They have been seen in science fiction for a hundred years and go by many names, heat rays, death rays, lasers, masers, phasers, disrupters and e-bombs, but they are all effectively directed energy weapons and in theory they could be the ideal weapon that works at near the speed of light and with enough energy could penetrate almost any material. But after decades of research and many large scale failures, the first directed energy weapons are being deployed by the US military and others.
So is what is the future for these exotic weapons and where might we see them and when?
Intro
In a previous video we looked at the hypersonic missiles which have the potential to be almost unstoppable with current anti-ballistic missile defence systems but I did add a little end note saying that the only thing that could potentially defeat them would be a directed energy weapon.
The reason why is because shooting down a missile be that a hypersonic one or a traditional ballistic requires firing another equally fast-moving projectile to intercept the target either with direct hit it or exploding just in front of it.
The task of getting your anti-ballistic missile to be in the right place at the right time is one of the most difficult engineering problems tackled by any country.
But what if your interceptor or your bullets could travel at almost the speed of light and with a flat trajectory. Following even a swerving hypersonic missile travelling at somewhere between Mach 7 and Mach 20 would become much easier.
Just look at the Chelyabinsk meteor, on video, it looks quite slow but it hit the top of the earth’s atmosphere and burned up travelling at around Mach 50, that’s over 61,000km/h, faster than any missile, yet you could follow its path with a handheld laser pointer from the ground.
Now that the easy part, getting a laser powerful enough to cause enough damage to destroy something maybe 100km away in a few seconds is the hard part.
Projectiles can do a lot of damage when they hit because they have a lot of mass, sub-atomic particles or light have virtually no mass so you need a huge amount of them to have any effect which in turn equates to a lot of energy and it’s the supply of this energy which is one of the biggest stumbling blocks and the reason why you won’t see handheld energy weapons anytime soon unless there is a revolution in energy storage and discharge.
One of the first practical attempts at approaching this problem was Project Nike Zeus in the 1960s which used high-speed rockets to intercept incoming ICMB’s and when they were within a few hundred feet of the target explode a nuclear warhead. The idea being that if it wasn’t disabled by the blast, the EMP or electromagnetic pulse would fry the control electronics.
But there was a problem, during the high altitude nuclear test, Hardtack Teak on the 1st August 1958, conducted in the Pacific, a 3.8 megaton device was exploded at an altitude 250,000 ft or 76km. The fireball grew very large in the near-vacuum at the top of the atmosphere and the effect of the fissionable debris injected into the ionosphere was so strong that it disrupted high-frequency communications on which the military depended over a wide area of the pacific for upto 9 hours afterwards
The electronic noise created by the gamma burst as it reacted with the air molecules to produce huge amounts of positive ions and recoil electrons also temporarily blinded the radar systems in the direction of the blast. A later nuclear test, Starfish prime in 1962 detonated a 1.4 megaton device at an altitude of 400km. That created an artificial radiation belt around the earth that latest for months and damaged not only electronics 1300km away in new Zealand but also destroyed three satellites in orbit nearby.
Although these were not true directed energy weapons, they proved that high energy electromagnetic pulses could very damaging to enemy satellites, communications, electronics and electrical supply grids. The problem was that if the were used as AMB system over home ground they would have the same effect and blind the radars tracking the ABM’s and looking for other incoming ICBM’s as well damaging military & civilian electronics in the US.
However, if the power of a nuclear blast could be focused into a beam x-rays then it could be used to shoot down ICBMs at great distances in space where there would be no atmosphere to absorb the X-rays and where they would be most susceptible before the warheads had separated.
This was one of the ideas for what would become part of the Strategic Defense Initiative or SDI, also known as Reagan’s Star Wars in the 1980s.
Laser stands for “light amplification by stimulated emission of radiation”, the first laser was built in 1960 at the Hughes Research Laboratories.
When normal light is generated from say a light bulb, it spreads out in all directions incoherently, the light waves are out of phase and usually cover a board spectrum of frequencies or colours.
