questions were answered. The only real barrier at the time was generating very high laser power levels in a way that was logistically practical in the field."
- dclowd9901 3y ago“Reflective surfaces are more vulnerable”? I’m gonna need a fact check on that one.
- aimor 3y agoI suspect the issue is that the reflective materials are weak. That is, a heat shield would survive longer against a laser than a mirror.
- guhcampos 3y agoThe article is very cool and informative, I actually enjoyed it. But since I didn't know the author, it took me to the last paragraph and his signature to notice he's actually trying to sell us on the idea of putting actual Death Ray satellites in space. That's kind of cool too, but I'm sure it's a very bad idea to combine worldwide surveillance and killer lasers in space.
- asah 3y agothis was my first thought too... could they be used for assassinations? p.s. there's a joke in there for Marjorie Taylor Greene...
- JumpCrisscross 3y ago> he's actually trying to sell us on the idea of putting actual Death Ray satellites in space This is also an essential component of a planetary asteroid defence system. One could theoretically tune the power and wavelength of the beam such that it's highly destructive in space and the upper atmosphere, but mostly a nuisance on the ground.
- nradov 3y agoDoubt it. There's no way that lasers will be able to vaporize a huge asteroid. Realistic proposals for planetary defense call for intercepting asteroids very far from the planet and pushing them off course enough to barely miss us.
- lucubratory 3y agoThe point of the laser isn't to vaporise an entire asteroid. It's to push it off course enough to make it miss the Earth. The laser achieves that by pointing at a spot and turning that spot into an impromptu rocket engine.
- nradov 3y agoAn orbital laser won't have the range for that. The dispersion would be too high for any lens that we can practically launch into orbit. More realistic proposals for planetary defense call for focusing on long range detection and then using a gravity tractor or a rocket motor landed on the asteroid to slowly nudge it off course.
- loudmax 3y agoYouTuber Perun, who does videos on defense procurement, has an episode on Hypersonic missiles: https://www.youtube.com/watch?v=0n3fjoacL20 https://www.youtube.com/watch?v=0n3fjoacL20 It addresses a lot of the same topics as this Medium article.
- claytongulick 3y agoI thought a primary issue with DE weapons was water vapor? My grandfather helped design several missile systems and held patents on radar interferometry, he claimed repeatedly that laser systems would never work practically because all the enemy had to do was wait for a rainy or misty day. He claimed the power requirements for DE skyrocketed to unrealistic levels almost immediately once you had to pierce water vapor.
- sebzim4500 3y agoMost of the missiles fly above the water vapour, so that isn't really a problem for this solution.
- missedthecue 3y agoPresumably the laser system is ground based though
- sebzim4500 3y agoDid you read the article? It's mainly about giant space lasers.
- jandrese 3y agoSeems like that wouldn't be an issue for the space based lasers targeting the vehicle at the apex of its flight.
- georgeg23 3y agoAt the end he says directed energy lasers in space are the answer. But considering the ceramic thermal shielding these hypersonic maneuverable vehicles need and have, it would seem the reentry plasma is far hotter than anything a laser can add from thousands of km away. I also chuckled seeing his picture doing the interception over the water, because yes lasers keep going and you're going to be frying things on the ground too. The author is with ULA, and is competing with Elon Musk's Starshield-- which if you read the various leaks (see Michael D. Griffin) it's pretty clear will be some sort of Brilliant Pebbles system. Biden has been snubbing Elon on this. I suspect it's one reason he has turned starkly political and we are now seeing Reagan Republicans announce there candidacy on Twitter.
- sebzim4500 3y agoI was under the impression that Starshield was just a more secure version of Starlink. Do you have source that it is supposed to be a weapons platform?
- m0untaineer 3y agoIs this article germane to aircraft carrier vulnerability? What is the state of play on defending surface ships to unpredictably positioned missiles?
- troyvit 3y agoThey _are_ misunderstood. I mean you can't even hear what they're saying until they've hit you.
