There’s a laser revolution coming: a time when megawatt-scale beams will radically transform how we produce electricity, conduct war and even upset the nuclear world order. All they have to do it reach a certain convergence of price and power. And by current projections, it will happen in the next two decades.  It’s hard to imagine a world without lasers. They’ve been around since 1960, when a ruby rod managed to produce a few watts of deep red coherent light. The first designs were costly, heavy and incredibly inefficient. But today they are both affordable and powerful, with widespread applications from entertaining light shows to cutting steel to delivering this blog’s content down fiber optic cables. Laser cutters in the 1-10 kW come standard in the automotive and aerospace industry. Soon, we'll have to consider a vastly expanded role for them, with serious consequences. In other words, a laser revolution. In this Part I, we'll describe how laser power vs price is progressing and how techniques are being developed to overcome the obstacles to beaming them through the air, then try to work out what consequences they'll have: first militarily, on the threat of nuclear weapons and how air warfare is conducted. In Part II, we'll continue looking at the consequences of ground and sea warfare, before expanding on the civilian side and the exciting opportunities megawatt lasers will create, from space launch to power generation. Powerful Lasers What exactly is a ‘revolutionary’ laser? It can only be described in relation to current output and price levels. Lasers are getting more power and cheaper at the same time, following a progression that resembles Moore’s law. The sorts of lasers you personally have access to range from milliwatts to kilowatts. The smallest are so cheap and widespread that they can be bought from local stores.  Lockheed Martin's HELSI program wants this box to produce a 500 kW laser You can order a 1 watt laser pointer online for around $150, and a 10 watt laser module for around $350. Kilowatt-scale fiber lasers are advertised at under $1800. Regular businesses can access commercially available 10 kW-class lasers, such as a laser cutting machine that is listed for around $100,000, and 100 kW-class lasers aren’t far away. You can buy a 100 kW CW fibre laser from Raycus. Now. These are all relatively efficient designs with good beam quality, continuous output and operate in near-infrared to visible wavelengths.  Here are rough costs of beam sources by wavelength, from GerritB: Infrared lasers would be around $100/watt, while visible wavelength lasers achieved through frequency doubling or tripling sit above $1000/watt. Lasers as ‘complete packages’, including a power source, cooling, optical train and a mirror to focus them over long distances also exist in the 10 kW scale. Military designs like the Raytheon HELWS H4 fit on the back of a pickup truck and have undergone 25,000 hours of testing, managing up to 15 kW at full power from atop a British Army Wolfhound. Raytheon's palletized laser weapon in the back of a pickup truck.  Rafael’s Iron Beam is a container-sized air defense system with 100 kW output, and its mobile version focuses 50 kW through a 25 cm beam director. DARPA’s HELLADS is developing a 150 kW laser with the goal of 200 W/kg power density and fitting inside 3 m^3, allowing it to be mounted on small vehicles and aircraft. Meanwhile, the US Navy’s HELCAP is testing 300 kW lasers aboard Arleigh Burke destroyers. These are all effective and affordable for their users, which are militaries with big budgets.  The US Army's HEL-TD on an Oshkosh HEMTT truck. A ‘revolutionary’ laser is the next step up: 1 to 10 MW output, with even better efficiency and beam quality, yet more affordable. Megawatt-scale lasers are already expected before 2030 based on development contracts and other reports. An AFRL publication predicted directed energy weapons in the 100 - 1000 MW range by 2060, so this is on the right track. We’re looking at current trends to determine when they will acquire revolutionary qualities. Here’s what they look like: Rapid decreases in $/W are expected in the next decades. This chart gives us exponential fits we could use. A flattening curve is more realistic, but it's still rapid progression. In fact, the progression of laser brilliance has been compared to Moore’s law for the number of transistors on a chip: From these trends, it looks like lasers will become roughly 100 times cheaper per watt by 2045. If you believe this timeline is too aggressive, then add 5, 10, 15 years to the estimate and you’ll find the conclusions of the rest of the post will remain the same. Regardless, it means 1 MW of raw infrared diode laser output will have a price on the order of $10,000, while visible wavelength lasers would be several tens of thousands of dollars. Increasing beam quality or shortening the wavelength will cost more, but costs remain within that order of magnitude. Achieving this might require combining 1000 fiber-laser modules of 1 kW each, a ten-fold improvement over the roughly 100 module coherent beam combining possible today. Experimental set-up for combining 100 beams. ‘Full package’ lasers as described above will likely match appropriate cooling equipment and correctly sized optics to the increased laser power, but they won’t see a 100x price decrease. The laser generator inside can be compared to the engine of a car: an essential component that contributes significantly to the cost of the full vehicle, but cannot eliminate the price tag on its own.  AFRL's roadmap for laser weapons. Military equipment is very expensive. Existing devices that can track a rapidly moving target and point a laser at it, like a LITENING pod with its 10 cm aperture and many sensors, costs $3 million. The newer 15 cm Sniper Advanced Targeting Pod has been sold in contracts for $3.3 million each. Turkey’s equivalent ASELPOD goes for $1.5 million. The 'Sniper' ATP. A 2024 congressional report on shipboard solid-state lasers for the US Navy estimates that a 60 kW laser weapon costs $100 million, while a 250 kW weapon would reach $200 million. These are within the cost bracket of existing kinetic (gun, missile) based weapon systems, so their only advantage is that their ‘ammunition’ is electricity instead of expensive missiles (one SM-6 interceptor missile is over $4.8m). The report suggests that the cost of a ‘full package’ laser is not strongly tied to the beam power; by its estimates, a 4x more powerful weapon is less than 2x as expensive. Based only on this sort of data, it’s more likely that 1 - 10 MW lasers will remain very expensive even as their laser generating components get much cheaper, allowing them to increase their output. For example, today’s $100 million design that outputs 100 kW might still cost $100 million in 2030, but output 1 MW. Everyone gets a laser. On the other hand, lasers are clearly a technology that is still developing rapidly, leaving an immature early phase where they’re very expensive and progressing in leaps and bounds to a settled status where only incremental improvements remain. We mustn't forget how much progress can be made in 20 years of rapid development. Aviation progress in the 60s, which resulted in the XB-70, could be the model for today's lasers. In 1945, the first P-80 Shooting Stars were produced for the USAAF. At 956 km/h, their engines had an output of 5.3 MW each. In 1965, the XB-70 Valkyrie broke Mach 3. Its six engines had a combined output of 662 MW at 3310 km/h, making each engine 21 times more powerful than the one on the P-80. Meanwhile, the commercial aviation industry had access to Boeing 727s with 3x17 MW engines or The Vickers VC10 with 4x24 MW engines. A PowerLight beaming demonstration, one of the few long-range laser developments with near-term civilian uses. A look at commercial equipment paints a more promising picture. Heat exchangers, coolant pumps, power handling equipment and large mirrors on precision mountings are not seeing the same dramatic price drops year after year as laser generators do, but they are making relatively rapid progress.  