In a laser, the light waves are Spatially coherent or in phase with each other, so they don’t cancel each other out and weaken the output. This allows the light stay in a highly focused beam over very long distances. They can also be temporally coherent, meaning that the light is just one frequency or one colour. Because all the light is focused into one small beam its energy is concentrated a bit like when you focus the sun with a magnifying glass.
Some of the first lasers consisted of a rod of ruby with mirrored ends and flash tube surrounding it. When the flash tube fires the light starts a process called optical pumping which raises the energy level of the atoms in the ruby rod. This then cycles between upper and lowers energy states and when this happens it’s said to be lasing.
Different light frequencies or colours carry different amounts of energy, low frequencies like radio, microwave and infrared are low energy or non-ionising radiation whereas the high-frequency Ultraviolet, X-ray and Gamma rays are high energy ionising radiation. These have enough energy to knock the electrons off of atoms to create ions and damage living cells which is why they are so dangerous to us.
Project Excalibur was a cold war research program run by the Lawrence Livermore National Laboratory to make an X-Ray laser that would be powered by a nuclear explosion and championed by the Manhatten project theoretical physicist Edward Teller and it became a major part of the Strategic Defense Initiative.
To take the example of the simple ruby laser, in an X-ray laser, the ruby rod is replaced by one or more metal rods and a nuclear bomb replaces the flash tube. If dozens of rods surround the nuclear bomb, it was theorised that each one could be aimed at a different incoming ICBM, therefore when the device detonated dozens of highly focused X-ray beams could destroy many missiles at once.
Although testing had shown that lasing of X-rays could be made to happen, the highly optimistic view the project champion Edward Teller was completely out of step with what the technology was capable of at the time, not only in the weapon design but in things like the supercomputing power required to track all the targets and aim the beams on to them in realtime.
As time went by it became clear that this was still well beyond the technology of the time and other issues with things like the metal lasing rods cast doubt on whether it could work at all and by 1992 Project Excalibur was cancelled.
This brings us on to the optical laser systems which we do know work. These have been in development since the 1960’s and range from things like lasers mounted on ships to defend against small high speed boats, to the Boeing YAL-1A airborne laser testbed. This used a laser which was mounted on the front of a Boeing 747 and was designed to use a megawatt class chemical oxygen-iodine laser to shoot down tactical ballistic missiles which are slower and lower altitude than ICMB’s.
But the problem with high powers lasers is the atmosphere itself. Over longer distances which would be needed to affect high-speed targets, turbulence in the air can refract the beam, weakening it. As the power goes beyond about 1 megajoule per cubic centimetre, the laser starts to create a plasma in the air which diffuses and scatters the beam, this is called blooming and it becomes worse if there are particles in the air such as fog, smoke, dust, rain, smog or chemicals deliberately dispersed by an enemy.
To try and minimise blooming, various techniques can be used including multiple beams, pulsed lasers, laser beam shaping, phase correction and adaptive optics but the only place where a laser can be exploited to its fullest extent is where there is no atmosphere to get in the way and that is space.
The Boeing Airbourne laser was cancelled because it would need to have been flying over the enemy territory for long periods waiting for missiles to be launched to be close enough for the laser to be effective. To cover a wide area, a fleet of these would be required to be in the air 24/7, all being targets for enemy missiles and fighters. And it wasn’t as if the laser burned a hole in the missile, all it would do is to heat up a portion of the outer skin which would then weaken it and cause the structure of the missile to fail with the stress of flying through the air. So a defence against such a laser could be as simple as a coating that reflects laser light and greatly reducing the heating effect.
This idea hasn’t been entirely dropped as it been suggested that a fleet of UAV’s could be fitted with lasers and fly at very high altitudes to achieve a similar purpose. These could be refuelled in mid-air to give them extremely long flight durations allowing them to loiter around until missiles are launched.
Other uses for lasers are handheld guns to dazzle or temporarily blind troops and more high power ones to blind the infrared heat sensors on surface to air and air to air missiles, this is one of the features of the F-35 as part of its electronic warfare system.