- jackdh 3y agoThis reads as though these are already deployed. If that is so, why have we not seen them being used in Ukraine? Surely the ground based, city defenses lasers he mentioned would be invaluable there?
- jandrese 3y agoAs far as I know none of them have been deployed to Ukraine. They probably require specialized personnel to run so even if they did want to send them there the Ukraine government would have to send specialists off to training first. Plus, it seems like the Patriots are working better than expected, even shooting down "hypersonic" missiles, much to the embarrassment of the Russian military. I think this article has somewhat fallen into the imagined capabilities trap that US arms manufacturers were constantly in during the Cold War. They would see Soviet propaganda about their new invincible weapons system and do some math on what it would take to make it work and then try to design systems to counter that paper exercise. Then they get a sample of the real thing and it turns out the Soviets were outright lying about the capabilities and the counter they developed is ridiculous overkill.
- golergka 3y agoBecause Russia is not firing ICBMs with megaton warheads at Kyiv yet.
- chrisco255 3y agoWell you wouldn't want to wait until that moment though, to deploy them.
- local_crmdgeon 3y agoWe're giving Ukraine the old stuff. You keep the new stuff for yourself, if the old stuff turns out to not be good enough.
- isk517 3y agoYou forgot the step where you use what you learned from the old stuff failing to develop even newer stuff, then hopefully you can give away the new old stuff and start the cycle again.
- jupp0r 3y ago"U.S. has excellent defenses against all classes of ballistic missiles" This is the first time I've actually read somebody making that claim. Every other take on this topic has been that defenses against long range missiles are woefully inadequate and easily saturated by a low two digit number of missiles with MIRVs.
- Manuel_D 3y agoThis is probably better interpreted as "the US has the best defenses against ballistic missiles". The Patriot missile is proven to defeat Scud missiles in real combat, and THAAD is the most thoroughly tested system against long range ballistic missiles. Is that going to stop 5,000 ICBMs with penetration aids launched against the US? Almost certainly not, and I don't think the author meant it that way.
- jupp0r 3y agoI see. We do have good systems, but too few to be of practical relevance in most threat situations. The North Korea case shows that the step from having one missile to having 100 is extremely short compared to going from having no missiles to having one missile.
- JumpCrisscross 3y ago> We do have good systems, but too few to be of practical relevance in most threat situations We somewhat intentionally lack defences against MAD salvos. Our defenses will likely remain adequate for defending against the likes of Pyongyang.
- perihelions 3y agoI don't think that's a consensus view? Jeffrey Lewis says the opposite, - "The point is that North Korea is clearly aimed at overwhelming the US missile defense system in Alaska... At that cost, I am pretty sure North Korea can add warheads faster than we can add interceptors." https://twitter.com/ArmsControlWonk/status/1315005031075123202 https://twitter.com/ArmsControlWonk/status/13150050310751232...
- LatteLazy 3y agoHypersonic is a poorly defined term. Some people use it to simply mean "faster than about 5x the speed of sound". That is what people mean when they say "China and Russia have Hypersonic missiles". But speed at that level is basically irrelevant for interception etc. Other people use Hypersonic to mean able to manoeuvre at those speeds. A normal ICBM, especially the old ones, cannot do that. They follow a simple, predictable, course to their targets. In theory that makes it easier to hit them. Only no one can do that. People have done a respectable job of shooting down non-ICBMs. But ICBMs are 10-100 times faster, further away, higher, etc. And no one will use 1, they will use 1000 and it is dooms day unless you intercept 990 of those. So all of this is really just a mix of honest ignorance (and confusing terms) and dishonest sensationalism... The point of a hypersonic missile is to NOT follow a simple parabolic curve to the target. That is what hypersonic really means: able to manoeuvre at speeds about the speed of sound. That makes it harder to intercept. Only no one can intercept an ICBM anyway. Interestingly this is why the first Hypersonic missile was actually build in the 1930s...
- ambicapter 3y ago> People thought that mirrored surfaces might just reflect the beam. It turned out that reflective surfaces are actually more vulnerable. Does anyone know why this is the case? Do mirrored surfaces trigger some sort of internal reflection which ends up absorbing more energy?
