WASHINGTON — The Defense Department’s top technology expert now believes using airborne, directed-energy weapons for missile defense is unlikely to work, and that it’s not worth spending research and development funds on the effort.

“I’m extremely skeptical that we can put a large laser on an aircraft and use it to shoot down an adversary missile, even from fairly close,” Mike Griffin, undersecretary of defense for research and engineering, said Wednesday on a call arranged by the Washington Space Business Roundtable.

“It has been done as an experiment, but as a weapon system — to equip an airplane with the kinds of lasers we think necessary, in terms of their power level, and all their support requirements, and get the airplane to altitudes where atmospheric turbulence can be mitigated appropriately — that combination of things doesn’t go on one platform.”

“So I’m just extremely skeptical of that,” he added. ”So we’re not spending money on [and] we’re not investing in airborne platforms for shooting down adversary missiles.”

Griffin’s comments would seem to reflect a change from the Missile Defense Review, a major policy document released in January 2019 that he helped create. The MDR expressly called for investments to test the idea of putting laser weapons on airborne drones, which could loiter around a launch site to take out a missile in its early boost phase.

Griffin claimed in his January 2018 confirmation hearing that airborne, directed-energy weapons for missile defense was “very feasible,” saying: “It was feasible many years ago to do it. What we have lacked in the missile defense arena until recently was the will; not the technology, not the means.”

The idea of using airborne, directed-energy systems to intercept ballistic missiles goes back a decade, most notably to the Air Force’s Airborne Laser program, which ran a successful test in 2010 before being discontinued. There are a number of directed-energy projects that are ship- or ground-based currently underway within the Defense department, but Griffin did not comment on them.

Tom Karako, an expert on missile defense issues with the Center for Strategic and International Studies, believes Griffin’s comments are a “marked change” from what was in the MDR. But, he noted, Griffin’s comments are “likely very focused on the near term. In other words, he’s explaining that they need more R&D investment now, not quite ready for prototyping and fielding.”

Griffin did note “there are applications for space platforms that could well be quite productive” when it comes to directed-energy weapons for destroying enemy missiles. And he stressed that his organization, the Office of the Under Secretary of Defense for Research and Engineering, is “certainly not” giving up on directed energy, even as it recalibrates the projects on which it’s focused.

On Tuesday, Mark Lewis, one of Griffin’s main deputies, described the office’s ongoing efforts to develop directed-energy systems as attempts to add capabilities, not mirror existing efforts.

“The key is they’re not going to be replacing things we can already do with kinetic weapons. If the gun already does something and it does it better than the laser, there’s no point in the laser or the microwave system,” Lewis said, adding that counter-drone systems are an area of high potential for laser weapons.

Said Karako: "The understandable caution about operational requirements for more stressing, higher-end missions should not preclude progress for lower ones, including counter-UAS and [counter-rocket, artillery and mortar]” capabilities.

Griffin on Wednesday emphasized that his office is trying to ensure laser technology is applicable to the end user.

“One of the things that in R&E we are focusing on, and I think frankly is well overdue (and some of the reason why it’s overdue is my fault), but we have not invested enough on understanding lethality and different modes of lethality for directed energy,” Griffin said.

“We’ve not invested enough in the operational studies that, you know, if I gave a war fighter a weapon of X number of kilowatts, you know, how and in what circumstances could you use it, and where is it better than a kinetic weapon and where is it not? The operational assessments just have not received as much attention as they should.”

Aaron Mehta was deputy editor and senior Pentagon correspondent for Defense News, covering policy, strategy and acquisition at the highest levels of the Defense Department and its international partners.

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