U.S. Air Force has shot down multiple air-launched missiles in a test
thedrive.com
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It's just a light bean albeit concentrated one, how hard can it be to deflect it?
Edit: don't understand the downvoting, please enlighten. Your wisdom is not obvious to me. Thanks
Mirrors don't perfectly reflect light in all frequencies. Mirrors are designed to reflect mostly visible light, lasers at this power level are infrared. Any imperfections in the reflective surface would immediately heat up, damaging the reflective surface, which would then heat up even more. And even if it were perfect, and were designed to reflect whatever frequency of radiation the laser's putting out, it's still not going to reflect 100% of the laser's output, and you've probably got yourself a material that's pretty impractical for a rocket.
[1]: https://phys.org/news/2018-03-air-fighter-mounted-laser-summ...
[2]: https://newatlas.com/lockheed-martin-laser-truck/36377/
What is probably way easier though (and actually survives launch and particles hitting it and is already proven in practice) is to use ablative heat shields on missiles. The materials available are already optimized for mass vs. effectiveness due to the engineering constraints in space flight. Missile optics would probably need to be coated though or distributed.
[1] https://www.osapublishing.org/ol/abstract.cfm?uri=ol-23-20-1... [2] http://ab-initio.mit.edu/book/
The word "ablative" is typically used in reference to reentry. As the vehicle encounters incredible heat as it comes back into the atmosphere (due to compression heating or whatever), the shield intentionally has some part of its surface gradually boil off.
Let me get what you're saying straight. Superpower A would launch an ICBM, and then Superpower B would then laser it as it flies through the air or space. As the missile absorbs the laser heat, its surface starts to boil off, but if the laser doesn't boil off enough, then the laser counter-attack on the missile could still be survivable.
</armchair-general>
Edit: I didn't think of space but in space this could even be more viable since the ejecta from the ablative heat shield will just stay with a body in free fall and further scatter incoming radiation at least a little.
I rather thought about shorter engagements where a missile only takes tens of seconds and needs to be destroyed quickly. Each second an ablative shield buys improves the chances of a hit.
Also used when nominative, dative, accusative, genitive and vocative heat shields just won’t do the trick.
But more importantly I'm not sure how you can have one and still have a missile guidance system on board, and also they tend to be pretty heavy.
AVCOAT 5026-39 which apparently is an ablative heat-shield material for NASA's Orion (and has been developed during the Apollo years) has a density of 0.51g/cm³ so about half the density of water and one fifth that of aluminum (of which a guided missile is made mostly, I believe).
From reading some reports of the performance of Apollo era heat shields it's clear though that reentry is a way more gentle affair in terms of thermal load, than a 50kW laser in a 1cm2 spot.
The endured peak heat flux per area is about 0,48 kW/cm2 for the heat shield, magnitudes off, if the 50kW laser can achieve a 1cm2 spot.
The total amount of heat flux the ablator was required to endure results in a total amount of heat energy/area of 0,0141 kWh/cm2 - which 50kW in a 1cm2 spot would saturate in about 1 second. Reentry lasted 800-1000 seconds.
In that context rotating reflective missiles make this much harder as does slightly thicker casings. Anything you deploy optimized for today’s missiles is easy to design around, so you need to design for countermeasures.
My point is if you find the minimum power output to be X kw, you want to deploy something at ~4x power output to deal with fairly easy modifications.
PS: Stealth capabilities is probably a bigger long term issue, but that’s a large modification.
The 50kW laser that the air force wants is a sustained laser. This is not at all comparable to the petawatt lasers used by scientists, which produce pulses on the order of a femtosecond. Such a brief pulse would not be able to destroy a missile since the total amount of energy delivered is very low.
So yeah, pulsed lasers can do it, and I'm certain the Air Force would rather be using them. They are finnicky though.
Not for petawatt lasers, those are around 1Hz or lower [1].
Do you really think they are so incompetent so as not to have thought of this?
I’m sure the labs developing these are aware of what you’re suggesting, have probably even tried them, and have their reasons for the design they’ve chosen.
They likely want to used pulsed lasers assuming average power output stayed the same, but physics is a bitch. So, they don’t get to arbitrarily chose.