- barbegal 3y agoThis sounds like completely made up rubbish to me. Reflective surfaces definitely absorb less heat. Mirrors may however be impractical and may not reflect enough to make the missile immune.
- logophobia 3y agoOr have a lower melting point, making it more practical to use some sort of heat-resistant armoring? Might be pretty difficult to make something that both reflects light and is heat-resistant, no mirror reflects everything.
- Panzer04 3y agoI think the usual issue is a mirrored surface is not robust enough to absorb extreme levels of energy for very long before it becomes a poor mirror. I expect the counter will be more along the lines of having sufficient ablating material to block the laser - a small amount of extra armour probably has an outsize affect on survivability.
- gateorade 3y agoJust spitballing here but it might have to do with the fact that materials that absorb light are more heat conductive than materials that are reflective. The SR71 was famously painted black as a mitigation for surface heating issues because the black paint conducted heat away from the areas the were really susceptible to ram-heating. Perhaps reflective surfaces reflect some percentage of the incoming energy away, but thermally conductive surfaces conduct a larger percentage of that energy away and are able to safely sink it into some thermal mass.
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- dist-epoch 3y ago> However, the only practical way to defend against long-range hypersonic gliders, which can threaten entire regions along a single flight corridor, is from Space. Orbiting DE platforms, looking down on entire regions from the ultimate high ground can leverage “birth to death” tracking of any given glider, combined with its speed of light “interceptor,” to completely nullify this threat. But wouldn't an attacker then first take out the DE satellite, and only after launch the missile?
- TrackerFF 3y agoThat could certainly be a defense strategy, but taking down satellites work very much in the same way as taking down a ballistic missile - and there's considerable collateral damage due to the amount of space debris (which could very well induce more debris), which in turn could damage your own satellites.
- dirtyid 3y agoTrading multiple interceptors too expensive/infeasible long term against peer adversaires, magazine depth favours offense. Against peer adversaires with increasing long range precision stike, CONUS survivability against conventional attacks will eventually be an issue and the underpinning of US expeditionary model depends on ability to power project with CONUS impunity even against peers. Once that balance is upset US has to contend with homeland escalation like her adversaries.
- jmyeet 3y ago> By the way, the U.S. has excellent defenses against all classes of ballistic missiles I am highly skeptical of this claim. The author is otherwise correct: you can almost pinpoint the target soon after launch of a ballistic missile because of the way trajectories work. Ballistic missles go through three phases: launch, flight and re-entry. Modern ICBMs have a re-entry velocity as high as 7km/s (Mach ~20). Intercepts at that speed have, to my knowledge, an extremely poor record. Another factor is that ICBMs can (and do) carry multiple warheads. These will separate at different points in the flight phase or re-entry phase to hit different targets. Detecting multiple warheads isn't necessarily easy either because they're unlikely to have the visible plume of a full-blown rocket engine and it's at such a distance that radar signature probably isn't sufficient to detect the warhead let alone plot the target sufficiently accurately for a kill vehicle to hit it. The author is otherwise correct in that the real advantage of hypersonic missiles is targeting. The speed (Mach 5-10) makes intercept difficult and you won't know the target until it hits it really so good luck intercepting that. Maybe top secret THAAD development has improved to the point where it can reliabily intercept ICBM warheads at scale but I'll believe it when I see it. Most ICBM defense relies on hitting the launch vehicle in the boost phase because that's when it's the slowest.
- empressplay 3y agoI imagine the targets can be predicted based on the trajectory of the missile, the same calculations used by the missile to release the warheads could in theory be used by the defender to predict their release and intercept them.
- cwkoss 3y ago> People thought that mirrored surfaces might just reflect the beam. It turned out that reflective surfaces are actually more vulnerable. Why is this? Definitely counterintuitive.
- metal_am 3y agoJust because something is reflective in the visible light spectrum doesn't mean it's as reflective in other spectrums, say near-IR.