For example, when it comes to electrical power handling, the PNNL Grid Energy Storage Technology Cost and Performance Assessment from 2022 placed rectifier plus inverter costs at only $0.123/Watt. This figure is for a fixed installation, so a mobile version would cost more. Commercially available ‘deluxe’ 28 cm telescopes with a robotic mount and computer control come in under $8000. How much effort is needed to turn this into a laser mount? A half-meter telescope can cost a few tens of thousands of dollars. A meter-wide mirror in its mount is around $100,000 while a whole astronomy-grade observatory with tracking motors is more like $250,000 to $500,000. A "low-cost, 0.5 meter, robotic telescope" for DEMONEX. A laser might need special low-expansion glass like ZERODUR with a cooling system attached, which would raise the cost of a full mount with a meter-wide mirror by up to an order of magnitude. ZERODUR low thermal expansion glass. However, if efforts like Trex/ABT’s attempt to reduce the cost of telescope-grade mirrors to $100,000/m^2 by using diffusion-bonded (no adhesive) CVC silicon carbide instead of traditionally machined and polished glass are successful, then the costs wouldn’t rise so much. They would instead start to fit pre-existing scaling laws.  So, based on these commercial figures, a 1 megawatt laser generator paired with a robotic mount, large low-expansion mirror, sufficient cooling and power-handling modules adds up to around $1 million in the near future, or at worst $10 million. This excludes the power source, which depends on the laser’s intended use.  In summary, a pessimistic progression for 1 MW lasers would place them in the $100 million bracket by 2045, an optimistic one would have them under $1 million, while a realistic one would be somewhere around $10 million. At that price, we obtain something more than a mere improvement over current lasers - it’ll be revolutionary. Beaming Megawatts Bad weather conditions can render today's lasers difficult to use. Powerful lasers are an oft-visited topic at ToughSF. However, they are usually considered for use in space, where their beams travel through a vacuum. It allows us to basically ignore what happens to the beam as it travels between its focusing mirror and its destination. The diffraction equation (spot size = 1.27 x wavelength x target distance / mirror diameter) tells us almost everything we need to know, so maximizing beam range and effectiveness means simply looking for the beam with the shortest wavelength focused by the largest mirror possible. For lasers inside the atmosphere, there are other factors that cannot be ignored. There are at least nine types of beam-air interaction, including two-photon absorption, stimulated scattering, ionization, cascade breakdown and filamentation. Thankfully, most of these are only relevant to very intense lasers or wavelengths considered to be ‘vacuum-only frequencies’, such as X-rays. The megawatt-class lasers of the next decades are expected to have infrared or visible wavelength beams with continuous output, operating far below the intensities needed to tear apart air molecules, so instead we have to deal with thermal blooming, both types of attenuation and twinkling. Thermal blooming A powerful beam travelling through the atmosphere will heat up a channel of air along its path. Hot air has a lower density than cold air. Just like a mirage in a desert is the result of hot air bending light, a channel of hot air will act like a lens that de-focuses a laser travelling through it. The more intense the beam and the longer it heats the air, the stronger the de-focusing effect. The simplest solution to thermal blooming is to reduce the lasing time. A short burst of power doesn’t heat up the air so much. The continuous-wave lasers of the next decades might not have the capability to concentrate their power into pulses, or we may need them to keep beaming for extended periods, so this isn’t always an applicable solution. Another simple solution is to let the beam wander in circles, so it is always moving out of its own hot air channel into fresh air. This is great if the target is also moving, but not so great if the beam must remain focused on a single spot.  How much will this affect a powerful laser? There are equations to estimate the level of distortion. We find that for a visible or near-infrared laser of 1 MW focused by a 1 meter diameter mirror, focused onto a 1 cm spot 50 kilometers away, the effect of thermal blooming can be ignored. For lasers ten times more powerful, we must counter the blooming with linear adaptive optics. How adaptive optics work. It’s 100 MW lasers and beyond that need additional corrective actions, or hope for a slight wind to help clear their hot air channel.       Twinkling  Stars twinkle because their light is distorted as it travels down through the turbulent atmosphere. Lasers twinkle too when the medium they travel through moves randomly and deflects the beam.  Astronomers found a solution to provide clear images to their telescopes. They use adaptive optics that detect the level of distortion in the light being received with a wavefront sense, then bend their mirror accordingly to negate those distortions.  Lasers can also use adaptive optics, to correct twinkling and many other types of distortion.  Attenuation from atmospheric absorption This sort of attenuation is caused by the air absorbing light passing through it. Our terrestrial mix of oxygen, nitrogen, carbon dioxide and water vapour is extremely unfriendly to wavelengths shorter than UV. Water vapour makes many infrared wavelengths unsuitable as well. Taking these into account gives us ‘transmission windows’ that are ideal for a laser to exploit. Here’s a chart: You want to minimize laser divergence to increase its range and form a smaller spot with the beam at its target, so the ideal laser uses the shortest wavelength within these transmission windows. Agatha’s analysis suggests that 400 nm lasers (cyan) are the best for going through an atmosphere from top to bottom. Deep blue lasers seem to be optimal. However, a practical laser may choose to sacrifice some performance in ideal conditions to get some better ability to handle water vapour. Weather conditions like cloud cover or fog can place a lot of water in the beam’s path. The more water the laser is expected to encounter, the more interest there is in a green laser (around 500 nm) rather than a blue one, as that is the wavelength that gets through water the best. Going through water imposes another constraint. Other practical considerations include the nature of the laser generator; a CO2 laser may only offer long infrared 9600 or 10600 nanometer wavelength beams. A modern diode-pumped solid state laser using a GaAlAs diode and Nd:YAG lasing crystal produces a 1064 nm beam, which is commonly frequency-doubled to 532 nm (this is where we get green laser pointers), which is slightly longer than the 500 nm optimal for penetrating water.  