We already have pulsed lasers with average power output in the kw range over several hours. Even better, this thing does not need to fire for hours at a time so you can skimp on heat dissipation. But, you can buy 2kw laser cutters off the shelf.
Really, scaling it up in a lab is one thing, but getting everything else to work like dealing with vibration, portability, and targeting is hard. So, while this design had slightly better tradeoffs, that does not say much about the design space they where working with or what they consider useful vs required. Ex: What frequency is this?
That said, I would be shocked if they can dissipate enough heat to fire a continuous beam for an hour. It’s very likely designed to be pulsed over longer time periods.
I suspect the flow of air around the missile provides effective cooling.
I mean, I get it .. I'm no physicist and have no idea how any of this works ..
Painting the missile black makes it so that it absorbs energy more efficiently. Making the laser more effective. This is why people are suggesting mirrors as mirrors reflect energy away without absorbing it, but other people have comments about why that won’t work perfectly.
Think of wearing a white vs black T-shirt on a sunny day. Which shirt is hotter? From my experience it’s the black one since it absorbs all the sunlight and heats up; whereas, the white shirt reflects a large amount of it and heats up less.
So even if we take the 99.9% one, your 50kW laser will only heat it with 50W of power, which is nothing compared to the heating an ICMB (or its warhead) has to withstand.
It is a very interesting idea, the reflectors likely will burn but you could cover the missile with them. You only need to reflect enough to disable/weaken the emitter.
High quality mirror material with > 99.8% reflectivity near infrared region would do the job. Multi layer metal substrate, usually copper based or fused silica to withstand thermal expansion and dielectric coating. High macroscopic surface quality is not needed. It's enough that it reflects.
Even the mirrors used in laser erode. Laser weapon uses larger mirror area to focus tighter beam to the target. But unlike laser mirror missile surface don't have to withstand erosion long time and you can rotate the missile to divide the thermal power to larger area.
There are practical reasons why the best practical option is not mirror but material with high thermal resistance. Hypersonic missiles already use those materials and they are protected against current generation of military lasers (50 to few 100s of kilowatts). You need megawatt lasers if you try shooting down HGV.
From the descriptions that gramps used to give me, I'm not sure how what's described here is an advance over what he did back in the late 70s. I guess one thing is that back then, they were nowhere near being able to put the whole assembly into a pod that could be mounted on a fighter jet's wing.
(gramps also worked on the Hubble Telescope, and spy satellites)
[1] Am I getting old or is it weird realizing that 1970 was almost 50 years ago?
Aircraft these days have much better electrical power systems (since all control surfaces and a lot more engine operation is electrically powered), and new aircraft carriers and surface combatants are being designed with about 50-100% margin on electrical power to make them compatible with these systems in the future.
The question itself was fine and got interesting answers. Phrased differently, I don't think anyone would have downvoted you.
You’re doing that ‘I am very smart and have found an obvious flaw sitting here that none of the professional missile engineers thought of’ thing. Makes a lot of people cringe.
Once the missiles are launched, you need to navigate them actively towards the target at roughly the same flight profile as a real missle, otherwise why would the enemy bother engaging them? So they need guidance, which adds more cost and weight.
In the end, you'll end up with a "decoy" that has everything the real missile has except for a warhead, so why not just put a warhead on it?
At that point we're talking about just building more missiles, period.
Joking aside, if they can get this into a compact form that can be adequately supplied and cooled, it'll be a quantum leap in weaponry. You're talking about going from hurling chunks of matter that in turn impart kinetic and thermal energy, to being able to project energy directly.
It is both amazing and slightly terrifying... Imagine when this weapon can be hand carried by an individual soldier. Or even a crew served weapon like a 'Ma Deuce".
Scimitar link: https://en.m.wikipedia.org/wiki/FV107_Scimitar
B. Every so often the military hits the reset button on nomenclature. For example, the B-1 was not the first bomber ever built.
Lets assume the laser works by dumping a lot of thermal energy into the missile. It's safe to assume for two reasons - primarily because I think that the power requirements for anything other than that would be ridiculous, and because they specifically talked about 'destroying' the missiles in question, rather than simply burning out the sensor package. Also...that's pretty much how laser/directed energy weapons work - you dump energy into a point until it catches fire.
