# Do powerful lasers mean no aircraft is safe?

The US Military is publicly preparing to deploy +100 Kilowatt laser systems on its potentially vulnerable surface ships (see linked question). Which probably means that it has secret prototypes and special service weapons that can output in excess of 1 Megawatt. These weapons are capable of blasting drones out of the sky and small ships out of the water in a matter of seconds. The reported cost per shot is somewhere in the neighborhood of $1, thousands and hundreds of thousands of times cheaper than shells or missiles. While there may or may not still be issues with bad-weather performance of these systems, there seems to be a clear upward trend in the capabilities and cost-effectiveness of laser systems, with a corresponding decrease in the system size and toxicity. Now, since the speed of light is much much higher that that of any aircraft, does if follow that extraordinarily powerful lasers will make current types of aircraft obsolete? Are aircraft essentially sitting ducks to these weapons? • The speed of a human is much less than that of a bullet, but does that mean that bullets always hit humans? The real limitation might be how fast the muzzle of the laser gun can turn. If the muzzle can move fast enough to keep up with a moving plane, computer targeting and the speed of light could probably take down the plane. – Obie 2.0 Sep 22 '15 at 0:08 • Sure, but bullets suffer from wind, gravity, unsteady hands, etc. Lasers only suffer from divergence, and the occasional atmospheric refraction. – Serban Tanasa Sep 22 '15 at 0:23 • There is that. What I was referencing is that if you see someone moving to point a gun at you, you can move out of the way. It's not bullet versus human--no one dodges bullets--it is human vs. human. People do dodge humans. – Obie 2.0 Sep 22 '15 at 0:49 • Suppose you spot a plane, some 5 km away. You are a ship; presumably the plane has already spotted you. Your laser gun is only 5 degrees from a position where it can hit the plane. Let's say your turret can make three revolutions per second. That seems reasonably fast for a massive gun. Perhaps the plane is 3 meters high. Assuming the gun aims for the center, the plane will need to travel about 1.5 meters (upward or downward) in 0.004 seconds, or about 375 meters per second. That is about 838 miles per hour. Obviously, we are assuming computer navigation. – Obie 2.0 Sep 22 '15 at 1:07 • If the gun is pointing opposite the plane, that makes the time it needs 36 times as long. So the plane only needs to move at 10 meters per second. To accelerate to 10 meters per second in 0.14 seconds requires 70 m/s^2 acceleration--although the plane needs to accelerate faster than that. That's only 7g, which pilots in fighter jets already experience in turns. On the other hand, in the previous circumstance, well, the acceleration needed could be lethal. And this is only one gun. – Obie 2.0 Sep 22 '15 at 1:14 ## 10 Answers Aircraft already have to deal with deadly weapons nearby capital ships, they already cannot enter the visual range of battlegroups. Its not like you bomb destroyers using dumb bombs a la ww2. A major factor on the development of anti-ship aircraft was the area denial weapons aboard combatant ships. We usually talk about standoff weapons while talking about antiship missiles. This laser wont change much. A SM-2 missile fired from a destroyer reaches much longer ranges than such laser and denies the air space around the carrier battle group since the nineties (or before). Those lasers will be used against anti-ship missiles, the aforementioned standoff weapons. Russians developed a plethora of supersonic antiship missiles and deliver means (subs, ships, aircraft, shore etc). Theres no real qualitative change from a phallanx/aegis combination or a laser/aegis, but a quantitative one, the laser is more effective than a chaingun at destroying incomming missiles. Russians dealt with this problem by using saturation strikes, and so, this laser, in the end of the day will make any future attacker need to allocate more missiles per battlegroup in order to ensure a high probability of killing the carrier. Besides that, this laser might be used against chinese ballistic anti-ship missiles, wich are, currently, almost impossible to deter. So far so good, this laser does not change a lot in the possible naval battles of the future. Russian missiles like sunburn/moskit fly at 3 times the speed of sound and can autonomously detect/track/engage ships in a battlegroup without human intervention. You might very well consider a sunburn missile as a kind of drone (all elements of a drone are there). In other words, all this discussion was done under the wrong assumptions. • While China claims their ballistic carrier-killers can't be beat that doesn't make it so. Desert Storm taught us that killing ballistic inbounds needs to be skin-to-skin but Israel seems to be accomplishing that with their Iron Dome system--I'm sure we've