Military Lasers

Science fiction, written, in the movies and on TV is replete with ray guns, laser cannon and other beam weapons that do everything from stunning individuals to destroying planets. One of my favorites is from a movie I was told a bout but never saw. It is one of the asteroid strikes earth movies> The USAF straps a laser to the underside of an F15, sends the plane to its maximum altitude and destroys the asteroid. It was exciting fiction but really lousy science. Remember, you cannot get more energy out that you put in and with a laser, you won’t get out anywhere near what you put in. When you hear about some hypothetical airborne or space based laser weapon that levels cities and destroys the countryside, forget about it. It is not going to happen unless the laser is powered by a really big nuclear reactor or someone invents the power source of the Star Trek Enterprise. Before you start to worry about that happening, read about our success with controlled fusion.

In my earlier post I said that I generally agreed with One Hand Clapping’s post on military lasers. See my post from January 16. For this post, I assume you have read the link at OHC.

Military lasers generally fall into two categories: Range finding/target designating and combinations/variations, and weapons. The US military has no laser weapons today although all the services have ideas in research. A militarily effective laser weapon requires a high-energy laser (HEL) source. To date, five types of HEL have been demonstrated although two have only been prototyped at relatively low power levels.

Three of the lasers are chemical lasers. They are the deuterium-fluorine laser (DF), the hydrogen-fluorine (HF) laser and the chemical oxygen iodine laser (COIL). The Army and Navy have research programs looking at DF lasers and the AF is researching the COIL for use on their airborne laser platform. HF lasers are in the running as a space-based laser. Chemical lasers use really nasty chemicals to produce a laser beam and present a major logistics problem for ground forces.

The other two lasers are the free-electron laser (FEL) and the Solid State Laser (SSL). The FEL was to be the mainstay of the Strategic Defense Initiative’s Ground Based Laser, but the program office was unable to produce a laser of sufficient power to meet requirements. The FEL would appear to be the ideal laser for military applications in that it works from electrical power and has tunable wavelengths, but without considerable technological advances, it is too large for AF or Army applications. The SSL is currently an Army research program. Like the FEL, the SSL uses electricity to produce the laser beam. This means that the deployment logistics load would be much less for the SSL as compared to one of the chemical lasers. Also, the SSL should be relatively small possibly fitting on the back of a Humvee. Three primary challenges exist for the SSL developers; heat management in the lasing medium, diode reliability and diode cost. The Army is having success at solving all three.

One Hand Clapping says that lasers cannot defeat a massive artillery attack and he is correct. Although lasers would not be deployed as individual firing units, there appears to be no way that an army could ever have enough to defeat a mass artillery barrage such as one that North Korea could deliver. If the US is at war with a peer threat in a conventional large force on large force scenario, lasers will, at best, provide some protection for critical logistics and command, control and communication assets. Lasers will not in the next 20-30 years provide protection against or defeat a massed artillery attack, nor be an effective weapon against armor. The kill mechanisms are not there. Remember, you can only get out some of the energy you put in.

If you envision lasers defeating tanks and destroying enemy ground or sea-based weapons platforms, forget it. It is not going to happen. HEL use characteristics of the target to destroy it. Missile defense HEL will weaken the outer structure of ballistic missiles or ignite fuels. Anti-artillery HELs heat the outer skin of the projectile to set off the explosives it contains. Destroying armored vehicles is not possible since there is no mechanism the laser can interact with to destroy the armored vehicle.

HEL can and will be used to destroy small numbers of mortar and artillery rounds, various airborne weapons platforms and ballistic missiles.

NEXT: How HEL may be used by future forces.