- partiallypro 3y agoThis is one of the more annoying things when talking to Russophiles that believe that Russia has a huge upper hand on hypersonic missile technology. What Russia is currently fielding is basically an air dropped ballistic missile. They don't have hypersonic gliding and they can't do avoidance maneuvers; they travel hypersonic...but so does every ballistic missile. They travel in an arc before reaching their target which is how the Patriot defense system has been able to intercept them. By the US goal for such technology, Russia's does not meet the criteria where we'd call designate it differently than a ballistic missile with a lower glide path and maneuvering to avoid defenses. I do think that some of the Russian upper echelon actually believed what they were touting, but in a military environment where being a "yes man" serves you better (both for your career and possibly to avoid jail/punishment), you often exaggerate capabilities to get ahead, or just lie about current status which we're seeing play out in Ukraine. The US also just avoided such tech in the past because it's so expensive, and stealth has just been better. That might change soon, but overwhelming with hundreds of missiles (and decoys) is currently much cheaper and more effective than using what the US would actually define as a "hypersonic missile." You could fire 50-100 missiles for the price of one true "hypersonic" one, and what if that missile fails? You just wasted $80M-$100M for nothing. Meanwhile a cruise/normal missile costs $1.5-5M. The US will eventually have them in their arsenal, but they will mostly never be used.
- greiskul 3y agoAnything that endangers mutually assured destruction does not make war less likely, but instead more likely. Also, militarizing space risks making Earths orbit unusable, since when you have a death laser satellite, that is a valid military target, and it's destruction might cause a chain reaction of debris hitting other satellites.
- killjoywashere 3y agoGreat article, and great commentary: "penetration aid" is a new one.
- fuoqi 3y agoIt's hard to take his praise for laser interception of hypersonic weapons seriously. For intercepting swarms of cheap drones? It's a great fit! Space-based lasers for intercepting ICBMs? Maybe? But true hypersonic weapons (which Kinzhal is not) fly only in air (after all, they use oxygen in it to fly), while being covered in a plasma shield which is really good at absorbing all kinds of electromagnetic radiation. Meanwhile, with high enough laser power you get instabilities in air which act as a natural diverging lens for your beam, drastically reducing effective range of your system. Push power even further to compensate for it and you will get plasma, which does even better job at dispersing energy of your beam. So in the end, you get a very short range interception system with a minuscule time frame to perform interception of a hypersonic target.
- Gatsky 3y agoThis reference [1] tends to support what you are saying: > For this thesis, an atmospheric propagation code named ANCHOR (Atmospheric NPS Code for High Energy Laser Optical pRopagation) was developed and utilized to study the propagation of high energy lasers in various atmospheric conditions and for numerous laser configurations. The ANCHOR code accesses existing industry databases to obtain relevant optical properties for various atmospheres and then uses scaling laws to simulate laser propagation through the defined environments. ANCHOR accounts for the effects of atmospheric diffraction, turbulence, platform jitter and thermal blooming on the laser beam, and outputs on-target irradiance and power-in-the-bucket profiles for a wide range of laser wavelengths. Several known physical trends associated with laser propagation will be reproduced, and the results will be compared to the industry accepted propagation code Wavetrain. The results of ANCHOR studies will indicate that the 100 kW-class high energy laser can effectively engage slow-moving targets at ranges greater than five kilometers in clear weather by delivering enough energy to melt 0.1 liters of one millimeter-thick aluminum aircraft skin in five seconds. For hazy, turbulent, and rainy conditions, the laser can effectively engage targets from ranges closer than three kilometers, but reasonable dwell times are only achieved for ranges closer than two kilometers. [1] https://core.ac.uk/download/pdf/36734846.pdf https://core.ac.uk/download/pdf/36734846.pdf
- Sakos 3y ago
- cperciva 3y agoOnce a line of sight is established from the DE platform to the warhead, it is impossible to outrun this “speed of light interceptor.” No high G maneuver will work. The speed of light isn't infinite. Between a satellite seeing the latest maneuver, sending data to a ground station, and a laser burst reaching its target, you've got at least 20 ms and quite likely as much as 100 ms. For a 1 G maneuver that's still going to get you within 10 cm of your target, which is just fine; but a 10 G maneuver could make you miss entirely. A larger advantage of lasers is probably the opportunity for multiple shots: If you miss with a kinetic interceptor, it's too late to launch another, but if your laser misses you'll know in a matter of seconds and you can try again as soon as your capacitors are recharged.