Let’s try to estimate the effect of this type of attenuation. Chart from the Galactic Library, by Luke Campbell! In dry air, a 500 nm beam has an absorption length in the tens of millions of kilometers. It means the laser has to travel that distance through air to lose 63% of its power. Adding in 1% water by volume (corresponding to 60% relative humidity), this length decreases to a few thousands of kilometers. Earth’s atmosphere is 100 kilometers deep vertically, close to 1000 km deep tangentially from the horizon. So, we can ignore this type of attenuation for green lasers. A deep red or near-infrared laser fares much worse, with an absorption length as short as 10 km. That means it will lose 86% of its power after travelling two absorption lengths, or 20 km. A laser with a short absorption length suffers the double trouble of more intense thermal blooming, as the air along its path is more easily heated up. Attenuation from aerosols If you can see a laser beam, then it means the beam is losing energy to scattered light. For air- and water-penetrating wavelengths, the attenuation caused by various small particles in the atmosphere, such as water droplets and dust, is much more relevant.  The effect is very difficult to estimate because of the variety of conditions that can exist. A general rule of thumb to follow is that if your sensors can see a target, then a laser can reach it too. This is especially true if the main focusing optics for the laser also serves to collect light for the sensor. If your sensors cannot get a good image of the target, then a laser won’t reach it easily either. A useful estimate for how much aerosols affect visible wavelength lasers is the meteorological visibility scale: it can range from perfectly clear conditions where visibility exceeds 50 km, to dense fog where visibility is less than 50 meters. A visible wavelength laser would have the same effective range as this visibility scale. Empirical testing for how lasers traverse various weather conditions has been done. Balloon and searchlight data at 550 nm gives a wide range of attenuation coefficients: We see on the chart that at ground level, aerosol attenuation coefficient is roughly 0.01/km, meaning that traversing 20 km saps away 1 - e^(- 20 x 0.01) = 0.181 or 18% of the laser energy.  Transmitting 550 nm lasers across in Chesapeake Bay in humid conditions, a distance of 5.5 to 16.25 km, leads to losses of 50 to 70% of the original beam power: A more modern study of laser communications finds an attenuation coefficient as high as 0.04 at 500 nm near the ground, so across 20 km, this is 55% of the beam being lost to aerosols. Meanwhile, a LIDAR study gives data on transmission of different wavelengths through bad weather: Since aerosols scatter the laser light in all directions, it is difficult or impossible to counter the effects using adaptive optics from the laser source. So it is a major challenge for lasers to overcome.  Are there ways to deal with aerosols?  A proposal to clear fog over airports using hundreds of megawatts of infrared lasers. A brute-force solution is to vaporize all the water in the beam’s path. Turning water droplets into water vapour means there are no more particles that can affect the beam via Mie scattering (from particles close to the scale of the laser wavelength) or Rayleigh scattering (from particles smaller than the laser wavelength). However, boiling water costs a lot of energy. Luke Campbell has this to say: “I find that a cloud has 1 to 4 kg of water per square meter per kilometer thickness, but rarely exceeds 2.5 kg/m^2 per km thickness. Considering only the heat of vaporization, it will take about 5.5 MJ to evaporate a one square meter hole through a kilometer thick cloud. The most extreme cases we will have to deal with include nimbostratus clouds and cumulonimbus clouds. The former tend to be 2 to 3 km thick with extreme examples up to 4.5 km thick, the latter average 2 km in height but in extreme cases can reach 20 km high. This leads to 10 to 15 MJ to burn a one square meter hole through typical heavy rain clouds and thunderstorms, with extremes of 100 MJ to burn a 1 m^2 hole through the highest thunderstorms. Once a tunnel is formed through the cloud, you will need an additional input of power to keep that tunnel clear as wind blows additional cloud droplets into the tunnel. The power required will be the energy needed per square meter to form the cloud tunnel times the wind speed times the tunnel diameter. For a 2 km thunderstorm with 10 m/s winds, a 1 m^2 hole will thus require a power of ~100 MW to keep the tunnel open. 2 km thick heavy rain clouds with 3 m/s winds will require 30 MW to keep the tunnel open. As the radius of the beam increases, the initial energy to form the tunnel scales with the square of the beam diameter, while the power to keep the tunnel open scales linearly with beam diameter.” Based on the above, the upper limit of laser power needed to cut a channel through the worst weather conditions is 100 MW/m^2. If the total laser power available is 1 MW, then it can only vaporize a 0.01 m^2 hole through clouds in its path, which is a circle about 11 cm wide. Limiting the diameter of the beam restricts its range due to the diffraction limit. A beam that’s normally 1 meter in diameter, that’s restricted to 11 cm in diameter, would have a range 9 times shorter.  Thick fog would place similar amounts of water in the beam’s path, but the wind speed would be lower (strong winds break up fog). ‘Regular’ weather consisting of white clouds a few hundred meters thick would still require over a megawatt to clear in a light breeze.  Clouds by type and altitude. Lasers from the next 20 years won’t have the power output to spend 1-100 MW just to clear a channel through clouds. So, their effectiveness will depend on the weather. If a target flies into a large cloud, it cannot be reached by lasers. If thick fog descends on a laser-equipped site, it might be put out of action.  But, there are other options. There have been claims of existing lasers being able to circumvent wind and fog despite only having kW-level outputs.  There are methods to clear a path for lasers through clouds or fog in a much more efficient manner. Two laboratory- or field-tested techniques stand out: -Shattering the water droplets This technique attempts to reduce the size of the water droplets so that they are no longer close to the wavelength of the laser. The light scattering effect from aerosols becomes much weaker once the aerosol and the laser wavelength don’t match up. For example, reducing the droplets to a size 10x smaller decreases the scattering effect by 10,000x! One approach is to use an intense pulsed laser that only vaporizes a portion of the water droplet, turning it into a superheated mass that explodes and destroys the rest of the droplet. This costs much less energy than vaporizing the whole droplet. According to this study, a channel can be cleared through clouds and fog by splitting droplets with at least 7x less energy than fully vaporizing the droplets. Shockwave generation inside droplets by picosecond lasers. Another paper suggests that laser pulses of 0.1 to 6.5 J/cm^2 are enough to shatter droplets across all weather conditions, compared to 33 to 500 J/cm^2 for complete vaporization, meaning that shattering droplets can be 76x to 330x more efficient that the brute-force method. An energy cost 0.8 to 2.5 J/cm^2 is suggested here. Finally, a figure of 1.2 J/cm^2 is said to be enough to clear a channel through clouds by shattering droplets that lasts for half a second, meaning an average power output of 24 kW/m^2 is sufficient.  If we average these results we get an upper end of 50 kW/m^2 for shattering water droplets. This is only 5% of the power output of the 1 MW ‘main beam’, but it must be delivered in the form of short intense pulses. If the long wavelengths described in the papers above (10.6 microns) is also a requirement, then it becomes necessary to deliver these pulses via a separate dedicated mid-infrared laser that is installed parallel to the ‘main beam’ laser. If an intense pulse of any wavelength is enough to produce these effects, then a Q-switch can be added to the ‘main beam’ to give it a pulsed mode of operation.  -Dispersing the droplets with shockwaves A plasma filament generated in air by a femtosecond laser. This technique aims to simply move the water droplets out of the way. Ultra-intense laser pulses can generate self-focusing plasma filaments in air; essentially brightly visible lightning bolts that travel in a straight line for their entire length. These filaments mostly ignore beam divergence or other dispersion effects, and modern techniques are able to extend them into “megafilaments” of dozens of meters, potentially hundreds of meters. They’re also only a few micrometers in diameter, and explode after a few microsecond.  This means it is unrealistic for laser filaments to propagate across kilometers to their target, especially not when channeling ‘main beam’ power of over 1 MW. Instead, their explosive end can be used to generate a pressure wave that sweeps water droplets out of a channel of air surrounding the filament.  Experimental data shows that a 1.3 picosecond laser with pulsed power of 76 GW was able to create plasma filaments in air that were 50 cm long. The shockwave and expanding hot air from the exploding filaments was able to accelerate surrounding water droplets to 60 mm/s, which was enough to clear out a channel through fog if the pulse rate exceeded 1 kHz. However, they only assume a cleared channel width of 100 micrometers. That is far too small to send a ‘main beam’ through.  633nm laser going through a cloud before and after droplet scattering. Another experiment used 0.05 picosecond pulses with a peak power of 100 GW. The Ti:Sapphire laser could generate red (800 nm) or blue (400 nm) wavelengths. The cleared channel was measured to be around 1 to 2 millimeters in diameter (FWHM 1.6 mm in the best case), that lasted for more than 90 milliseconds. It means a laser pulse frequency as low as 10 Hz could be enough to keep the channel open. Still, it is far too small to be useful for a ‘main beam’.  Multiple other sources confirm that channel diameter is in the millimeter range when using 0.1 J-scale pulses. Theoretically, if the cleared channel is a long thin cylinder with the plasma filament at its center, its diameter would scale with the square of the pulse energy. 10,000x the pulse energy would heat up the plasma filament 10,000x more, causing it to expand 100x further. That means 1 kJ pulses could potentially clear out channels a meter wide. If the pulse frequency can also be as low as 10 Hz, then about 10 kW of average laser power is sufficient to clear meter-wide channels. But that is very optimistic, as the channel diameter scaling is likely to have a 3D component (explosions expand in all directions), and the picosecond timescale of these pulses means the laser’s peak power has to be in the 1000 J / 10^-15 s = 10^18 Watt range. This is what a 10^16 Watt laser facility producing 1.5 kJ pulses looks like: You’d need 100 of those facilities. It’s not practical.  There is hope for a practical solution in “Molecular Quantum Wakes”: Without generating plasma nor laser filaments, an acoustic wave is formed to move water droplets out of a wide channel. The laser pulses act on the air itself to create a strong temperature gradient, which launches the acoustic wave. It seems that eight pulses with a total energy of 3.8 mJ are enough to clear a 0.5 mm radius channel that’s 10 cm long. That’s an energy cost of 4.8 kJ/m^2. If the 10 Hz pulse frequency requirements from previous channel-clearing studies holds, and energy requirements scale up by area, then a pulsed laser with 38 kW average power is enough to clear a path for 1m wide ‘main beam’. As before, this can be delivered by a pulsed mode of operation using a Q-switch ‘adaptor’ to the powerful continuous laser.    In the next sections, we try to work out the consequences of powerful yet affordable lasers becoming available in the next 20 years.  Overthrowing the Nuclear Order Missile interception test, at night. We can start with the most dramatic and disruptive effect. Consider a 1 MW laser producing a 532 nm wavelength beam, focused by a 1 meter wide mirror fitted with adaptive optics to counter thermal bloom and twinkling, operating at 50% efficiency once cooling and power handling losses are included. It is fed by 2 MW of electricity.  Accounting for beam jitter and atmospheric interference, it can focus its beam onto a 20 cm diameter spot at 200 km (about 1.5x the diffraction limit). This translates into a spot intensity of 32 MW/m^2 or 3.2 kW/cm^2. The laser damage calculator finds that this is enough to burn through 6 mm/s of aluminium alloy, 1 mm/s of stainless steel or 0.18 mm/s of graphite. Test of the UK's Dragonfire laser. At 50 km, the spot diameter tightens to 5 cm, raising the drilling rate to 8.2 cm/s of aluminium alloys or 0.95 cm/s of stainless steel. At 10 km, these increase again to an astounding 122 cm/s of aluminium alloys or 20 cm/s of stainless steel. The laser would actually prefer to not reduce the spot diameter below 1 cm at closer distances to avoid thermal blooming effects. It would remain a destructive weapon regardless, capable of boring holes all the way through flying targets instead of meekly trying to cut off fins or ignite onboard fuel.  Their ultimate test would be a nuclear attack. From the US, it can be delivered in three ways: a low-altitude cruise missile like the AGM-86B, a bomb from aircraft like the B-2 or F-15E, or the re-entering warhead of an ICBM like the Minuteman III.  An AGM-86B is likely to be detected by an air defence radar as soon as it rises over the horizon, perhaps from 20 km away. B-52H dropping an AGM-86B cruise missile. Travelling at 900 km/h, there is an interception window of 80 seconds. The 1 MW laser would start by cutting through 61 cm of aluminium alloy per second, and its penetration rate increases exponentially from there…. which means it only needs to dwell 3.3 - 16.4 milliseconds on each missile to get through their 2 - 10 mm of aluminium. In fact, if we use the 1-10 kJ/cm^2 “hardness” rating of missiles, we get similarly short dwell times of 3.1 - 31 milliseconds.   That delay is practically insignificant compared to the switching time between targets. If we assume it takes 1 second to switch between targets, and cut off the last kilometer from the engagement as the laser turret may not be able to slew fast enough to track its targets at the short distance, then we get 75 missiles shot down. Internal bay of the B-1 Lancer with rotating rack of cruise missiles. One single $10 million defender, with sufficient sensor infrastructure highlighting its targets, could take out the payload of three B-1 Lancers or nearly four fully-loaded B-52 bombers. Newer, stealthier AGM-158s for the B-52 This forces the use of massively more missiles per attack, or a replacement of the majority of existing cruise missile arsenals by costly stealthy designs like the AGM-158 family. Aircraft find themselves in a worse position. Radar arrays like the S-400’s 1N6E primary search radar might detect an older non-stealthy fighter like the F-15E from a distance of 200 km. In the time the pilot takes to notice their radar warning tone, pull on the stick and start diving to the ground, a 1 MW laser weapon would have drilled through several millimeters of aluminium. If the plane is exposed for three whole seconds at that distance, it would have already exceeded its 10,000 J/cm^2 hardness rating.  