People are mostly water (citation needed). Missiles are mostly meta (ibid)l. Water takes a lot of energy to heat up, while metal heats up quite easily - we know this because we know that a Calorie {kilo-calorie for those at home} is the amount of energy needed to raise 1 kilogram of water 1 degree C, and is equal to ~4500 joules. To do the same thing to copper and steel, you need something like 350 and 500 joules, respectively (this is a property called specific heat, and is really cool and I wish I wasn't bad at thermo so I could talk about it more accurately).
Anyway, it takes a very large amount of energy to hurt a person, and a smaller amount to destroy a missile. There are two ways of getting that energy out of a laser - in one big ass pulse, or in a longer stream. Looking at the mount, and the platform the laser is to be deployed on, I believe this works with a 'stream' of energy. Fighter jets are not power plants (citation needed) and have a lot of high powered electrical equipment on them already (radar(s), communications devices, whatever sensor packages they have, flight avionics, cooling, and the computer(s) that co-ordinate all this). You don't want your displays going dark because you're charging the laser. Additionally, high energy pulses tend to be destructive to their components. Having only one anti missile shot before you have to under go maintenance to replaced a bunch of fused emitters and whatnot doesn't' seem like the best idea. With a lower energy continuous beam, you don't have that destructive flow, and while the total power draw is probably similar to a pulse, you're pulling that over a longer period, which is much easier to plan for.
Pulling it all together - the laser's target has different thermal properties than a human does, and probably takes a few seconds 'on target' to work. Depending on how long you stayed in the beam, I'd expect anything from first to second degree burns, probably from the water in your cells turning to steam and bursting, but nothing catastrophically bad unless you were lasered continuously the entire time, and even then I don't think it would kill you, just burn you quite badly.
Unless you looked into it. That would probably go poorly for everyone.
It would also be much faster than their current interceptors.
I just wonder how well it would work against low-tech targets.
Israel is pursuing its own high-energy laser defense program, Iron Beam (yes, not so creative). From public sources, it's not clear if the thing is 1-2 years from deployment, or if it's in development hell; the US is uniquely public about these high-budget prestige projects for internal political reasons.
Clearly should have been called God Ray or Finger of God.
Naming your weapons after religious artifacts reminds of Monty Python's holy hand grenade. Probably not a great idea to connect your religion to something that explodes and kills people.
Merkava is their main battle tank.
I don't know if there's prestige in being 7 years late to the party.
Rheinmetall demonstrated this tech in 2012.
Rheinmetall didn't demonstrate what you're implying. You're conflating two entirely different systems.
The US has so many laser programs that predate the Rheinmetall example, it's hard to decide where to start. HELLADS, AN/SEQ-3, Boeing YAL-1, HEL-MD, THEL, MLD, etc.
Like this one:
"On March 18, 2009 Northrop Grumman announced that its engineers in Redondo Beach had successfully built and tested an electric laser capable of producing a 100-kilowatt ray of light, powerful enough to destroy cruise missiles, artillery, rockets and mortar rounds."
Or:
Precursor to the Boeing YAL-1: "The Airborne Laser Laboratory was a less-powerful prototype installed in a Boeing NKC-135A. It shot down several missiles in tests conducted in the 1980s"
THEL:
"The Tactical High-Energy Laser, or THEL, was a laser developed for military use, also known as the Nautilus laser system. The mobile version is the Mobile Tactical High-Energy Laser, or MTHEL. In 1996, the United States and Israel entered into an agreement to produce a cooperative THEL called the Demonstrator, which would utilize deuterium fluoride chemical laser technologies. In 2000 and 2001 THEL shot down 28 Katyusha artillery rockets and five artillery shells. On November 4, 2002, THEL shot down an incoming artillery shell. The prototype weapon was roughly the size of six city buses, made up of modules that held a command center, radar and a telescope for tracking targets, the chemical laser itself, fuel and reagent tanks, and a rotating mirror to reflect its beam toward speeding targets. It was discontinued in 2005"
So to intercept 20 missiles you'll need 20 expensive "turrets", your enemy knows how many "turrets" you have and can easily flood it with more cheap missiles.
Also remember that target destruction is not instantaneous, this limits the amount of targets per "turret" and the minimum range.