been paying attention to what they've learned. So long as the inbound doesn't contain a big nuke I would expect us to stop it. – Loren Pechtel Sep 23 '15 at 3:15 • @LorenPechtel Issue with ballistic missiles is that they can be relatively simply scaled up. A ballistic missile that can survive a hit from Phalanx or a laser is just as practical and efficient as one that doesn't, it just has to be larger. Size is an issue for Palestinians who have limited resources and need to hide and Russians who needed ship and air launched missiles. But the Chinese AFAIK mostly rely on shore based batteries where using larger missiles that are harder to stop and cause more damage on a hit is not a real issue. – Ville Niemi Sep 23 '15 at 11:52 • "Its not like you bomb destroyers using dumb bombs a la ww2" I very nearly downvoted you. During the Falklands War, the Argentines did exactly that. Every ship in the British fleet suffered direct hits. What saved them was the extreme aggressiveness of the Argentine pilots, who got too close in their attacks, which resulted in the bombs not arming before they hit. So the bombs passed completely through the hulls without detonating. – WhatRoughBeast Mar 14 '16 at 15:39 • Yeah,thanks for downvoting. Please tell me how many years had passed since malvines and today ? 30 ? – Jorge Aldo Mar 14 '16 at 18:39 • The answer is the ICBS: The Intercontinental Ballistic Spear. Its like a missile, but instead of delivering a bomb it is just a big hunk 'o metal. – Marshall Tigerus Jun 29 '16 at 15:56 # No. Even with advanced lasers, Aircraft can still be feasible, provided the designers of the aircraft build with laser defense in mind. What kind of defenses could you put on a plane that could help protect it against high powered lasers? Well, let's first take a look at how the high powered laser would destroy things. It's most likely that it would heat up target enough that it either • fries the internal components • Melts the outer layer and then the inner components • Some other sort of heat related damage All of which really boils down to just "heat damage". Depending on the strength of the laser, here are some options that could be installed on the plane to defend it. 1) Heat shields Think space style heat shields. As in space shuttles. The shielding they use on those ships are designed to soak up ridiculous amounts of heat - by putting that stuff on our planes, assuming sufficient plating and possibly a new method of propulsion to help with the weight increase, it is possible for the planes to survive the lasers since the shield will simply absorb the heat. Graphene plates might also work for this, since those tend to absorb heat very well, Ceramics being a third possible option. 2) Rotating armor Heat lasers have a big flaw over all - it needs time to heat up the target. So all we need to do is make it so that the laser cannot stay on the same area long enough to heat up the target. Thus, I propose "rotating armor". By having armor plates that shifts around all the time in random motions (probably machine controlled), the laser will constantly be targeting a "cool" area that it needs to heat up, but by the time it even gets slightly hotter, that area has moved away and the laser is now targeting a new spot on the plane. Meanwhile, the previously targeted area is cooling down. 3) Ablative armor Ablative gel/armor can be used "short term" to protect your plane while it quickly flies to the target to blow it up. Although this basically is just a different type of heat shield, I thought it different enough to give it its own number. :P 4) Shrouds The laser needs to be able to target the plane in order to hit it. So all we need to do is stop the targeting. Before flying your plane into the defended area, fire "shroud missiles" mixed with actual missiles into the area. Let the enemy's lasers take out all the missiles (because if they don't take out all of them, a real one might be allowed to land). As the shroud missiles are destroyed, they should spread some sort of dense cloud of material over the area, and assuming you shot enough of them (or the clouds of X are large enough), just fly over the material and use the material as a shroud between the plane and the lasers. Since the lasers are (probably) stationary, you can just drop bombs (or large rocks kinetic projectiles) on where you think they should be to disable them. 5) Mirrors How about just a mirror coating? Assuming energy density damage threshold in common dielectric coatings is$\approx 14 \;\frac{\text{J}}{\text{cm^{2}}}$for a$20\;\text{ps}$pulse (According to this site), and assuming that the laser is a continuous wave laser, it would have a power density of$7 \cdot 10^{11} \;\frac{\text{W}}{\;\text{cm}^{2}}$. (Power / Area = Power Density) Assuming a$\approx 10 \;\text{cm}^{2}$area for the focal point (at long distances), you'd get$10^{4}\;\frac{\text{W}}{\;\text{cm}^{2}}\$, meaning that the mirror coating would indeed protect the plane against such a laser.