A stealthy aircraft like the F-35 fighter or the B-2 bomber might not be detected (or more importantly, tracked!) before they are able to deploy their weapons and turn away. F-35A dropping a B61-12 nuclear bomb from an internal bay. That would prevent them from being engaged by a laser at extreme range. Though, if they encounter a radar site at an unexpected angle, face an advanced infrared or electro-optical sensor, or increase their radar signature when deploying weapons, they they'll be detected, starting a 0.03s (at 20 km) to 3s (at 200 km) clock on their expected lifetime (plus up to 1 second for the laser turret to swing around). And while their platform might be stealthy, nuclear bombs in the air won’t be. A disassembled B61 bomb reveals its steel case isn't very thick Large bombs can have steel casings 25 mm thick, yet it still only takes a 1 MW laser about 0.01 seconds to drill through it from a distance of 10 km. Target switching time dominates again. Even if the B61 bombs are released by a supersonic throw, they’d take about 30 seconds to reach their target, meaning one 1 MW laser defender can take out 29 of them. Toss bombing is seeing use in the Ukraine war. So, the laser weapon forces air-launched nuclear attacks to be carried by expensive stealth platforms, and be fitted into stealth packages themselves. That excludes the existing arsenals of unguided bombs, including the USA’s 950 B61s or Russia’s few hundred non-strategic air-dropped warheads, and severely limits the number of potential launch platforms. There are only 19 B-2 Spirit bombers, for example, and about 300 F-35As, compared to 300 F-15s, 800+ F-16s and 900+ F-18s.   ICBM attack creates the hardest targets. Their MIRV warheads enter the atmosphere at near-orbital velocities and do not slow down much until they hit the ground. Falling stars of destruction. While drifting in space, they can deploy massive numbers of decoys to complicate interception, and might even pre-detonate some nukes at high altitude to mess with radar targeting. A large number of decoys makes it impractical to intercept a nuclear strike in space using missiles. Once they enter the atmosphere however, at an altitude of 100 km, the decoys are separated from the dense warheads and the laser engagement can begin in earnest.  At a 10 degree re-entry angle, the MIRVs traverse 567 km at 7.3 km/s before reaching the ground. At a 60 degree re-entry angle, they only traverse 115 km at 9.6 km/s. This is the range of re-entry trajectories. Re-entry warhead hardness is around 25 kJ/cm^2 to 100 kJ/cm^2. We'll use the higher rating. At 567 km, it takes the 1 MW green laser with a 1m diameter mirror over 115 seconds to accumulate 100 kJ/cm^2 of damage. At 115 km, this is reduced to 4.8 seconds. At around 53 km, the laser is eliminating one warhead per second, and further intercepts are almost entirely limited by the target switching delays.  Spinning and covered in ablative shielding, MIRV warheads are already well protected from lasers. If we work iteratively in 0.1 second steps, and add 1 second of target switching delay each time the laser damage accumulates to 100 kJ/cm^2, then a 1 MW defender can intercept 13 warheads in the 10 degree re-entry scenario, down to 7 warheads in the 60 degree scenario. Within the final 50 kilometers, target switching time by far dominates over the warhead destruction time.  These don’t seem like impressive numbers, but they must be put into perspective: this is accomplished by a defence system that costs as much as a single SM-3 Block IB that can intercept one warhead at best. Lasers can operate indefinitely, putting a minimum threshold of 7-13 nuclear warheads per turret to push an attack through. This defence cannot be depleted by repeated attacks, and the lightspeed beam has a strong advantage against maneuvers meant to throw off kinetic interceptors.  Rafael's Iron Beam operates from a standard-sized self-sufficient container that can be placed anywhere. Theoretically, spending $1 billion on laser defences (with radar already available) would shield any site from nuclear attacks of 700-1300 warheads. That’s nearly all the active nuclear warheads Russia has ready for launch, even after they’re forced to arrive at one location within the same one-minute window. We also find that small increases in the cost of each turret (perhaps by doubling their mirror diameter to 2m and increasing their cost to $12m each) massively increases the number of warheads taken out, by 50% or more. Practically, raising the threshold for a nuclear attack to roughly 100 warheads, at the cost of $100 million, is enough to greatly trouble the largest nuclear powers as they can no longer divide their strike across dozens of targets; they’d have to concentrate their nukes on a few heavily defended locations and thereby become unable to guarantee ‘complete destruction’ of their opponent.  The 'ready to launch' arsenal of nuclear nations. The nuclear capability of smaller nations, like France, the UK, India, Pakistan, Israel and North Korea, who only have a few hundred to a few dozen active warheads, could be countered by laser defences worth $100m or less. As a reference, a single Patriot battery has a domestic cost of $1000m and an export cost of $2500m while an S-400 battery is sold for $1125m. Even if laser anti-ballistic missile defences end up being as expensive as existing missile-based defences, we're dealing with an expendable vs an unlimited system. Both usually come with 32 missiles, which is worth 16-32 intercepts depending on whether warheads are single- or double-targeted. They then have to spend up to an hour reloading. Truck-mounted MEADS air defence radar, costing around $30m. The radar and control elements are about half the cost ($500m) of these air defense batteries, meaning an equivalent a laser defence system with the same elements and total cost but missiles replaced by 1 MW beam turrets would be able to take out 350-500 warheads, and be ready for the next engagement in seconds. Cheaper radar systems would multiply this number. And as we will find out later, protection against nuclear strikes is also excellent defence against conventional attack, and building up laser defences for one purpose grants the other.  However, anti-ICBM laser defences like these would come with limitations. They only cover a single site, so the investment into 1 MW turrets would have to be multiplied for each location that needs protection. They are dependent on sensor systems to find and track their targets: half the cost of the Patriot missile battery is in its radar systems, and multiplying radar sites might not be economically feasible.  Lasers would only serve the 'terminal defence' role. Laser weapons are tied to their power generators and become useless if they are cut off. A mobile application must drag along multiple megawatts of power generating capability for each turret. We discussed how techniques for clearing channels through clouds and fog could become available, but megawatt lasers would still retain a vulnerability to bad weather. Nations could suddenly change from ‘immune to nuclear attack’ to ‘partially exposed’ over the course of hours because of a random thunderstorm or hurricane. It's possible that the level of sensor support needed to make use of laser defences prevents any significant cost saving... The warheads themselves could be fitted with armor to better resist laser beams. It could be an easy retrofit, like an additional cone of ablative material fitted onto the warheads, that serves mainly to extend the firing time needed to take them out at long ranges (100 km+). However, by the time the warheads enter ranges of 50 km or below, the time-to-destruction is measured in milliseconds and additional armor does not meaningfully reduce the total number of warheads destroyed. In fact, raising the amount of damage needed to destroy a warhead from 100 kJ/cm^2 to 300 kJ/cm^2 only reduces the number of warheads eliminated in the harshest 60 degree 9.6 km/s scenario from 7 per turret to 4. Raising it to 600 kJ/cm^2 reduces the number eliminated to 3. It’s an exponential race the attackers will lose to the defenders. Worse, the warheads become heavier, so each ICBM has to be loaded with fewer warheads, further diluting