That was Soviet Frontal Aviation's strategy for dealing with carrier battle groups as far back as the 60s. It's certainly in the DOD's considerations, and it isn't as easy as it sounds. For starters, you need to let the firing platform get within range to being with.
In rain, common LIDAR wavelengths, like 905nm and 1550nm lose about 0.1-1% of their power due to scattering per meter travelled and on top of that 0.1-1% due to absorption. Of course, this will not scale linearly with higher power but it's a lot even if it's ten times less.
For laser weapons to be effective you need a clear line of sight in the respective wavelength.
I feel like Val Kilmer is about to make an epic bowl of popcorn with this thing.
Is this true for a laser mounted on an airplane? How is the energy stored?
Presumably as jet fuel, and the laser is charged by the plane's engines.
1. https://en.m.wikipedia.org/wiki/AN/SEQ-3_Laser_Weapon_System
[1] there's no direct conversion as it depends on speed, but 266000 HP = 198 MegaWatt figure for a slow-flying Boeing 747 gives rough idea, as per https://www.quora.com/How-many-horsepower-is-a-Boeing-747-Je...
[2] some fighters and most larger planes are also equipped with an independent APU - a self-contained power generator, also feeding off of the jet fuel
The RVs themselves are small, hardened and move incredibly quickly and are also surrounded by a plasma shield during reentry which may interfere with targetting with a directed energy weapon.
It kept the peace for 50+ years. (Excluding all the "little" wars.)
that out of the way, it is regimes that don't show a real concern for their people that is the danger. the only hold on them is the vulnerability of those making the decision. once they show disregard for their own welfare is when everyone should be worried.
I doubt that these exist, "look, these people are crazy and suicidal and don't even care about their own children" is a common propaganda statement, with the clear purpose of de-humanising the enemy. Even the most ferocious dictators care about some of the people, and about their own cultural heritage, and the country they rule. Nobody wants to be wiped off the face of the earth.
An inbound air-to-air missile is a very tricky target. It is face-on. Your laser cannot target the explosive bits of the missile (the rocket motor that is active for the first few seconds of flight). But that doesn't matter. "Shooting down" can mean jamming the missile's IR sensor or damaging its radar dome, both of which would stop it as a threat. The real problem imho is the size of the emitting aperture. Focusing a laser tightly at any distance requires a device probably too large for a fighter aircraft.
Shooting down a missile from the side, from the ground or form an escort aircraft is another matter. Get it during the boost phase (the first few seconds after launch) and even a pinprick through the side of the rocket motor will cause it to explode. But in that scenario why wait for the missile to be launched? If you can burn through the rocket motor after launch, you can do so before launch. My point: any weapon capable of explosively shooting down misses in flight is also capable of shooting down the launching aircraft before it gets a chance to fire.
Oh, and don't forget that such weapons are probably illegal under various treaties. If it can shoot down a missile a one mile it can blind a pilot at ten. Pointed at the ground it could blind scores of troops. Some legal hoops would need to be jumped before one could ever deploy such a laser.
Focusing a laser onto a 100mm point at 5km does not seem like it would take that large of an aperture, and that should be all you need to kill the seeker.
> Get it during the boost phase (the first few seconds after launch) and even a pinprick through the side of the rocket motor will cause it to explode in a true "shoot down".
IIRC most air to air missiles have a boost phase far longer than that - I think most will still be burning at intercept for shots inside the killbox. That's part of the selling point of the Meteor [0] - it can throttle, so it'll almost always be burning at intercept.
> But in that scenario why wait for the missile to be launched? If you can burn through the rocket motor after launch, you can do so before launch.
It's a lot easier to argue that the other side shot first when you blow up the missile AFTER it leaves their plane. Not to mention the case where the responsible aircraft wasn't detected until after launch...
It gets trickier than that. From the perspective of the target missile the laser is a pinpoint source, easily ignored/blocked. You have to hit is with enough power to actually do damage. 50KW over a 10cm seeker head won't be enough. A missile is supersonic. That seeker head is already being bombarded by plenty of IR/heat and is actively cooled. You need to focus down to far less than a centimeter to start burning things.
And I can't help but think that a pinpoint source coming from your target is harder to ignore than one coming from anywhere else.
