Over the past few weeks, I've published two articles about the increasing use of larger cannon aboard infantry fighting vehicles (IFV's) and armored personnel carriers (APC's):
There's an impressive amount of effort being put into the development of such weapons. Trouble is, on the horizon is another development that may make them all redundant. I refer, of course, to the vehicle-mounted laser.
Lasers have been vehicle-mounted for some years already, but in low-power configurations that might take out a small unmanned aerial vehicle (UAV) at relatively close range. They've grown steadily more capable in this role. Last year, Raytheon demonstrated a 5KW laser that's mounted on a militarized dune buggy (shown below). It's able to shoot down small UAV's at ranges of up to 5,000 meters (just over 3 miles).
Larger, more powerful lasers have shot down mortar and artillery shells in flight. This was achieved as long ago as 2002, albeit with a large, stationary laser that could not be vehicle-mounted. By 2022, it's expected that a 100KW laser will be fitted to an armored vehicle. This will be powerful enough to engage almost any target at ranges up to 5 miles (obviously, the closer the better, in terms of energy transfer sufficient to destroy the target). Its main limitation will be the guidance system, which will have to react fast enough to aim the weapon accurately at high-speed targets. I daresay that by 2030, prototype weapons of ten times that power will be available; and that's enough to threaten anything within visual range.
Lasers have the potential to revolutionize vehicular combat weapons.
Lasers have many advantages over conventional projectile weapons. A laser moves at roughly the speed of light, or 186,000 miles per second. Unlike a missile, an accurate laser beam can't be avoided. Lasers aren't affected by strong winds and can't be blown off target.
Laser weapons are invisible, operating at an optical wavelength the human eye cannot discern. They are also silent and unlike bullets and shells, do not produce miniature sonic booms. Unlike conventional weapons, which utilize a controlled explosion to generate energy, lasers have no recoil.
Lasers are also affordable. A single Griffin short-range missile costs at least $115,000. A shot from a laser costs usually costs less than a dollar, the price of the energy used. The actual laser system is more expensive ... but expect the price tag to fall as they become more common.
There's more at the link.
That being the case, there's an argument that much of the current investment in heavier cannon for light armored vehicles may be misplaced. I'm sure there'll always be a need for cannon to do things a laser can't - like shoot in arcing trajectories over hills and other obstacles, for example; the laser can only shoot in a straight line - but for vehicle-versus-vehicle combat, I think the laser is going to reign supreme as soon as it can be made powerful enough, and given an adequate power supply. There's even talk of putting one aboard combat aircraft before long.
AFRL is leading a project to develop an experimental podded solid-state laser weapon for fighter jets under the Self-protect High Energy Laser Demonstrator (SHiELD) program. The main goal there is to demonstrate a system that would be able to shoot down incoming missiles.
But if this arrangement works, it could provide a starting place for an offensive directed energy weapon. Such a system could theoretically work in both air-to-air and air-to-ground roles and could offer a host of advantages over more traditional guns, missiles, and bombs.
The inherent ability of a laser focus its beam narrowly on a particular point could improve overall accuracy and help limit collateral damage during air strikes, especially in constrained environments such as densely populated urban areas, which is itself an increasing topic of concern across the Pentagon. Depending on the exact nature of the power source, it could also offer an effectively “bottomless magazine,” allowing an aircraft to remain on station and armed for a protracted period of time, even after engaging multiple targets.
Again, more at the link.
The one aspect of a laser weapon that I haven't seen mentioned in the literature (so far) is how to protect it against the effects of electromagnetic pulse (EMP). They're not new: an EMP weapon was used in combat as early as 2003. Here's a 2013 video about a test of Boeing's CHAMP EMP weapon.
On future battlefields, we can expect EMP to be used to disable enemy electronics and reduce their effectiveness. (There are rumors that they've already been used by the USAF in Syria.) Being electronic, I daresay a laser cannon will be susceptible to such attacks too. Can it be insulated against them in some way? Can its power supply and guidance systems also be protected? That remains to be seen. If it can't be easily or fully protected, then the good old-fashioned cannon may still have a long and useful life ahead of it.