any nuclear strike capabilities. What does this all mean for the Nuclear Order that has kept nuclear-armed nations from engaging in all-out war for the past 80 years? The notorious Plan A simulation. It becomes weaker and less reliable. Most nations would be able to afford laser defences that raise the threshold of nuclear attack to several dozen warheads. Their existence requires entire arsenals to be refreshed, with older portions rendered obsolete decades before their planned end-of-life. Certain avenues of attack, like France’s airborne nuclear strike capability relying on ASMPs carried by Rafales and Mirage 2000Ns, would become totally infeasible. Because France has a nuclear arsenal that cannot entirely destroy its enemies, it must brandish it aggressively. Dispersed submarines who are only able to deliver 32, 48 or 60 warheads per strike would not be effective against defended sites; they’d have to group up and coordinate their strikes, rendering them less flexible and vulnerable to anti-submarine warfare efforts. ICBM arsenals that nuclear nations have spent decades and billions of dollars building up would become ineffective faster than they can be updated. The US is currently engaged in a twenty-year-long replacement of its Minuteman III ICBMs by the LGM-35 Sentinel, which are expected to operate until 2075. There are concerns Russia is unable to maintain its existing nuclear arsenal, let alone rebuild it with advanced missiles. Megawatt-scale lasers pointed at the sky might render this effort pointless long before then. Russia is still counting four-decades-old missiles among its active nuclear arsenal. These are the largest nuclear powers, and they take two to four decades to renew their arsenal, let alone expand it to deal with additional defences… if expansion is even allowed under anti-proliferation treaties.  Updated ICBMs for the laser era would be much larger, so that they can lift heavy warheads coated in thick ablative shielding. Air delivery would remain an option if both the launch platforms and the payloads become stealthy or fast; such as B-21s carrying AGM-158 LRASMs or ‘Dark Eagle’ LRHWs, but they'd be far less numerous than before. The B-21 Raider. Sneakier and more aggressive tactics would be favoured. Nuclear policy will shift towards more confrontational use, more along the lines of French rejection of no-first-strike and Russian threats of tactical deployment. All this is expensive, in dollars, time and political capital.  Less fortunate nuclear powers like Pakistan would feel the most threatened by the arrival of cheap yet powerful missile interception systems. They are the least able to sustain the expense of maintaining their nuclear offensive capabilities. However, countries with moderate military budgets and neighbouring nuclear states would have a lot to gain. For example, Taiwan could render its six largest cities nearly immune to a 100-warhead strike over the course of 5 years, using 6 x ($100 million lasers + $500 million radars) / ($16.5 billion x 5 years) = 4.4% of their military budget. Japan could do it for 1.3%, Australia for 2.1%. Then, in one further year of similar spending but without purchasing new radars, they would quintuple the effectiveness of their laser shields to 500 warheads. China is thought to have only about 400 warheads in an ‘undeployed’ state. So, it could find itself surrounded by nations who can flout its nuclear threat within a couple of years.  Chinese DF-41 ICBMs, capable of carrying 3x 425 kT yield warheads. Overall, weaker nuclear strike capability means a weaker nuclear deterrent, but it is not completely gone. Even the richest nations cannot protect all of their cities and infrastructure without spending billions upon billions of dollars. The political fallout from raising a full-scale anti-ballistic missile shield would be terrible, like starting a bonfire calling for immediate nuclear war. Instead, megawatt-scale lasers are the boiling pot, gradually raising the warhead threshold for nuclear strikes while keeping major nuclear powers vulnerable to severe damage from each other. But there will be consequences. An attempt to map the aftermath of an all-out nuclear strike. Suppose the United States raised a 100-warhead shield over its ten largest cities and ten more significant industrial or military sites, like Port Arthur Refinery in Texas and Eglin Air Force Base in Florida, at the cost of $12 billion. If it tried invading Russia, then Russia could concentrate 1000 warheads onto 5 targets, overmatching their local defences and exacting a terrible cost. The United States would not pay that cost to defeat Russia, so some nuclear deterrence remains. However, if India raised that same shield over its major cities and went to war with Pakistan, the latter’s 170 warheads could only hope to annihilate one Indian city. Perhaps that is a cost someone would be willing to pay to defeat a nuclear rival…  In another scenario, South Korea easily builds a number of laser interceptors that renders its entire territory immune to North Korean ICBMs. By military logic, this forces North Korea to act as soon as the laser turrets start appearing, before its nuclear threat is neutered. In fact, it would be in its interest to spend its nuclear card as soon as possible (either attacking with it or negotiating a disarmament while that still matters) before laser interceptors raise the threshold too far.  In short, megawatt scale lasers used to intercept nuclear strikes will create more openings for international aggression, embolden nuclear states in acting against each other, while also increasing pressure to both expand nuclear weapon arsenals while making them more menacing.  The Air War Lockheed Martin's 300 kW IFPC-HEL demonstrator. With 3x the power, it will take out fighter jets. There are many more military consequences to revolutionary lasers. The effects on aviation would be extreme. Some of this has been discussed in a previous blog post. As suggested in calculations in the previous section, aircraft survivability in the face of 1 MW laser beams focused by 1m diameter mirrors is a few seconds at the extreme range of 200 km. Long-range weapons like the massive Kh-28 or the AGM-88 HARM require the aircraft to come within 40-80 km of their ground target. These are today considered ‘standoff’ weapons, but they’d force aircraft to come to a distance where expected lifetime under laser fire is less than half a second. An EA-18G Growler with 4x AGM-88E missiles. Using shorter ranged weapons, like AGM-65 Mavericks, Kh-29s or any regular bomb like the GBU-24, would require aircraft to enter conditions where they can be cut in half in a literal blink of an eye. Against laser weapons, speed and altitude lose their importance. Instead, stealth must be relied upon to avoid early detection, and advanced munitions that keep aircraft far away from laser defences must be used. This all comes with several drawbacks. For example, the F-35 can only carry two weapons like the Joint Strike Missile while maintaining its own stealth. Laser turrets can take out dozens of incoming munitions each, even if the engagement starts at minimal ranges. There are of course solutions to this dilemma. SPEAR-3 standoff weapons have the best combination of anti-laser traits. Weapons like the SPEAR 3 and GBU-53/B can be carried in great numbers and keep aircraft over 100 km away from laser defences. An F-35 could carry eight of them internally, up to 16 using external hardpoints. They’re not stealthy weapons but they’re not easy to detect either, which might let them slip closer to the laser turrets.  