Either way, at mach 4 it takes ~3.5 seconds to cover 5km. 50kw * 3.5s = 175kj, 42 grams of TNT equivalent. That's still a fair bit to mitigate. (but also not nearly as much as I was thinking)
However destroying magnitude-smaller, nearby air-to-air missiles is much more achievable and was demonstrated by the NKC-135 / Airborne Laser Lab project back in 1979-85. Yes, 40 years ago.
Also, I know the F-35 has the power plant to run one of these but could one be mounted on an F-22?
https://www.physicsforums.com/threads/does-a-laser-have-a-re...
Also, compared to building additional missiles, having your missile split into a bunch of decoys and a few warheads is fairly inexpensive.
See “The Protocol on Blinding Laser Weapons, Protocol IV of the 1980 Convention on Certain Conventional Weapons”
https://en.m.wikipedia.org/wiki/Protocol_on_Blinding_Laser_W...
It’s quite short and to the point. No weapons designed to permanently blind people are allowed. Incidental blindness is ok, also if you get blinded while looking through binoculars that’s fine. Blinding sensors is also fine.
Iron Dome uses ground-launched interceptor missiles, tied in to a theater-level control net, to intercept short-to-medium-range surface-to-surface ballistic missiles.
This uses a self-contained, at-some-point-aircraft-mounted laser, to shoot down guided, powered, maneuvering air-to-air or surface-to-air missiles.
When will the US have this capability? I would ball-park this at about 15 years for now.
What options does Russia have. By my cont 3 options (hardware-based; I'm not counting cyber-warfare and psychological and subversive warfare).
1. Deterrence in numbers. Currently Russia deploys 1600 warheads, and has a total of 6500 (deployed+stockpiled+retired). If they go to 20-30k warheads, in an all out war a few dozens might still find their way to some large urban areas in the US, and so even a 99.9% ABM capability might still leave a few tens of millions of Americans dead.
2. Laser-equipped anti-anti-missiles. If you can zap a nuke out of the sky, you can zap the missile carrying the laser too. Provided you have the technology. I expect Russia to have a delay in implementing this technology, maybe 5 to 10 years
3. Alternate threats that are immune to this defense. This is exactly what Russia demonstrated one year ago: a hypersonic nuclear-capable, nuclear-powered missile that can travel in the lower atmosphere (where the effective range of a laser is reduced, due to light absorption) plus a mega-nuke delivered by an autonomous submarine that purportedly can create a 500-foot tsunami that would wipe NYC from the map.
Where does that leave us? The US will enjoy the maximum military gap about 20 years from now and this will provide a huge incentive to perform a decapitation strike. Would this be palatable to the US population? Only if it can be demonstrated that the collateral damage would be insignificant. Is that possible? What do you need to do? You need to take out the missile silos, the strategic nuclear submarines, and the strategic bombers (the nuclear triad). The silos are traditionally the targets of some nukes; in the past these nukes had about one megaton yield, but with the increase in missile accuracy the current US yield is about 100kt; this is still 5 times larger than Nagasaki. Is it possible to use a smaller nuke with an increased accuracy? A rule of thumb is that a 10-fold increase in accuracy can reduce the necessary effective yield by 100. Starting this year (2019) the US Navy will have a 5-7 kt nuke in its arsenal (W76-2 [1]). This type of nuke could ensure essentially zero civilian casualties, while still being able to destroy most missile silos. Oh, and it would also be a good anti-strategic-submarine weapon too.
So, about 20 years from now, the US will have a once-in-a-century opportunity to break the mutually-assured-destruction stalemate, and potentially rid the world of nuclear weapons. All with minimal loss of life (especially civilian life). But the window of opportunity will be very short, Russia will be able to close the MAD gap in a few years. Which will make this opportunity a very difficult one to pass on.
[1] https://www.theguardian.com/world/2019/jan/28/us-nuclear-wea...
> The US will enjoy the maximum military gap about 20 years from now and this will provide a huge incentive to perform a decapitation strike. Would this be palatable to the US population? Only if it can be demonstrated that the collateral damage would be insignificant. Is that possible? What do you need to do?
A decapitation strike couldn't be debated. It would have to be done. The US population would only accept it--and only in part, as some segments would never accept it--as a fait accompli if there were zero US casualties, few foreign civilian casualties, no/minimal residual health risks, and limited reputational damage to the US. I highly doubt any, let alone all, could be accomplished with a nearly sufficient degree of confidence, even with groundbreaking missile defense systems.