- gilbetron 3y agoHow do you know you're being shot at to know you should move out of the way?
- cperciva 3y agoYou probably know when in the flight you should expect to be a target based on the locations of laser batteries -- given atmospheric absorption and dispersion they're going to have limited range. Worst case, make your entire flight path unpredictable.
- personjerry 3y agoHeat sensor I would guess
- gooseyman 3y agoI had heard that space based stuff was “illegal” - finally looked up what treaty defines that “Development of orbital weaponry was largely halted after the entry into force of the Outer Space Treaty and the SALT II treaty. These agreements prohibit weapons of mass destruction from being placed in space. As other weapons exist, notably those using kinetic bombardment, that would not violate these treaties, some private groups and government officials have proposed a Space Preservation Treaty which would ban the placement of any weaponry in outer space.” https://en.m.wikipedia.org/wiki/Space_weapon https://en.m.wikipedia.org/wiki/Space_weapon
- 4gotunameagain 3y agoThe sad state of affairs is that international space treaties are practically unenforceable.. Hence ULA CEO proposing giant space lasers™ which obviously will not be defense only in the long run. The same way the US "defense industry" has never defended. And who is going to stop the Chinese from putting weapons into orbit? Heck they might've done it already and we'd be none the wiser.
- Faark 3y agoSo only WMDs are prohibited? :( A laser being able to destroy a low flying high speed missile hardend against those is probably also able to a lot more. Like destroy enemy planes. Or combatants. Or heads of states. Or pesky journalists/dissidents. Allowing sth like this to be deployed, not sure if this can be allowed by eg other nation states. It certainly puts the status quo in disarray...
- jillesvangurp 3y agoThe other thing to understand is that most of these weapons are costly and war is a game of outlasting the enemy and running down their resources. Having expensive missiles is more effective as a threat than as a means of wearing down an enemy. The threat is very simple: I can hit any target you care about and there's nothing you can do about it. The flip side is that you only have a limited amount of these missiles and once they run out, the threat goes away. So the trick is to use enough of them to make the threat credible but keep around the remaining rockets to keep the threat credible to minimize loss of resources. That makes them more effective as a defensive weapon than as an offensive weapon. A lot of modern wars are asymmetric where a technically advanced party with superior resources is worn down by a relatively unsophisticated enemy over time. Consider for example the British, Russian and US attempts to conquer Afghanistan. They each failed. The fallacy here is that committing a lot of resources is expensive and not long term sustainable economically. Once the will to continue fighting evaporates, you basically lose the fight. All the other side has to do is keep on fighting.
- fennecfoxy 3y agoLasers are a cool solution. I wonder if it's possible to reduce scattering using a fore-shot before the main pulse, surely the fore-shot would mostly clear a column through the atmosphere by the heating of any particles in the path of the laser. I don't really know the physics of it but it seems like something like that would work. Would be cool if we get to the point where we can ionise a very narrow column of air and then use it to deliver an electrical arc as directed artificial lightning! A la Loki's LIP-C: "Brian Gragg kicked his chair away and stood up from the gaming workstation. As the blinded strike team members writhed on the floor, crying out, Gragg moved calmly toward the burly team leader who had shouted at him. Gragg aimed a silver-capped index finger at the man—a lens at its very tip. Black fiber optic and electrical cables ran down the back of Gragg’s hand like veins, disappearing beneath his shirt. “The name is Loki, asshole.” A ruler-straight bolt of electricity cracked like a bullwhip from his fingertip into the man’s body armor, followed by a flickering series of bolts in quick succession—three a second. The team leader’s muscles jerked with each thunderclap. The smell of ozone filled the air." (Daniel Suarez)