Let’s estimate how many SPEAR 3s a powerful laser could intercept. Amateur analysis suggests the radar cross-section of a SPEAR 3 is 0.03 m^2 frontally, compared to a clean-configuration F-35 that comes as low as 0.005 m^2. If an air defence radar can detect regular aircraft with 4 m^2 radar cross-section at a distance of 300 km, then it can detect the tiny SPEAR 3s at 300 km x (0.03 / 4)^0.25 = 88.3 km. They would be approaching at perhaps 800 km/h, giving the lasers 6.6 minutes to engage them. At 88.3 km, a 1 MW beam would deliver a crippling 1-10 kJ/cm^2 blow to each SPEAR 3 in 0.06 - 0.6 seconds. As they approach, the time to destruction decreases quadratically. So again, we are in a regime where the target switching delay dominates, meaning each laser turret with 1 second of switching time can intercept upwards of 300 missiles. If the SPEAR 3s are ordered to stay low, skim the ground and pop-up on radar just 20 km from their target, losing external guidance and sight of their target on their way, then the lasers would only have 1.5 minutes to intercept them, reducing the number destroyed to around 90 per laser turret.  In practical terms, this means it takes 12 F-35s loaded exclusively with internal air-to-ground weapons to get past one 1 MW turret in the best scenario, or 38+ in a more typical engagement.   Notional rendering of the next-generation F-47. Near-future stealth craft, like the F-47 with bigger internal bays, might carry 16 upgraded small weapons that could approach even closer before being fired upon. The weapons themselves might be very stealthy, detectable only from 10 km away. Under these constraints, a 1 MW turret would destroy only 45 missiles, which can be delivered by three F-47s, or one F-47 leading a couple of YFQ-42/44 drones..  How would air warfare adapt? Militaries are excited about the possibility of lasers countering drone swarms. The laser defenders can specialize themselves. The 1 MW beam focused by 1m mirror is very dangerous to flying targets out to hundreds of kilometers, but it is overkill at shorter distances and is mostly constrained by target switching time against large numbers of projectiles. Alongside the main 1 MW lasers, miniature turrets with smaller mirrors and reduced beam power can be installed. A 250 kW beam at 532 nm wavelength, focused by a 0.5 m diameter mirror, will have a spot diameter of 10 cm (1.5x the diffraction limit) at 50 km distance. The intensity will be 31.8 MW/m^2 or 3.1 kW/cm^2. That means it can defeat flying targets (with 1-10 kJ/cm^2) within 0.32 - 3.2 seconds at 50 km, down to 0.051 - 0.51 seconds at 20 km. Assuming it retains a 1 second target switching time, this turret would be capable of defeating around 170 targets with 10 kJ/cm^2 hardness starting from 50 km away, down to 90 targets from 20 km away. And, it would be around half the cost of a 1 MW 1m turret. In other words, spending $20 million on one big megawatt turret plus two small 250 kW turrets would create a defence worth at least 270 low-flying stealthy targets, compared to just 180 from two megawatt turrets. While the smaller turrets swat away hundreds of incoming missiles, the megawatt turret can keep watch for the launch platform… literally. NASAMS electro-optical sensor for air defence. A 1 meter diameter mirror on a fast moving, accurate mount is actually an awesome telescope. It would have 2-3x the resolution of regular electro-optical and infrared detection systems and 4-9x the light collecting area, supplemented by an integrated adaptive optics system to get rid of atmospheric blur. Just using the main laser mirror as a passive telescope means it can become a very effective long-ranged sensor that does not tip off a target, unlike radar. Even better, it can be turned into a giant searchlight.  Scanning the sky with a low-intensity beam would be an interesting way to turn a laser turret into an active sensor that counters stealth. It would be a 1 megawatt ‘searchlight’ that helps contrast stealth aircraft against their background. Its turret would spin fast enough to cover the entire sky every few seconds, and it could focus its beam onto distant points of interest (acting like a LIDAR) or even poke through clouds to investigate them.  And then what? The Aero-adaptive Aero-optic Beam Control test aboard an AFRL jet.  As mentioned before, a stealthy aircraft with long ranged weaponry would be ideal. Future adaptations would push these advantages further. A jet attacker in a theater where megawatt lasers are present would want to go on prolonged flights while staying very low to the ground. Supersonic speed and maneuverability don’t matter against lightspeed beams, so a subsonic turbofan-propelled design with great endurance and even greater payload capacity is better. Ideally, it can launch its many weapons without ever exposing itself to enemy sensors. However this requires that the precise location of its targets already be known, meaning external information gathering is necessary.  Reconnaissance can be conducted by drones, but these cannot loiter above the battlefield like they do today when lasers can take them down on sight. Today’s militaries are acutely aware of the threat of small disposable drones too, so they would bring along sensors that can effectively find them and target them with laser beams, such as short-wave radars. Take out the eyes! That leaves satellites orbiting overhead and old-school on-the-ground scouting. Low orbit observation satellites, especially the smaller and cheaper kind that fill mega-constellations, would be totally vulnerable to big lasers firing up at them. A 1 MW beam could clear out all satellites it can see out to hundreds of kilometers in altitude: it can produce a 0.8 m diameter spot at 800 km, enough for an intensity of 1.93 MW/m^2 or 193 W/cm^2. That would achieve a 1 kJ/cm^2 damage threshold in a little over 5 seconds. Medium altitude (2000 km+) or geostationary (35,786 km) satellites would be safe, but they have reduced availability (fewer in number, fewer latitudes covered and slower orbits) and either lower resolution or much higher cost.   US Marines training to use JTAC-LTD to find and designate targets. ‘Force recon’ using specialized troops and ground assets like UK’s Ajax or the Chenowth Advanced Light Strike Vehicle would remain effective. A future laser-hunting party. A major difference from today is that they cannot use simple laser designators to point out targets to an incoming wave of missiles; laser warning systems (which already come standard on tanks and helicopters) would immediately warn their targets and reveal the designators’ location. They’d have to transmit passively-collected information on the targets, which means electronic warfare activity, especially broadband jamming, can determine if that information gets out and an attack is successful.  If neither satellite nor ground reconnaissance is available, then aircraft have expose themselves to potential detection to designate targets for their weapons using onboard sensors. Thankfully, they might only need a short ‘glimpse’ to do this. We could imagine very smart cruise missiles that identify their own targets, retain stealth all the way to them, then release massed submunition attacks, as a perfect munition in a laser-interceptor environment. Then attacks won’t need to rely on much reconnaissance. Effects of cluster bomb strike when low accuracy is ... unquestioned. But, this blurs the line with autonomous weapons, can have the downside of unintended or collateral damage, and we’d still expect them to remain an expensive limited option in the future.      