Tag Archives: chemical lasers

United States Military Strategy: 2015 and beyond

X-47B receiving fuel from a 707 tanke while operating in the Atlantic Test Ranges, Apr. 2015.  Image from wikipedia.

The United States [is developing]  a “third offset strategy”… It is the third time since the second world war that America has sought technological breakthroughs to offset the advantages of potential foes and reassure its friends. The first offset strategy occurred in the early 1950s, when the Soviet Union was fielding far larger conventional forces in Europe than America and its allies could hope to repel. The answer was to extend America’s lead in nuclear weapons to counter the Soviet numerical advantage—a strategy known as the “New Look”.

A second offset strategy was conceived in the mid-1970s. American military planners, reeling from the psychological defeat of the Vietnam war, recognised that the Soviet Union had managed to build an equally terrifying nuclear arsenal. They had to find another way to restore credible deterrence in Europe. Daringly, America responded by investing in a family of untried technologies aimed at destroying enemy forces well behind the front line. Precision-guided missiles, the networked battlefield, reconnaissance satellites, the Global Positioning System (GPS) and radar-beating “stealth” aircraft were among the fruits of that research…The second offset strategy,  the so-called “revolution in military affairs” was hammered home in 1991 during the first Gulf war. Iraqi military bunkers were reduced to rubble and Soviet-style armoured formations became sitting ducks. Watchful Chinese strategists, who were as shocked as their Soviet counterparts had been, were determined to learn from it.

The large lead that America enjoyed then has dwindled. Although the Pentagon has greatly refined and improved the technologies that were used in the first Gulf war, these technologies have also proliferated and become far cheaper. Colossal computational power, rapid data processing, sophisticated sensors and bandwidth—some of the components of the second offset—are all now widely available.

And America has been distracted. During 13 years of counter-insurgency and stabilisation missions in Afghanistan and Iraq, the Pentagon was more focused on churning out mine-resistant armoured cars and surveillance drones than on the kind of game-changing innovation needed to keep well ahead of military competitors. America’s combat aircraft are 28 years old, on average. Only now is the fleet being recapitalised with the expensive and only semi-stealthy F-35 Joint Strike Fighter.  China, in particular, has seized the opportunity to catch up. With a defence budget that tends to grow by more than 10% a year, it has invested in an arsenal of precision short- to medium-range ballistic and cruise missiles, submarines equipped with wake-homing torpedoes and long-range anti-ship missiles, electronic warfare, anti-satellite weapons, modern fighter jets, integrated air defences and sophisticated command, control and communications systems.

The Chinese call their objective “winning a local war in high-tech conditions”. In effect, China aims to make it too dangerous for American aircraft-carriers to operate within the so-called first island chain (thus pushing them out beyond the combat range of their tactical aircraft) and to threaten American bases in Okinawa and South Korea. American strategists call it “anti-access/area denial”, or A2/AD.  The concern for America’s allies in the region is that, as China’s military clout grows, the risks entailed in defending them from bullying or a sudden aggressive act—a grab of disputed islands to claim mineral rights, say, or a threat to Taiwan’s sovereignty—will become greater than an American president could bear. Some countries might then decide to throw in their lot with the regional hegemon.

Although China is moving exceptionally quickly, Russia too is modernising its forces after more than a decade of neglect. Increasingly, it can deploy similar systems. Iran and North Korea are building A2/AD capabilities too, albeit on a smaller scale than China. Even non-state actors such as Hizbullah in Lebanon and Islamic State in Syria and Iraq are acquiring some of the capabilities that until recently were the preserve of military powers.

Hence the need to come up with a third offset strategy.….America needs to develop new military technologies that will impose large costs on its adversaries

The programme needs to overcome at least five critical vulnerabilities.

  • The first is that carriers and other surface vessels can now be tracked and hit by missiles at ranges from the enemy’s shore which could prevent the use of their cruise missiles or their tactical aircraft without in-flight refuelling by lumbering tankers that can be picked off by hostile fighters.
  • The second is that defending close-in regional air bases from a surprise attack in the opening stages of a conflict is increasingly hard.
  • Third, aircraft operating at the limits of their combat range would struggle to identify and target mobile missile launchers.
  • Fourth, modern air defences can shoot down non-stealthy aircraft at long distances.
  • Finally, the satellites America requires for surveillance and intelligence are no longer safe from attack.