Other methods which have been tested include particle beam weapons which shoot a beam of high energy particles, either as ions or neutral particle beams. This method is commonplace particle accelerators like synchrotrons and cyclotrons and used in places like the Large Hadron collider at CERN.
Advanced accelerators can accelerate large heavy subatomic nuclei like iron or mercury to near light speed, these carry a lot of kinetic energy which is converted into heat when they hit the target material causing rapid superheating at the surface and ionising effects at deeper levels which could damage electronic devices in a missile for example.
In 1989 as part of the Strategic Defense Initiative, a low power neutral particle beam accelerator was successfully tested in orbit before being returned intact and is now is at the National Air and Space Museum. But to date no weapon using this technology has been deployed, partly because the power supply required and size of the magnets to make a viable weapon would be too large to make it portable.
But what have become deployable systems are ones based on high power microwaves. These have had a controversial history with systems like the Active Denial System developed by the US military which are designed to control crowds or provide perimeter security and where used in Afghanistan in 2010 to control crowds without using live fire.
These work on the same principle as a microwave oven by exciting water molecules in the skin causing them to heat up and create a burning sensation, basically to get people to move away from the area without using lethal force or causing permanent injury. As some have stated it fills in the gap between shouting and shooting.
The difference between this and a microwave oven is the frequency of the ADS is much higher at 95Ghz to the 2.45Ghz of a microwave oven. This means that it can only penetrate the top layer of skin to about 0.4mm compared to the 17mm of the lower frequency oven. The Current system ADS II, uses 100kw output to cover a wide area but can be focused on smaller areas farther away.
However, just as anyone with a microwave oven will know, if you wrap your food or yourself in a conductive material like aluminium foil or specialist electromagnetically shielded clothing, you create a faraday shield which greatly reduces the effectiveness of such a device.
But that hasn’t stopped the development of what some people call E-bombs, high power microwave systems used to destroy computers and other electronic devices. Just as was found in the nuclear tests, you can induce large electrical currents into any unshielded electrical system if you expose it to high power radio waves. Again, if you put a fork or spoon in a microwave oven you will see the sparks jumping as the metal acts as an aerial but you don’t need a continuous beam of microwaves to damage modern microelectronics. A very short pulse of microwaves, as short as 100 nanoseconds but a very high peak power up to 1GW can instantly fry the tiny transistors in modern IC’s.
The US airforce as an already deployed cruise missiles with such a system called CHAMP or Counter-Electronics High Power Microwave Advanced Missile Project. The idea is that these would be dropped from a B-52 and fly to the target area and then zap individual buildings with a focused beam of microwaves, destroying computers and electronic systems inside.
This would allow them to target buildings which are deemed a military threat such as regional headquarters but leave civilian ones like hospitals untouched. Because the high energy pulse of microwaves is very short it doesn’t have time to heat up water molecules in living tissue and cause burns and as such is no threat to the people inside the building.
Similar High Power Microwave weapons are also expected to be integrated into the F-35 and other UAVs by the mid-2020s.
Another area where this type of targeted microwave weapon is being used is against drones and drone swarms like those that attacked the Saudi oil refineries and are being used by other countries too.
With easily available commercial drones able to carry out spying operations or even carry small but deadly high explosives, using high power microwave pulses to destroy their electronics would stop them dead in their tracks and they would fall out of the sky. Even if the electronics are shielded, the GPS ariel which is the drones rely upon for guidance is still exposed. Even our old friend the lasers are being used to burn the frame of the drones causing structural failure.
Raytheon has built and tested two systems for the US army one using high power microwaves and the other using high power lasers as counter-drone weapons.
For a glimpse of the future, there are rumours of similar systems being under development using microwave or lasers combined with high-speed tracking radar that is optimised for shooting down artillery shells, mortar and rockets in flight by heating their explosive charge until they detonate.
As our technological world is now so dependent on electronic equipment, the threat from the emerging energy weapons is a very real one. An e-bomb could potentially knock out an entire city and whilst it doesn’t damage buildings and people directly, the effects would set you back to the steam age until repairs and replacements could be effected. But if you know-how electromagnetic waves work then you could build your own faraday protection just like we saw in the video.