6) (This one is just speculation, I have no idea if it would work and it's just an idea I had) Prisms

Assuming that in the future, we can manufacture prisms that don't break under high powered lasers, you can cover your plane in a layer of prisms. The idea is to "bend" the laser away from the body of the plane using that layer of prisms. Since the prisms don't move relative to the plane, assuming it was placed properly the plane should be completely impervious to lasers as the lasers would just bend around the plane and never hit it.

But then again, you could just use a really big prism as a frontal shield when flying towards laser protected areas... Just make sure you blow up the lasers before leaving ;) .

• It should be noted that most of those countermeasures fill fail with the advent of higher powered 'pulse lasers'. Current devices do indeed cause damage through heating, but one powerful enough to cause ablative shock will be impossible to armour against, for the same reasons as aircraft are not armoured against kinetic weapons - it is too heavy. – moran Sep 22 '15 at 5:25
• @moran Planes aren't armored atm because our engines aren't efficient enough to allow heavier loads. In theory, with the invention of better propulsion systems in the future, heavier loads will be possible while maintaining high speed, allowing for armor to defend against both kinetic and heat based weaponry. – Aify Sep 22 '15 at 6:59
• (not-so) New lasers are cutting through 20 feet of steel in a second. – user3082 Sep 22 '15 at 17:37
• @user3082 At what range? What's the size of the focal point? A second is a very long time to stay focused on a single point on a target that's moving very fast, especially if it moves in erratically and implements some of the defences I've detailed above. – Aify Sep 22 '15 at 17:46
• @Aify I think that we are pretty close to the max for chemical fuelled turbine performance now, although scramjets etc offer alternatives. Problem is that the faster you go the harder it is to turn which is the effect more mass(armour) also has, although the latter can be counteracted by better thrust-to-weight to some extent. Also, as you go faster, and as your engines become more powerful, stealth is less likely. All of which makes it easier for the laser to target. – moran Sep 23 '15 at 10:14

It does not follow that lasers will end aircraft as we know them. Lasers work by inducing heat in a target which can't be attenuated quickly enough to prevent damage. If this heat can be reflected, ablated or avoided all together then a beam weapon is useless.

Reflection

This is perhaps the easiest route. Developing highly reflective coatings effective against IR, visible and the longer end of UV is a common thing. An aircraft will still need conventional camouflage so these highly-reflective coatings will need to be underneath normal paint.

At the bare minimum, an IR reflective coating will need to be added to all windscreens and cockpit canopies. Even if the aircraft may survive a laser strike, the fragile retinas of the pilot may not. A blind pilot is a dead pilot.

Ablated

An ablative layer could be added to the underside of the aicraft. This carries a weight penalty and may interfere with any stealthy coatings on the plane. Space shuttle style tiles or coatings may help by absorbing the heat of a strike.

Avoided

Combat aircraft already have countermeasure systems for detecting and defeating radar guided and IR missiles. Laser detection systems could also be developed and deployed to aircraft. When the laser detection system triggers, an evasion autopilot may take control to jink the aircraft in unpredictable patterns and get out of the laser's engagement area. Radar acquisition usually presages a laser "launch" though not always.

Ultimately, beam weapons win

This is an age old competition complex. The attacker can bring bigger weapons to bear and to survive the defender must wear/build ever heavier armor. Megawatt or gigawatt beam weapons simply aren't blockable or avoidable. And the ability of sensor networks to accurately track targets is only going to improve over time. There may be a short period where beam weapons can be mitigated by aircraft countermeasures but not for long if beam weapon power continues to increase at previous rates (and likely they will exponentially increase in power.)

