Laser weapons mounted aboard U.S. Navy ships and large trucks have already shown the power to shoot down flying drones during test trials. That early success has encouraged the U.S. military to fund a new effort to develop smaller versions of these anti-drone weapons that can fit light ground vehicles such as the military Humvee.
U.S. Marines and other troops will soon need such anti-drone defenses on battlefields. The U.S. may have pioneered the use of military drones for airstrikes and surveillance, but it's just one of 23 countries currently developing armed unmanned aircraft, according to a RAND report. The latest project by the U.S. Office of Naval Research aims to develop a 30-kilowatt laser system for military vehicles that could be ready for field testing in 2016—a huge step after years of efforts to build smaller military lasers.
"We're confident we can bring together all of these pieces in a package that's small enough to be carried on light tactical vehicles and powerful enough to counter these threats," said Brigadier General Kevin Killea, vice chief of naval research and commanding general of the Marine Corps Warfighting Laboratory, in a press release.
A small enough package would allow the lasers to be mounted aboard the Humvee and that vehicle's planned replacement, known as the Joint Light Tactical Vehicle (the vehicle commonly used by U.S. Marines and Army soldiers to get around). The Office of Naval Research recently awarded contracts to develop the laser weapons as part of the Ground-Based Air Defense Directed Energy On-the-Move (GBAD) program.
A 2013 special program announcement about GBAD described a laser weapon with a minimum output power of 25 kW and a maximum of 50 kW. Such a weapon would ideally have the ability to fire at full power for two minutes, followed by 20 minutes of recharging so its power source can reach an 80-percent state of charge.
Power for the laser would come from a combination of the high energy density batteries and vehicle's prime power generated by the engine drive shaft, said Lee Mastroianni, program manager at the Office of Naval Research. The weight of the batteries has not been set, but the Humvee's power system— on-board vehicle power system (OBVP)—adds about 180 kilograms to the total vehicle weight.
The OBVP in use now, made by DRS Technologies, can generate 30 kW of continuous power while the vehicle is stationary and the engine is running or about 10 kW on the move.
Some of the laser system's detection and tracking components have already been tested on drones "of all sizes," according to the press release. Navy researchers plan to test a 10-kW laser against more targets later this year, with the aim of building up to a 30-kW laser.
The Navy's interest in laser weapons extends across both land and sea. In April, the Office of Naval Research announced plans to install a laser weapon aboard the USS Ponce transport ship for testing in the Persian Gulf this summer. Such a laser has already proven it can destroy drones and small boats.
Jeremy Hsu has been working as a science and technology journalist in New York City since 2008. He has written on subjects as diverse as supercomputing and wearable electronics for IEEE Spectrum. When he’s not trying to wrap his head around the latest quantum computing news for Spectrum, he also contributes to a variety of publications such as Scientific American, Discover, Popular Science, and others. He is a graduate of New York University’s Science, Health & Environmental Reporting Program.