The drone buzzed over U.S. ground troops in southern Syria. It was big, about the size of a Predator, and it was armed.
Without warning, it fired.
The munition "hit dirt," a Pentagon spokesman later told reporters, and a U.S. aircraft shot the UAV down. But the incident, along with a similar shootdown two weeks later, are just recent examples of the threat drones pose to U.S. and allied forces around the world. As the skies fill with everything from powerful Predator-style drones to cheap quadcopters that swarm, surveil and attack, ground troops need options to fight the full range of threats in this new era of the UAV.
“Whether it’s shooting them down, jamming them or frying their electronics, we’re seeing the U.S. experiment with all these different solutions, and that’s good,” said Paul Scharre, a former U.S. Army Ranger who now studies drones as a fellow for the Center for a New American Security. “It’s very reminiscent of the early days of aerial warfare.”
And with decades of experience developing the technology that has given the U.S. and allies an advantage in the air, Raytheon is ready to meet the new mission.
PHOTONS IN FOCUS
Drones, like IEDs in the Iraq War, have given small groups a cheap way to cause severe damage.
While traditional missile-defense and anti-aircraft weapons can shoot drones down, that becomes impractical when enemies can afford to launch hundreds of them at a time.
“That’s not a cost-exchange ratio you want,” Scharre said.
One answer, then, is a weapon that costs nearly nothing to shoot. Like a laser.
High-energy lasers offer a virtually limitless supply of ammunition. As long as there’s power, a laser can fire.
“They’re very, very cheap per shot. We’re talking pennies,” said Ben Allison, a physicist who leads Raytheon's high-energy laser product line. “High-energy lasers seem to provide the promise of being the most utilitarian solution, at the most efficient cost, with the minimization of collateral effects.”
Working with a radar, sensor or spotter, a laser system would see a drone, identify it, track it and choose a weak point to attack. Then, using light particles created from electrical energy, it would focus its beam through a lens and fire. A successful laser strike would hit its target instantly and have it in a smoldering tailspin within seconds.
“Think of using a magnifying glass to burn a piece of paper,” Allison said. “What we talk about with a laser is being able to target all the thermal energy on a spot.”
Raytheon helped demonstrate a laser strike in 2014, when the company’s Phalanx system guided a laser weapon that downed a large drone in a test over the Persian Gulf.
But in the age of the tiny quadcopter, tracking will prove a major challenge. The smaller the drone, the more agile it tends to be – far more so than the missiles, fighter jets and large UAVs many radars were built to follow.
“That particular problem is something Raytheon does very well – acquire, track and maintain that precision,” Allison said.
Raytheon recently showed its advancement in laser technology in a test at White Sands Missile Range. An Apache helicopter armed with a laser used Raytheon’s Multispectral Targeting System to acquire, track and focus the beam on a stationary target. The test marked the first time anyone had done that from a helicopter.
While lasers grab headlines for their sci-fi appeal and low long-term cost, another emerging technology offers similar advantages in a different way.
A MICROWAVE LIKE NO OTHER
A laser cannon is a quick, cheap way to take down one drone at a time. But what happens when there are a few hundred on the horizon?
That’s a job for a high-powered microwave.
Using amped-up radio frequencies, it blasts out a powerful beam that fries the circuits of anything in its path.
Swarms, then, are "a perfect application," said Susan Kelly, a former U.S. Air Force captain who now manages high-powered microwave programs at Raytheon.
"With high-powered microwave, anything that's in our field of regard is going to come down," she said. "You can shoot down as many UAVs as can be physically possible in that field."
Like lasers, high-powered microwaves have what military experts call an "infinite magazine," or virtually unlimited ammunition. It runs on generators, and Kelly said a single unit could conceivably fire more than a million times.
Raytheon demonstrated its Phaser high-powered microwave system for the U.S. Army in 2013. In a test at Fort Sill, the system – developed by the company on its own dime – downed two UAVs. Raytheon is planning to demonstrate the technology again for the entire Department of Defense in the fall of 2017, this time using it against up to 60 drones – including multiple targets at a time.
High-powered microwave does come with a caveat, however. Its powerful frequencies don't discriminate between allies and enemies, meaning troops couldn't simply leave it on and use it as an anti-drone force field.
"It's one part of a larger solution," Kelly said. "If I'm an Air Force commander trying to defend a base, I'm going to want my missiles there too. I want it all."
While engineers get lasers and microwaves ready for drone battle, they’re also finding creative ways to use weapons that soldiers have had in their arsenal for years.
modern threat, meet cold-war weapon
Raytheon’s Stinger missile, first built to take out Soviet aircraft and helicopters, can now do battle against drones, thanks to a simple modification. Using a device called a proximity fuze, Stinger missiles can detonate near their target, meaning they no longer need a direct hit.
That’s a powerful counter to the elusiveness of tiny, toylike drones that can turn on a dime. In a recent U.S. Army test at Eglin Air Force Base in Florida, Stinger missiles with proximity fuzes intercepted two UAVs – an MQM170C Outlaw and a smaller unspecified model.
Stinger fires from vehicles and shoulder launchers, and it is well-known to forward-deployed gunners, said Dave Buckley, a retired U.S. Army colonel and combat veteran who now works on the Stinger program.
The modified missile gives ground troops “a lot of flexibility on that forward edge, particularly at the brigade, battalion level and below,” he said. “It gives them an organic capability – something the company commander owns. They don’t have to ask someone else. They have it right there.”
YOU HAVE TO SEE IT TO SHOOT IT
The first part of taking down a drone is knowing it’s there. And while radar does wonders for tracking aircraft and other high-flying, fast-moving objects, drones pose a challenge. Some can fly low and very slowly, and they can also hide in the blind spots that open up when radars on the ground look over the curves of the Earth.
“The farther you go out, the more of a gap there is for a drone or a UAV to take advantage of,” said Jim Bedingfield, a director of missile defense programs at Raytheon.
To solve those problems, radars can pair with aerial surveillance systems to look down and detect low-flying drones, essentially eliminating their ability to hide in the contours where a traditional ground radar can't see. Tracking more objects may also require more computer processing power – an improvement that's now possible thanks to advancements in the miniaturization of computer chips.
“We’re constantly looking to improve present systems like Sentinel and Patriot, and the ones that are in the development phase are looking to take the counter-UAV game to the next level,” Beddingfield said.
None of these technologies has to work alone. In fact, militaries may well want several in the same place, so they can choose which to use according to the size, number and function of the drones they’re fighting.
“The advantage we have over most other companies is, we do it all in the counter-UAS world,” said Bruce Grooms, a retired U.S. Navy vice admiral who now leads Navy and Marine Corps programs at Raytheon. “I don’t know of many other companies that can make that same claim.”