In H.G. Wells' seminal 1898 science fiction novel "The War of the Worlds," the invading Martians use a "heat ray" to vaporize their enemies.
Now, more than 100 years later, directed energy weapons are a reality and the military is looking to expand their capabilities to a greater battlefield role.
While the Navy is already testing a ship-based laser in the Persian Gulf, Air Force leaders are looking to mount the weapons on AC-130 gunships and, eventually, on fighters like the F-22 and F-35.
Speaking Sept. 15 at the annual Air Force Association Air and Space Conference, Gen. Hawk Carlisle, the leader of Air Combat Command, said he expects the service will begin mounting directed energy weapons onto aircraft within the next few years.
"Everybody thinks you have a tendency to talk about high-powered microwaves and lasers and it's kind of science fiction," Carlisle said. "But this is a reality. … I believe that we will have a directed energy capability in a pod that can be mounted on a fighter aircraft very soon as well."
Carlisle said the technology will "change the game."
"Imagine your ability to defeat an enemy surface-to-air capability with a directed energy weapon so you can penetrate an anti-access aerial denial environment," he said, adding that the U.S. could develop the systems to protect its own airspace as well.
Experts said they expect lasers to be mounted on fighters starting sometime between 2020 and 2025. But smaller craft could carry them sooner. Defense contractor General Atomics announced earlier this year that its laser system had successfully completed testing, and could be mounted on the company's MQ-1 Predator drones by 2018.
Lt. Gen. Bradley Heithold, the leader of Air Force Special Operations Command, said AFSOC is already working to mount a laser weapon system on an AC-130W, with plans to modify eight more.
"I want a high energy laser on an AC-130J gunship by the close of this decade," he told the AFA conference. "This isn't Star Wars stuff, folks. The technology is ripe for doing this. … I've got the space, I've got the weight, and I've got the power."
Directed energy weapons are one of the Air Force's top research priorities, and could provide a wide range of effects for war fighters and commanders. The Pentagon has been trying to develop high-powered 150-kilowatt lasers, while making the systems smaller and lighter.
Lasers have a greater magazine than any other weapon system, with a battery able to store thousands — if not more — of shots. The systems are also relatively inexpensive to fire, costing only the electricity required to run the electronics.
High-power microwaves can also be mounted on aircraft, and provide a range of capabilities including knocking out power grids, disrupting electronics or stopping anti-air weapons from acquiring a target lock.
Those are some of the capabilities Heithold said he wants for missions.
The first priority is to protect the aircraft by utilizing lasers to shoot down incoming missiles — the same capability the Navy is testing.
"What we want to do is first put a high energy laser on an AC-130 to defend the aircraft," Heithold said. "We can find the missile coming at me and zap it. … Let's get into a defensive capability that can ensure that I can fight my way to the target, I can fight on the target, and I can fight my way off the target."
After that, the lasers should be focused on the offensive side of operations, the general said.
He recalled the 1989 operation to capture Panamanian leader Manuel Noriega, where four Navy SEALs died while destroying Noriega's boat and plane to prevent his escape.
"Wouldn't it have been nice had we had a high energy laser on an AC-130 that would have simply zapped some point on that airplane?" Heithold said. "Disable the aircraft and nobody knows it happened until they go to use it, because nobody heard anything and nobody saw anything? You haven't spooked anybody, you've simply disabled the aircraft."
In addition to disabling and crippling enemy capabilities, lasers can be powered up for kinetic strikes, such as destroying vehicles. And some experts have noted they're likely to reduce the possibility of civilian casualties and collateral damage as the weapons can be fired with pinpoint accuracy.
"We are a service that was born out of technology," Carlisle said. "We need the best technology on the planet."
"Directed energy weapons is an area we're headed toward, and we're going there at a fairly good pace," he said. "I actually think it's a lot closer than a lot of people think it is."