• I would say avoid is the easiest. Radar systems are incapable of (reliably) tracking a small target skimming the surface of the water, closing in towards the radar system. This is how the current generation of Air to Sea missiles work. – Aron Sep 22 '15 at 10:29
• There is a limit for beam power, since the device firing the beam must also survive... And at that point we can just put the same material on the plane that the device uses. – Aify Sep 22 '15 at 16:53
• @Aron, I think the CIWS will beg to differ with you about tracking high speed, low level targets. – Green Sep 22 '15 at 17:06
• @Aify, that's true but the aircraft will need to make weight/performance trade-offs that the laser weapon doesn't have to make. Further, the plane must defend from all angles, while the laser only has to "defend" from two. – Green Sep 22 '15 at 17:08
• @Green Why does the laser only have to defend from 2 angles? Assuming the laser was placed on flat ground, the laser would have to defend a whole hemisphere's worth of angles. Also, like I've mentioned in my post comments, the advancement of better propulsion systems would allow for the plane designers to eventually ignore that weight problem. – Aify Sep 22 '15 at 17:48

Essentially, yes. With nuclear engines to power it up, the laser systems' effective rate of fire (rather low at the moment for current systems) may end up being limited only by equipment cooling requirements and the time it takes the turret to turn and acquire a new target. Moreover, unlike other projectile-based solutions, once a target is acquired, damage starts occurring instantaneously. With a battery of a few dozen of these miniaturized puppies, you can effectively blast away anything that enters your skyes from a range of 5km (horizon distance at sea level) to 100km (horizon at aircraft cruising altitude).

Aircraft cannot match the power supplies or sheer quantity of lasers on a floating (or fixed) platform. While some posters state that using superreflective materials would help, I disagree. Current beams can achieve unbelievable focus, properly ranged (and you have a laser ranging system, hehe), down to beam sizes mere nanometers across. Even the best mirrors have less than 100% reflectiveness, and would vaporize locally essentially instantly at 10MW power levels and above. This would ruin the mirroring effect further, and soon ablation effects would become significant.

Laser platforms in place would effectively create an aerial area denial zone until silenced by heavy hyper-velocity kinetic impactors (too heavy to laser-vaporize, too fast and heavy to use a Phalanx-like system against).

No. Powerful lasers don't mean the end of all aircraft. It means that usa is preparing to sell it's next generation of fighters with a powerful initiative.

As Aify and Green have mentioned before me, evolution is a constant process (even when it comes to weapons) and only the fittest survive. So all the weak species of aircrafts are going to get extinct pretty soon, agreed. But what about the species which are fit enough to survive? I will not be going into details here as Aify and Green have already discussed the matter in detail. My idea is that usa airforce has already finished building fighters which have laser defense system in them (whatever the method). So once all warships have the laser canons, usa would be in prime position to obtain orders for it's next generation of very expensive aircrafts.

Here's another way to fight laser weapons: A smoke screen. Just have your aircraft generate lots of smoke. That has two effects: First, it makes aiming harder (because you no longer see the aircraft), and second, it blocks the laser (because the laser power goes into heating the smoke instead of the airplane). A disadvantage is that smoke trails will be a dead giveaway that there's something in the sky, so you'll only generate that smoke as soon as the enemy knows you are there (e.g. by detecting their radar).

• The problem with the smoke would be deploying it in front of the aircraft to protect it, at military fighters speed that is not easy. Also, it may need lots of chemicals to provide smoke dense enough during all the travel of the plane. – SJuan76 Sep 22 '15 at 11:03

Let me start with the obvious reason why combat aircraft will remain in use - my aircraft will still be needed to operate in my airspace after my lasers have established air superiority for me. Current laser projects are being geared toward anti-aircraft efforts, but the number one goal is anti-missile systems.

Now let me give you a brief primer on how to fly over a basic anti-aircraft weapon.

Turrets are turrets, and they move as fast as the designers can make them move, but the overall goal of getting through an AA battery is to get from one side of the arc to the other without being annihilated. The classic training for this is "low and slow," because that got you safely through the narrower part of the arc pretty quickly. But that's gotten to be impractical against more modern AA batteries. Now it's more like "really low and stupid fast," because what you have to do is stay so low that the system simply isn't aware that you are a thing that should be shot at. But there's another point to be made here - if you avoid target lock, you don't get blasted. Electronic countermeasures come into play and you start calling in special platforms that make radar do stupid things.

