Operational deployment of airborne directed-energy weapons is finally drawing near after many years of research. Flight testing for solid-state high-energy laser systems designed to mount on aircraft, including fighter jets and combat helicopters, will ramp up into the early 2020s.

Attempts to integrate laser weapon systems on aircraft date back to the 1970s, when the U.S. Air Force Weapons Laboratory converted a KC-135A into the Airborne Laser Laboratory (ALL). Flight tests of the modified aircraft began in January 1975 and continued for eight years. The ALL was a success, shooting down several missiles and drones, but was retired in 1984.

Renewed interest began in 1996 when the U.S. Air Force kicked off the Airborne Laser program. The initiative resulted in a modified 747-400F aircraft mounted with a chemical oxygen iodine laser. Although the weapon system successfully destroyed a missile in flight during testing, the program’s costs were ultimately deemed too high, and it was cancelled in December 2011.

Yet the operational capabilities promised by airborne high-energy laser weapon systems has sustained continued interest in their development.

Self-Protect High-Energy Laser Demonstrator

Concept art of a high-energy laser weapon system mounted on a fighter jet. Lockheed Martin is developing the laser under a contract with the U.S. Air Force Research Laboratory. Source: Air Force Research LabConcept art of a high-energy laser weapon system mounted on a fighter jet. Lockheed Martin is developing the laser under a contract with the U.S. Air Force Research Laboratory. Source: Air Force Research Lab

In November of last year, Lockheed Martin was awarded a $26.3 million contract by the U.S. Air Force Research Laboratory (AFRL) to develop a high-power fiber laser for flight-testing on a fighter jet by 2021. The laser, part of AFRL’s Self-protect High-Energy Laser Demonstrator (SHiELD) program, is intended to defend aircraft from air-to-air and surface-to-air missiles.

Directed-energy weapons have been tested before on ground vehicles, but integrating them in a compact, lightweight package for installation on aircraft is a unique challenge with demanding size, weight, and power constraints.

“Earlier this year, we delivered a 60 kW-class laser to be installed on a U.S. Army ground vehicle. It's a completely new and different challenge to get a laser system into a smaller, airborne test platform. It's exciting to see this technology mature enough to embed in an aircraft,” said Dr. Rob Afzal, senior fellow of laser weapon systems at Lockheed Martin, in a press release. “The development of high power laser systems like SHiELD show laser weapon system technologies are becoming real. The technologies are ready to be produced, tested and deployed on aircraft, ground vehicles and ships.”

Lockheed’s laser is one of three subsystems under SHiELD. Known as Laser Advancements for Next-generation Compact Environments (LANCE), the high energy laser will be capable of disabling enemy targets. LANCE will be powered and cooled by a second subsystem developed by Boeing called Laser Pod Research & Development (LPRD). The final subsystem is SHiELD Turret Research in Aero Effects (STRAFE), a beam control system that will aim the laser at the target. STRAFE is in development at Northrop Grumman.

Low-Power Laser Demonstrator

The U.S. Missile Defense Agency (MDA) is also interested in laser weapons. In June 2017, the MDA began considering acquisition of an unmanned aerial vehicle (UAV) capable of intercepting and disabling intercontinental ballistic missiles (ICBMs). The MDA Advanced Technology Directorate’s ultimate goal is a capability to destroy ICBMs during their boost phase using a high-energy laser weapon mounted on a long range UAV capable of flying at high altitudes.

The first step toward that goal will be development of enabling technologies under the MDA’s Low-power Laser Demonstrator (LPLD) program. To kick off Phase I of the project, the MDA awarded funding to three contractors last year, including $9.4 million to Lockheed Martin on October 5, $8.8 million to General Atomics on November 6, and $9 million to Boeing on December 8.

The first phase system design portion of the project will be followed by a build and test round to verify laser beam control and stability. A flight test is expected by 2020 with beam stability testing the following year.

The demonstrator project is expected to provide valuable insight into methods of aiming, steadying, and focusing a UAV-mounted laser to destroy an ICBM during its boost phase.

Rotary Wing Lasers

Fighter jets and drones are not the only aircraft being outfitted with directed-energy weapons. In September 2017, a high energy laser mounted on an Apache AH-64 helicopter was test fired at White Sands Missile Range in New Mexico. The test demonstrated successful target acquisition and engagement with a laser weapon mounted on a helicopter for the first time over a wide range of flight regimes.

High energy lasers mounted on Apache helicopters were tested by Raytheon and U.S. Special Operations Command. Credit: RaytheonHigh energy lasers mounted on Apache helicopters were tested by Raytheon and U.S. Special Operations Command. Credit: Raytheon

“Raytheon and the U.S. Army, in collaboration with the U.S. Special Operations Command, completed a successful flight test of a high-energy laser system aboard an Apache helicopter,” said Thomas A. Kennedy, CEO of Raytheon, in an earnings call last year. “The demonstration marks the first time that a fully integrated laser system successfully engaged and fired on a target from a rotary wing aircraft.”

The weapon system shot a ground target at a slant range of 1.4 km (0.87 miles). Target acquisition and beam control was accomplished by hooking the laser up to a variant of the Multi-Spectral Targeting System electro-optical, infrared sensor.

Raytheon mounted the laser on a helicopter as opposed to another type of aircraft in order to demonstrate its capabilities in tough operating conditions.

“Why a helicopter?” said Kennedy. “Well, a helicopter has one of the worst vibration environments that you'd have to be in, in terms of using a high-energy laser system. So we really wanted to stress our systems and its capabilities and show that that capability – the design that we had -- could withstand the high vibration environment of a helicopter.”

Rotor downwash, dust and vibration were all factors affecting the test, and data gathered will inform design decisions for future high-energy laser systems.

A number of additional airborne directed-energy weapons technology development projects are under way. The Air Force Special Operations Command plans to test laser weapons on its AC-130 gunships in 2018. And the U.S. Defense Advanced Research Projects Agency (DARPA) is funding programs such as Project Endurance to develop laser weapons to defend aircraft from missiles, as well as a project known as Efficient Ultra-Compact Laser Integrated Devices (EUCLID) to develop high-power fiber laser diode modules to power directed-energy weapons on combat aircraft and land vehicles.

With substantial ongoing research and development efforts driving maturation of the technology, the era of operational airborne high-energy laser weapon systems may soon arrive.