It is an alarming list. Yet America has considerable advantages…. Those advantages include unmanned systems, stealthy aircraft, undersea warfare and the complex systems engineering that is required to make everything work together.

Over the next decade or so, America will aim to field unmanned combat aircraft that are stealthy enough to penetrate the best air defences and have the range and endurance to pursue mobile targets. Because they have no human pilots, fewer are needed for training. Since they do not need to rest, they can fly more missions back to back. And small, cheaper American drones might be used to swarm enemy air defences.

Drones are widespread these days, but America has nearly two decades of experience operating them. And the new ones will be nothing like the vulnerable Predators and Reapers that have been used to kill terrorists in Yemen and Waziristan. Evolving from prototypes like the navy’s “flying wing” X-47B and the air force’s RQ-180, they will be designed to survive in the most hostile environments. The more autonomous they are, the less they will have to rely on the control systems that enemies will try to disrupt—though autonomy also raises knotty ethical and legal issues.

Some of the same technologies could be introduced to unmanned underwater vehicles. These could be used to clear mines, hunt enemy submarines in shallow waters, for spying and for resupplying manned submarines, for example, with additional missiles. They can stay dormant for long periods before being activated for reconnaissance or strike missions. Big technical challenges will have to be overcome:.. [T]he vehicles will require high-density energy packs and deep undersea communications.

Contracts will be awarded this summer for a long-range strike bomber, the first new bomber since the exotic and expensive B-2 began service two decades ago. The B-3, of which about 100 are likely to be ordered, will also have a stealthy, flying-wing design…

If surface vessels, particularly aircraft-carriers, are to remain relevant, they will need to be able to defend themselves against sustained attack from precision-guided missiles. The navy’s Aegis anti-ballistic missile-defence system is capable but expensive: each one costs $20m or so. If several of them were fired to destroy an incoming Chinese DF-21D anti-ship ballistic missile, the cost for the defenders might be ten times as much as for the attackers.

If carriers are to stay in the game, the navy will have to reverse that ratio. Hopes are being placed in two technologies: electromagnetic rail guns, which fire projectiles using electricity instead of chemical propellants at 4,500mph to the edge of space, and so-called directed-energy weapons, most likely powerful lasers. The rail guns are being developed to counter ballistic missile warheads; the lasers could protect against hypersonic cruise missiles. In trials, shots from the lasers cost only a few cents. The navy has told defence contractors that it wants to have operational rail guns within ten years.

Defending against salvoes of incoming missiles will remain tricky and depend on other technological improvements, such as compact long-range radars that can track multiple targets. Finding ways to protect communications networks, including space-based ones, against attack is another priority. Satellites can be blinded by lasers or disabled by exploding missiles. One option would be to use more robust technologies to transmit data—such as chains of high-altitude, long-endurance drones operating in relays….

As Elbridge Colby of the Centre for a New American Security argues: “The more successful the offset strategy is in extending US conventional advantages, the more attractive US adversaries will find strategies of nuclear escalation.” The enemy always gets a vote.

Weapons Technology: Who’s Afraid of America, Economist, June 13, 2015, at 57.

Laser Weapons

The notion of using energy as a weapon of war dates back at least as far as the ancient Greeks. In the late 1970s and early 1980s the idea was revived when American strategists began thinking in earnest about the technologies they would need to shoot down nuclear-armed ballistic missiles. Among the more fanciful ideas taken up by Ronald Reagan’s Strategic Defence Initiative (more commonly known as Star Wars) was the X-ray laser, which aimed to harness the energy of an atomic explosion to generate powerful laser beams….

The main appeal of using an energy beam to shoot things is that it travels at the speed of light, which means, in practice, that it will hit whatever it is aimed at. Trying to shoot down an incoming missile or warhead with a physical projectile, by contrast, is much more difficult. The guidance challenges of trying to “hit a bullet with a bullet” are enormous and are only gradually being solved using complex radars and missiles equipped with expensive sensors. A second attraction of lasers and other energy weapons is that in most cases they cannot run out of ammunition, and can keep firing for as long as they are plugged into a power source. The initial costs may be quite high, but each shot may then cost only a few dollars, compared with a price-tag of $3m or more for the latest missiles used to shoot down aircraft or other missiles.