What about lasers ON airplanes? F-16 with a Lockheed Martin laser weapon pod. If laser generating equipment continues to get lighter and more powerful, then large lasers can be mounted on aircraft. There are already plans to install laser weapon pods on jet fighters like the F-16 or F-15. Laser pod for the F-15 from General Atomics. What could be a Self-Protect High-Energy Laser Demonstrator pod for the F-15. Even the F-35 had an upgrade path to equip it with a laser weapon that would fit inside the F-35B’s lift fan chamber; the engine shaft (with 20 MW available) would turn an alternator to generate enough electricity to run a 100 kW solid-state laser. General Atomic recently revealed plans for a 25 kW laser pod to be carried by the MQ-9B Skyguardian drone. They could even be an evolution of Direct Infrared Countermeasure systems that shine lasers at the IR seekers of aircraft and missiles. Add more and more power until they are destroying instead of merely blinding their targets. DIRCM systems already come with miniature turrets. Lasers aboard jet fighters would be limited foremost by volume, weight and cooling capacity. They’re unlikely to grow to the same scale as ground-based lasers, so flying megawatt lasers are further in the future. They might still reach the 100 kW scale. 100 kW of laser light would first serve as an electronic warfare tool: it would dazzle sensors trying to lock on to the flier and delay the 1 MW that could take it down. Is it enough to  defeat (hard-kill) laser turrets on the ground with counter-battery fire? A 1 MW laser subjects its own 1m mirror to 127 W/cm^2. If it is not blemish-free, that light will be absorbed as heat instead of reflected. The “Laser Induced Damage Threshold” for mirrors, which is the beam intensity sufficient to destroy the mirror surface, is around 10 kW/cm^2 against 535 nm light (half of the LIDT against 1070 nm, as listed). LIDT values, that can rise higher with better coating. A 100 kW laser with a 532 nm wavelength, focused by a 0.5m diameter mirror at 1.5x the diffraction limit, can produce a spot with that intensity by firing from within 22 km. Such an attack would burn and crack the turrets’ mirrors, making them unable to handle their own 1 MW beams without exploding into pieces. The trouble is that this is a relatively short distance where a counter-counter-attack by an unaffected laser turret would destroy the 100 kW platform within milliseconds. Only one laser turret can be disabled at a time, and expensive stealth jets do not want to enter a numbers contest against $10m turrets over who can let loose the most beams and the most mirrors.  Disabling strikes on laser turrets would therefore have to be conducted by a ground-skimming airplane (or helicopter!) that could quickly pop up over the horizon from that distance, or a very stealthy one could simply approach that far without being detected. Or, a sort of very expensive missile-drone is sent to accompany other long-range missiles to respond to laser interception with its own laser. It would be the direct energy weapon equivalent of a jammer mounted on a missile, an example of which is the SPEAR-EW with a jammer in its nose. Each part of this of electronic attack against enemy air defences could have a DEW counterpart. Immediately, you should think that laser turrets could be equipped with shutters that protect their mirror when they are not firing. With shutters in play, a 1 MW turret will win a damage threshold contest against a 100 kW flying laser. A laser turret, but with armored doors that close. However, the flying laser could simply try to hide among the swarm of other missiles and wait for the laser turrets to open their shutters and start burning down other targets before firing in response. It’s unclear how the use of pulsed lasers would affect the situation, as the LIDT of typical mirrors against such beams is merely 20 J/cm^2. Delivered from 20 km away through a 4 cm spot, that’s a total pulse energy of 260 J. From 100 km away, it’s 6.5 kJ. It’s unknown if aircraft could carry pulsed lasers with that performance in the next 20 years. Lasers add a whole other level of complexity to air-to-air engagements. Aircraft equipped with powerful lasers can shoot down missiles fired at them, especially from long range. At shorter distances, aircraft equipped with 100 kW lasers become lethal to each other. Northrop Grumman depiction of a laser-armed sixth generation fighter. Nations with large military budgets that can install lasers on their aircraft soonest would have a huge advantage over every other air force, as a jet that can shoot down incoming missiles and then approach for a direct-fire kill that ignores most air combat kinematics (altitude, speed, relative position) would dominate opponents without a laser. Even after lasers arrive, the more powerful beam focused by the largest mirror would outrange opponents in a head-to-head engagement. But between peer opponents, laser weapons would lead to stalemates or suicidal attacks. So, aircraft would try to exploit the terrain below. Being unable to reasonably armor themselves, they can only use solid ground as protection.  Skilled pilots would be able to hide in depressions, hug mountains and pop out for lightning-quick laser strikes or to launch a short-ranged missile that curves around cover to find its target in seconds. Funnily enough, the best aircraft at this sort of game is a helicopter. It can hover behind cover indefinitely, maneuver in all directions to deny enemy fire and only needs to expose a mirror mounted on its rotor mast to retaliate. A helicopter only needs to expose a mast-mounted laser to both see and fire at targets from behind terrain cover. Another interesting outcome is that large lumbering planes, such as the Boeing E-767 or Beriev A-50, that are thought to be increasingly at risk today from ultra-long-range ‘AWACS killer’ air-to-air missiles such as the AIM-174B or PL-17, would flip the situation once powerful lasers become available. The Airborne Laser Laboratory mounted on an NKC-135A. They can shoot down long range missiles effectively, and out-range any smaller plane with direct laser fire. That raises a defensive net around large military aircraft that may be dozens of kilometers wide. The failed ancestor of this approach is the Boeing YAL-1, which had a 1-2 MW chemical 1315 nm wavelength COIL with a 1.57 m diameter mirror.  The Boeing YAL-1 first flew in 2002 and was cancelled in 2014. Should have picked a better wavelength! Because of their affordability and effectiveness, megawatt lasers for air defence would mean most nations, and even non-national military groups, could make air strikes a very complicated and expensive affair. Modern militaries that have historically relied on the strength of their air forces will be the most affected, as they’d quickly find their hundreds of 4th generation jets (expected to operate until 2050+) and thousands of short-ranged missiles and bombs ineffective against defended sites. Their ability to deliver air strikes will have to be rebuilt using next-generation stealth craft, a slow and expensive process at best. There’d be diplomatic consequences in the meantime: a US Carrier Air Group sent sailing down the Red Sea becomes a much less potent message to surrounding nations when they can add megawatt lasers to their air defences for a few tens of millions of dollars.

Let’s talk about climate change and life on Earth. Not anthropogenic climate change – but long term natural changes in the Earth’s environment due to stellar evolution. Eventually, as our sun burns through its fuel, it will go through changes. It will begin to grow, becoming a red giant that will engulf and incinerate the […] The post End of Life on Earth first appeared on NeuroLogica Blog.

Slight changes in the number, shape, efficiency and interconnectedness of organelles in the cells of flight muscles provide extra energy for birds’ continent-spanning feats. The post ‘Turbocharged’ Mitochondria Power Birds’ Epic Migratory Journeys first appeared on Quanta Magazine

Having shut down its last remaining nuclear plant Saturday, Taiwan is working to secure new imports of natural gas. Read more on E360 →