The risks of miscalculation are staggering, and the immorality of attempting or even seriously considering (as a policymaker) such a "decapitation strike" in the current or foreseeable future global context is indisputable.
Quite succinct and accurate. I have to admit, reading my own words, I do sound like a crank.
So, let me give a more nuanced view. I think the probability of an all-out nuclear exchange is still quite reduced, but if the capability gap between Russia and the US extends considerably, this probability will increase from the current infinitesimal level to a non-negligible one. Other events that were once considered unthinkable (DJT, Brexit) have come to pass, so never say never.
With that said, how can we get to such an extreme event as a nuclear exchange? I think that whenever there is a military crisis in the world (Iran threatening to resume uranium enrichment ?) the POTUS asks his advisors for options. The spectrum of options ranges from PR spin machine, to diplomatic pressure, to military operations. All options will have listed their pros and cons, their best, base and worst outcomes. They will be judged in isolation and weighed against each other. After this careful comparative cost-benefit analysis, the POTUS makes the decision.
Now all things being equal, if the military gap between the US and the opponent is larger, the armed response options will comparatively have a better cost-benefit ratio. The more impenetrable the ABM defense becomes, the more the military option will look like the better deal.
Now the vicious cycle is that, as the military option is chosen more often (how long did it take DJT to send an aircraft carrier towards Iran?), the more tensions will appear, and the more crisis situations will emerge. Some of them will be de-escalated, but some will escalate to various levels. Sometimes cool heads will prevail, but sometimes the grown-ups will have left the room already. One day Russia might do something that would trigger Nato's article 5 [1], and the US will have to respond. You could say that we've been in many situations like that in the 60's, 70's and 80's, but the military gap between the US and the Soviet Union was never close to what it's now, and what will become in the coming decades.
Ok, ok, but nuclear, you say? Well, the US has dropped about 100 bombs in Nevada, just 60 miles from Las Vegas, and it was no big deal. A few (hundred) small-ish nukes going boom in the middle of Siberia will result in some condemnations from some pacifist organizations, but as long as there is some reasonable casus belli and minimal civilian collateral damage, people will move on quite soon.
[1] https://www.rferl.org/a/explainer-nato-articles-4-and-5/2462...
Is anyone actively working on laser deflector shields?
You don't have to loiter for all time.
That said, I'm thinking pumped-laser-tipped missiles could be very effective as e.g. anti-ship weapons. You could launch one straight up from your territory, and have it snipe the enemy ship from far away. The enemy would have to monitor a large portion of the sky for relatively small objects and react instantly with lasers of their own to counter that.
EDIT: I suspect these could be made into pumped-laser shells; good luck countering one that's launched from beyond the horizon.
True bolt-from-the-blue attacks are rare, though possible.
The spray profile could be modified to enable sensor detection, or alternative (off-ship, buoy, balloon, drone, ...) sensor placement could enable both eyes and shields.
More high, less ground.
https://en.wikipedia.org/wiki/Fractional_Orbital_Bombardment...
So: no.
The lasers will probably remain, and missiles will get better and better penetration aids (stealth, reflective/ablative/insulating coatings, etc) to get past the lasers.
At even higher powers, lasers may outclass missiles as anti-aircraft weapons, but we're not nearly there yet. In the surface-to-surface realm missiles are more likely to be obsoleted by railguns than lasers.
The ballistic nature of artillery, missiles, and other projectiles allows hitting targets beyond the horizon. Lasers are uni-directional so whilst they would be great against targets in line of sight, I doubt you'll see laser weapon systems employed as long range weapons for a very long time.
Of course, you could deploy them from a platform like a satellite, or aircraft, but the power requirements are immense and any current day aircraft would probably be so large as to be a sitting duck. I recall they've carried out testing of this nature using a 747 as a test platform. Until they can make planes of that size more survivable, I guess we're stuck with defensive applications.
[1] https://en.wikipedia.org/wiki/Suppression_of_Enemy_Air_Defen...
As for "laser deflector shields", we haven't cracked the "deflector shield" part yet. The closest thing we have to force fields is actual matter - in this case, probably kicking up a dense dust cloud to scatter the laser.