Yet until very recently, despite the billions of dollars invested in them, military lasers have had a less than glowing record. The most famous (and expensive) experiment was America’s Airborne Laser Test Bed. This programme, which cost the Pentagon about $5 billion over more than 15 years, was an effort to cram a huge laser gun into a Boeing 747. It was intended to shoot down ballistic missiles in their “boost phase”, after their launch but before they had picked up enough speed to leave the atmosphere. The logic was that this is a particularly vulnerable time for a missile, since it is moving relatively slowly and because even minor damage to an accelerating rocket could prove fatal given the enormous stresses it is subjected to.

The airborne laser showed some promise in tests, but the programme was ignominiously zapped in 2011 by the Pentagon, which couldn’t quite work out how it would be able to keep a big, slow-moving jumbo jet airborne around the clock, deep within enemy territory, while waiting for a missile to blast off nearby.  Another laser that came close to being practical enough to use was the Tactical High Energy Laser, also known as the Nautilus laser which was designed to shoot down incoming artillery rounds. It was successfully tested in Israel, where it intercepted incoming rockets and shells, but Israel and America decided to pull the plug on it. One reason that it and the airborne laser were shot down was that military planners fell out of love with chemical lasers. These are very large and not especially portable lasers that are powered by a chemical reaction. As well as being bulky, they require large amounts of toxic and perishable chemicals, which can run out, limiting the number of shots that the laser can fire.

For the moment, the idea of shooting down big nuclear-tipped missiles with lasers has been put on hold, and proponents of laser weapons are aiming instead at more flammable targets. Much of the work in this field is now being done by the American navy….

The big trend now is to try to scale up three other sorts of laser that are far more compact than chemical lasers and can fire away merrily as long as they have power and don’t get too hot. The first sort is the fibre laser, in which the beam is generated within an optical fibre. Because this is already used in industry for welding and cutting, prices are falling, power output is increasing and reliability has been steadily improving. Industrial lasers can be turned into weapons pretty easily, simply by strapping them to a weapons mount.  But they are not very powerful. The Tactical Laser System being developed for the American navy by BAE Systems, a British firm, has an output of just 10kW, enough to run a few household kettles. Even so, it might be useful for frightening off (or burning holes in) small boats that look threatening but wouldn’t warrant a hail of machinegun fire. A slightly bigger version puts out about 33kW of power and fits neatly on existing turrets that house the rotary cannons used to shoot down incoming anti-ship missiles. It could blind optical or heat-seeking sensors on enemy missiles, or puncture small boats.  Plans are afoot to scale military fibre lasers up to about 100kW, which would enable them to shoot down small unmanned aircraft. The technology is relatively mature: a study by the Congressional Research Service (CRS), an American government-research body, (pdf) reckons it would cost around $150m to develop a prototype, and that such lasers could be in service by 2017.

The second technology being worked on is the slab laser… It would be less useful for shooting down targets flying directly at the laser because of “thermal blooming”….The Center for Strategic and Budgetary Assessments, a think-tank based in Washington, DC, argues that various sorts of solid-state lasers could be in service on American ships by 2018. It thinks that they could also be used to counter cruise missiles flying directly at a ship, using relay mirrors mounted on nearby unmanned aircraft.

To be really suitable for shooting down ballistic missiles, however, a laser with a power level of more than a megawatt would be needed. That would mean using a third technology, called a free-electron laser….

Although lasers have many advantages, in short, they also suffer from quite severe limitations. The main one is their relatively low power output. So much energy is needed to burn through the armour of a tank, for instance, that it is easier simply to fire a rocket at it. Even people do not make particularly good targets for lasers: human bodies can absorb a lot of energy before heating up substantially. (Eyes make a better target, but international conventions ban lasers designed to blind.)

A further limitation is that laser light can be absorbed or scattered by pollution, fog or smoke. Missiles or other targets can also be protected by coating them with mirrors or wrapping them with insulation. In addition, laser beams travel in a straight line, which means they are less useful than conventional artillery when shooting at something on the other side of a hill. It seems likely that laser weapons will have been deployed on ships by the end of the decade. They will have their uses, but they remain rather less fearsome than their science-fiction reputation might suggest.

Excerpts, Energy weapons: Zap, crackle and pop, Economist Technology Quarterely, Sept. 1, 2012, at 12

See also Electromagnetic Weapons