The Marines believe one day, a laser-armed F-35 will see the light of day. Image source: Lockheed Martin.

It's been nearly two years since we first caught wind of a new project, sponsored by the Defense Advanced Research Projects Agency (DARPA), to put laser guns on warplanes. Two years since "the Pentagon's mad scientists department" announced they had hired Lockheed Martin (LMT 5.63%) to develop a means to "counteract the effects of turbulence caused by the protrusion of a turret from an aircraft's fuselage," and permit a fighter jet to fire a laser weapon with precision.

Two years later, the U.S. military has still not given up on its dream.

Baby steps...

Last year, we updated you on the military's decision to begin installation of laser guns on Lockheed Martin AC-130 gunships by 2020. The theory then was that a 200 kilowatt laser canon wouldn't take up much more room than a standard issue M102 howitzer -- which the AC-130 is already equipped with. And the Allison engines  on the AC-130 put out plenty of juice that could power a high-energy laser. And so, with just a little rejiggering, the Air Force thought it should be possible to switch out the howitzer, and replace it with a laser cannon.

If that works out well, then the Air Force would see about shrinking the laser down in size, and perhaps putting it aboard a smaller warplane. And now we learn that the  Marine Corps is on board with this plan as well.

Followed by a giant leap

As website revealed last week, the Marine Corps has plans to install laser weapons on F-35 fighter jets -- indeed, that it is "absolutely" committed to doing so.

As with the Air Force, the Marines' initial intention is to mount laser weapons aboard large planes such as the KC-130 (an armed version  of Lockheed's C-130 Hercules, similar to the Air Force's AC-130). But "as soon as we could miniaturize them," says USMC Lt. Gen. Robert Walsh, the Corps would plan to begin installing lasers aboard F-35s, Cobra attack helicopters, and MV-22 Osprey tilt-rotor aircraft as well.

The reason: Economics.

Projectile-based weapons -- be they guns, missiles, or cannons -- imply by necessity ordnance to fire from them. That ordnance must be transported to the battlefront (which costs money), loaded aboard a plane (which costs space), and then carried in flight (which costs fuel ... which in turn costs both money and space). In contrast, a laser is powered by the airplane's own engines, and its own fuel load. While that fuel certainly costs money, it's so efficient at creating destructive energy that even today, laser weapons are estimated to cost only about "a dollar-a-shot" to operate.

And that's a whole lot cheaper than a missile.

What it means to investors

So first the Air Force, and now the Marines -- that's two-thirds of the operators of Lockheed's F-35 that are now on record and on board with the idea of arming warplanes with laser guns. (And we already know that the Navy has its own fondness for lasers). But who will be building these weapons for the military, and which companies should you be looking to invest in to profit from the transition from projectile weapons to lasers?

Lockheed Martin is the most obvious candidate. Not only is it working on laser weapons for DARPA, it also builds the plane most people are saying will be the first platform to carry them -- the world-famous C-130 Hercules -- as well as the F-35 stealth fighter that the Marines hope will be the vehicle that laser guns eventually end up on.

However, you also need to keep an eye on Boeing (BA 4.24%), which ran the Pentagon's last large-scale airborne laser project, and on Raytheon (RTN) and Northrop Grumman (NOC 0.96%) as well. Both Raytheon and Northrop partnered with Boeing on the Airborne Laser project before its cancellation in 2009.  And then there's Kratos Defense (KTOS 5.33%), a small company that's been making a lot of news in the drone space lately -- and also coordinated the Navy's effort to put a laser cannon on one of its warships.

Basically, it's hard to name a company in the defense industry today that is not actively researching laser weapons. But the place to start your research is still Lockheed Martin. With a hand in both the development of the laser gun itself, and the platform(s) it will be mounted on, Lockheed is the single company burning this candle at both ends -- in a good way.