Now, if these next generation systems move fast enough, we have some problems; but remember that basically anything that hits the laser station will basically end its role in the fight. If the optical pumping chamber can be even slightly misaligned or cracked, it's over. Shelling should do nicely, as the laser itself can't particularly stop a ballistic projectile, even if it could track it (and it probably could).

I think this warrants a new generation of aircraft. Instead of the million dollar fighter jets, we move on to fast, agile, thousand dollar drones (okay, more like 1 million). Deploy them in swarms, a hundred aircraft in a hemisphere around the enemy turret. One will make it through, and then, it's bye-bye laser. And then we bring out the normal aircraft, if we want to.

Obviously, some design considerations can make it even easier for you.

Shape: Drones should be rather pointed cylinders, with thin, large wings, to increase surface area per unit weight not exposed to the laser. Drones can be intelligently oriented with a reflective, ablative side towards the laser, and a dark radiative side facing away. Computer systems and engine can be in the center.

Engine: Get something with a relatively high flow rate (air is pretty bad coolant, but it's all we have), and fast. Scramjets seem to fit the bill. Thrust vectoring is a must for extra maneuverability.

Many Many missiles: Some carrying reflective dust/strips that make you harder to target and hit, some are actual missiles to destroy the laser.

Say the UAVs speed towards our ship at low altitudes at around mach 3-4. They'll cover 100 kilometers in slightly more than a minute. If one drone can be destroyed in 5 seconds once targeted, our drones can destroy the enemies' lasers with 12 casualties if they start targeting us at 100 km. It will be fairly expensive, but, hey, a F35 costs a few hundred million.

• In that case it becomes a economic war, not a military one. Can you build and maintain more drones than the enemy can build and maintain laser emplacements? It would be an interesting subject for a study of some kind. – moran Sep 23 '15 at 10:18
• @moran - In a sense it's already been done. One view of the end of the Cold War was that we simply bankrupted the USSR. – WhatRoughBeast Sep 23 '15 at 19:23
• @WhatRoughBeast Of course any war is largely won by logistics and economics. Germany would not so easily have been defeated if the economic might of America hadn't been put into play. – moran Sep 25 '15 at 6:33
• Really, I guess the drones aren't so much "Airplanes" as "Expensive, reusable missiles". – timuzhti Sep 25 '15 at 7:39

Defense. The aircraft can be covered in retroreflectors, or better yet, active phase-reversing amplifying reflector panels. This will not only protect the plane but destroy the laser instead.

Another thought here—attack where the laser can't fly. We already have rocket-boosted torpedoes, consider what happens if we put together state of the art technologies:

Stage 1 is an aircraft-launched missile. It's going to be a big missile, though. It stays below the horizon to the ship it's attacking, the laser is useless.

Now, eventually staying below that horizon will drive it into the water. Before this happens it shuts down its engine and trades its airspeed for lift—the intent is to bleed off as much speed as possible without hauling along extra mass to do so. Eventually the lifting surfaces stall, at this point the airframe is discarded, the payload comes away on a parachute.

Stage 2 goes into the ocean something like 30 miles from the target ship. It goes to it's preset depth and light it's rocket booster—it's a supercavitating torpedo. It roars for about 9 minutes, the target fleet will do what it can during that time to evade but there are a bunch of these coming and they are fired in a spread.

As the torpedoes approach the target area their rockets shut down and are jettisoned. Some are programmed to go a bit long, some a bit short.

Stage 3 is an ordinary anti-ship torpedo. The fleet has had enough time to break any targeting they might have had but they can acquire on their own. They can hope to interpose their decoys but the torpedoes are scattered beneath the fleet, they can't steer away from every torpedo. The torpedoes that don't come out of supercavitation at the right spot to engage start hunting. They could also trail an antenna wire and listen to instructions on where to find the enemy—the fleet is going to find itself surrounded by hostile torpedoes and you can't run from enemies surrounding you.

• This sounds overly complicated and expensive....when can you have it built? - USN – Marshall Tigerus Jun 29 '16 at 16:00