ROME – A ship-borne laser weapon being developed for the U.K. is edging closer to achieving pinpoint accuracy, and it is all being done with mirrors.
Launched in 2017, the U.K.’s Dragonfire laser program, led by missile house MBDA, will reach a milestone this spring when team member Leonardo delivers technology to the group to ensure the beam can strike a tiny target miles away.
While QinetiQ is building the fiber-based laser itself and prime contractor MBDA is handling command-and-control and image-processing capabilities, the U.K. arm of Italian firm Leonardo is handling the so-called beam director.
“Beam director technology can sometimes be overshadowed by the system’s multi-kilowatt laser source, however, it is critical to the overall system because it facilitates the ultra-precise tracking and pointing accuracy required to generate a damage effect,” Andrew Sijan, Leonardo’s head of advanced targeting campaigns told Defense News.
“In simple terms, the challenge of a Laser Directed Energy Weapon (LDEW) system is getting maximum laser power onto an extremely precise point. This is because you need extremely high laser power density to cause a physical effect and you need to do so at long ranges,” he added.
Key to Leonardo’s work are so-called “Fast Moving Mirrors” (FMMs), known in the United States as Fast Steering Mirrors (FSMs), which are used to rapidly and precisely maintain the laser beam on target, even when the target is moving, the ship carrying the laser is moving and there is atmospheric interference in between.
“To enable this, the beam director is closely coordinated with high-resolution, fast frame rate cameras with advanced algorithms to provide feedback to the beam director, so that the mirrors can make extremely fast and precise movements to keep the beam on-target,” said Sijan.
The challenge has been to build mirrors which will not be destroyed by a laser beam which is designed to punch holes in hostile vessels or drones miles away.
“We’ve solved this with special low-absorption coating technologies and by carefully choosing the materials used in mirror construction,” said Sijian.
To get the beam director ready, Leonardo has built on experience gained working on its Miysis Directional Infrared Countermeasure system (DIRCM). Designed to be used by aircraft, DIRCM turrets fire a laser at incoming missiles to disturb their infrared homing optics.
The beam fired by Dragonfire will be far more powerful than a DIRCM, which need only dazzle not destroy. MBDA has not released data on the laser’s performance, but officials on the program reportedly believe it has world-beating power and accuracy.
While accurate target tracking will be handled with mirrors, so-called “coarse tracking” is used to turn the laser towards the target, said Sijian.
“LDEW systems are large and the beam director needs to be cued to the targets very quickly to point the laser in the direction of the target before the ultra-fine tracking provided by the FMMs takes over,” he said.
Coarse tracking will likely involve linking the system to sensors on board, including radar.
As Leonardo works on Dragonfire, it is mulling how the technology can be put on an aircraft, namely Tempest, the U.K.-led, 6th-generation future fighter the firm is partnered on.
“LDEW is one emerging technology that could offer operational advantage for Tempest,” said Kenny McCormick, Leonardo’s head of Capability – Electro-Optics.
“This includes the ability to rapidly acquire targets and direct highly-focused energy with laser precision. In contrast to conventional weapons, the number of times it can be fired is limited only by the available power source, rather than magazine size.”
He added, “Within Team Tempest, Leonardo has been working closely with BAE Systems and MBDA to assess the feasibility of an airborne LDEW capability.”
He said, “This will build upon learning generated under the Dragonfire technology demonstrator program.”
The challenge? “Reducing the Size Weight and Power (SWaP) of an LDEW system for use in the airborne domain,” he added.