The United States. military has long wanted to mount directed energy weapons like lasers on aircraft to perform various missions currently done with old fashioned guns and missiles, but it could be up to a decade or longer before the systems are scaled to fly and powerful enough to destroy targets.

The Air Force in 2007 mounted a chemical oxygen-iodine laser aboard a Boeing [BA] 747-400 that was tested as a defense against inbound ballistic missiles. Funding was cut three years later and the program was summarily canceled. The system was found to be too complicated, potentially hazardous and cumbersome without offering much in the way of defensive capability.

An AC-130. Photo: U.S. Air Force
An AC-130. Photo: U.S. Air Force

Since then, multiple services and research agencies have begun development of lasers for multiple applications, but none have left the lab, said Keith Englander, director of engineering at the Missile Defense Agency (MDA), said July 28.

“We’ve got to get beyond piddling around with it as a science project,” Englander said at a directed energy summit hosted by the Center for Strategic and Budgetary Assessments (CSBA) outside Washington. “We need to move on into actually demonstrating the capability in the air and actually prove out that we can do with a solid state laser just what we can do with a chemical laser.

Air Force Special Operations Command (AFSOC) hit the same roadblocks when it attempted to install an “advanced tactical laser” aboard an AC-130J gunship around 2003. Testing of the system wrapped in 2009 having demonstrated little other than that chemical lasers at the time were too complex and cumbersome for airborne applications, said Rich Bagnell, who manages the self-protect high-energy laser demonstration (SHIELD) at the Air Force Research Laboratory’s directed energy directorate.

The chemical laser was found to be too large and heavy for an airborne application, he said. Just to test the system and with no other weapons payloads onboard, the aircraft needed a waiver to carry the laser and its subsystems, he said.

“We took a lot of lessons learned,” he said. “First, we need to make the laser smaller,” by a factor of 10.

As large and heavy as it was, the system still lacked sufficient power and range, he said. It also had a woefully limited magazine: five to six shots and the aircraft would have to return to base to recharge the system.

“That was unacceptable from the fires perspective as well as from the technology perspective,” he said.

Electric lasers could be a solution, he said, especially to relieve some of the reliability issues associated with potentially hazardous substances and extensive “plumbing” associated with mounting a chemical laser on an aircraft.

Bagnell took those lessons with him to the Defense Advanced Research Projects Agency (DARPA), where he is working on the high energy liquid laser air defense system (HELLADS), which has been publicly demonstrated. The system is currently at White Sands Missile Range in New Mexico where it is in the “throes of integration,” he said.

“There are a lot of lasers in development and at least three or four … that we believe can be germane to that mission in the next three years,” Bagnell said.

AFSOC is now eyeing electric solid-state laser (SSL) instead of chemically-powered ones. It envisions an AC-130 with a high-energy laser replacing either the 20 or 30mm cannon that can track and destroy targets with minimal collateral damage, according to a report by CSBA.

The Air Force continues to chase the possibility of installing a high-energy laser on large aircraft like a bomber, which could defend itself against incoming missiles while repeatedly striking ground targets with the lase or conventional weapons. It could also be deployed on aerial refueling tankers to protect them and tethered aircraft during vulnerable refueling maneuvers, the report said.

A 150-kilowatt laser could be integrated into the forward bomb bay of a B-1B bomber within five or six years, the report said.

“Given the current state of SSL technologies, though, it may not be possible to develop an SSL with an affordable unit cost in the near term that would have sufficient range and power for counter-air missions,” it said.

A longer-term goal is to develop an electric laser for use aboard small tactical aircraft. A 150-kilowatt laser would be sufficient to defeat airborne and ground targets, the report said.

SHIELD has the goal of equipping an airborne aircraft with a laser capable of destroying or at least disabling or deterring inbound ballistic missiles. The system should be complete around 2020 “once it has demonstrated at [technology readiness level] six the ability to integrate a medium-power laser in a pod that can be put on a fourth or fifth generation aircraft,” said Air Force Maj. Gen. Thomas Massiello, commander of the Air Force Research Laboratory. Event then, the power levels available in a package suitable for integration onto an aircraft would only allow for self-protection and sensor jamming, he said.

The current projection for a laser capable of destroying a missile is at least a decade, Englander said. That includes advancing various candidate technologies across the “valley of death” that separates laboratory experiments from programs ready for fielding, and identifying a platform that will be able to carry the laser high enough that the atmosphere will not interfere with the kill shot, he said.