By Sandra I. Erwin
A laser beam the size of a quarter fired from the back of a truck successfully shot down football-size mortar rounds and took small drones out of the sky.
In the world of directed-energy weapons, this was a milestone achievement, government and industry officials said. It happened between Nov. 18 and Dec. 10 during tests of the Army “high energy laser mobile demonstrator” at White Sands Missile Range, N.M.
Laser beams that can replace bullets and missiles have been a tantalizing prospect for decades, but the Pentagon has been less than enthusiastic. Directed-energy is what experts consider a “disruptive” technology that upsets the status quo. The notion that military forces would ditch proven kinetic weapons and take chances with light beams has made lasers a tough sell so far.
The Army tested a 10-kilowatt laser and beam director mounted on an eight-wheel 20-ton truck. It engaged more than 90 60mm mortar rounds and several unmanned aerial vehicles from less than two miles away. A surrogate radar was used to queue the laser.
The Boeing Co. is the prime contractor for the demonstration program. The Army has spent about $13 million to $20 million a year on the project since 2006. The 10-kilowatt commercial laser — packaged in a 5×4-foot box — is made by IPG Photonics in Massachusetts.
The recent tests mark a “big step in the proof of high-energy lasers,” said Terry Bauer, program manager at the Army Space and Missile Defense Command in Huntsville, Ala.
The program office has ambitious plans to build 50-kilowatt and 100-kilowatt lasers in the coming years, which, if successful, would offer the military the option of using lasers to defeat larger and faster weapons such as artillery shells and cruise missiles.
The far more powerful lasers are attainable if the Army continues to fund the program, Bauer told reporters Dec. 12 during a conference call. “They will transition to the Army in the future if the Army so desires,” Bauer said.
This latest technological victory, however, far from guarantees that laser weapons will become mainstream in the foreseeable future.
The Pentagon for decades has had a rocky relationship with laser weapons. One hitch has been the slow pace of progress in electric, or solid-state, lasers.
Lasers radiate light via different media, which can be gas, liquid or solid state. Up until recent years, only chemical lasers could achieve the level of power needed for the device to be militarily useful. Most notably, the Air Force poured billions of dollars into a megawatt-class system installed on a Boeing jet that was intended to shoot down ballistic missiles. Chemical lasers turned out to be impractical and logistically complex.
Solid-state lasers are electrically powered, which makes them attractive for compact weapon systems. But it has taken many years for electric lasers to reach the desired power levels — starting at tens of kilowatts — to build a weapon-grade system.
“The Army walked away years ago from chemical lasers due to the logistics involved,” Bauer said. “We’ve been working with the laser industry to speed up the development electric lasers,” he said. “Significant progress was achieved in the past four to five years.”
There is still a long road ahead. Is the Army ready to bring high-power lasers to the battlefield? “That’s up to the requirements people,” Bauer said, referring to the Army bureaucracy that decides what technologies will receive funding. “All we do is demonstrate the technology in hope that we transition to a program of record in the future,” Bauer said.
Under the current timeline, the Army will spend the next nine years developing and testing higher power lasers, leading up to the 100-kilowatt prototype, he said. “The demonstration plans goes through 2022. … The transition to the Army is still unknown right now.”
A 100-kilowatt laser is now the Holy Grail. It could take out a target in one-tenth of the time that the 10-kilowatt device would. “Ten kilowatts is not a power level that we consider tactically or militarily useful,” said Bauer.
The Defense Advanced Research Projects Agency, too, is financing development of a high-energy laser as an anti-aircraft weapon. Its goal is a 150-kilowatt system that would be 10 times smaller and lighter than current lasers of similar power. The prime contractor is General Atomics. The objective would be to arm tactical aircraft and surface ships. DARPA plans to test the laser next year at White Sands Missile Range, against rockets, mortars and surface-to-air missiles.
The Pentagon also is funding a program to produce a 50-kilowatt ruggedized electric laser for the Air Force and the Army. Several major defense contractors designed prototypes.
Lockheed Martin was selected to design a 60-kilowatt laser that the Army intends to install on a truck and test in fiscal year 2017. The target weapons and operational scenarios have yet to be determined, Bauer said. Lasers are serial killers, Bauer explained. A beam can only shoot one target at a time, in a serial fashion. An Army platoon, for instance, could deploy with a mix of directed-energy and conventional weapons. About three to five laser systems would be needed to support a platoon or defend a forward base in war zones.
In the recent round of Army tests, officials said, one of the significant revelations was that lasers are effective at blinding cameras and other sensors that usually are mounted on drones. Several drones were blinded and their tails disabled, which made them unstable and caused them to crash.
Michael L. Rinn, Boeing vice president for directed energy systems, said the possibilities for tactical uses of lasers are endless. “The speed of engagement, versus kinetic systems, is a huge advantage,” he said Dec. 12. “You could see them blinding the enemy’s sensors and taking out rockets, artillery, mortars and potentially aircraft. You could see them in the Navy on ships.”
Boeing in 2009 produced a 2-kilowatt fiber laser that soldiers used to detonate roadside bombs. “It opened up everybody’s thinking about directed-energy systems,” Rinn said. As the devices now reach higher power levels, “You are seeing rapid development of solid state electrical fiber lasers.”
The Army for years has been seeking a better way to defend soldiers from rockets, artillery and mortars. The 10-kilowatt lasers tests showed that directed energy is worth considering, said Rinn. Mortars travel at low velocities for short ranges in high-arching trajectories. The laser melts the high explosives in the mortar so it doesn’t explode when it hits the ground. “We turn it into a rock,” Rinn said. Rockets are tougher to defeat because of their high speed and flatter trajectory.
Rinn, like other advocates of directed-energy weapons, believes that if only the military spent more money, the technology would advance faster. “The schedule could be accelerated with additional funding,” Rinn told National Defense in October. “If there were more funding, the technology could move faster.”
Bauer cautioned that a laser is no “panacea” in the fight against rockets and artillery rounds, “but it will be a significant step up to defend soldiers.”