Wednesday, May 20, 2015

AFRL Direct to Airborne Laser >100 kW Weapons By 2022 - HELLADS key

Laser Fighters: 100 kW Weapons By 2022
“Air applications actually can be the most challenging,” said AFRL laser guru David Hardy. (His formal title is “Director, Directed Energy Directorate” — yes, really, he says with an apologetic smile). “On a ship, I’m probably going to have more SWAP [Size Weight And Power] than I’m going to have on an aircraft,” Hardy said. What’s more, he went on, “aircraft tend to shake more than a ship does: A ship rolls, but it doesn’t vibrate as much.” Vibration is hard on any complex machinery, but it’s especially problematic for a laser, which has to hold its beam steady enough to burn through a single spot on the target.

“A laser is basically a heating device,” Hardy said. “It heats up something. It melts holes in it. That’s what we do.” But it takes a lot of technology to get that hot spot on target, especially when fired from a flying platform. While the military has abandoned the bulky chemical lasers used on the Airborne Laser program, the experience of building ABL taught valuable lessons that still apply to the more compact electrically-powered lasers of today, Hardy told me. “Making ABL work was not just fitting the laser in: It was building the beam control system, it was building the pointing system, it was building the targeting,” Hardy said. “We learned a lot from that.”

 Another crucial evolutionary step is the General Atomics HELLADS laser, which will soon shift from a DARPA experiment to a DARPA-Air Force Research Lab joint venture. “That was a major investment on the part of DARPA,” Hardy said. “It’s the first time anybody’s shown you can make a 150-kW-class electric laser.”(The exact power output of HELLADS isn’t published, and many details are classified). The whole point of HELLADS was to build a high-power laser weapon small enough that it could fit on an aircraft, although it’s never actually been installed in one. So while HELLADS is technically a ground-based weapon, it generates a lot of power in a compact package, making it “the existence proof that we can really make these electric lasers work in the greater-than-100-kw regime, in a reasonable SWAP [Size Weight And Power].”
“We believe [that] in the next decade we’ll have systems that routinely deliver over 100 kw,” Hardy told me. “Exactly how many hundreds of kilowatts we don’t know.”

Missile defense is our biggest interest,” Hardy told me, just as it is for the Navy and Army laser programs. “But we’re also interested in the offensive capability they provide, because…as long as you have jet fuel that can be converted into electricity to feed the laser, I can keep firing the weapon.”
A typical modern fighter like the F-16 can carry at most six air-to-air missiles. Shoot six times, hit or miss, and it’s back to base to re-arm. By contrast, said Gunzinger, a laser-armed aircraft could just head back to the tanker. “Instead of landing to reload, air refueling would ‘reload’ [laser]-equipped aircraft in flight,” he said. They could keep fighting until the pilot couldn’t take it any more — or, if unmanned, for longer than any human could endure.
“There are several developmental lasers, including HELLADS, that are making great progress” towards making a weapon compact enough for an aircraft, Gunzinger told me. “Aircraft-based laser weapons could be a near-term reality.”
One of the Air Force’s leading futurists, retired Lt. Gen. Dave Deptula, was even more enthusiastic about the possibilities for airborne lasers — and, someday, spaceborne ones. In the near term, he told me, the place to start is probably short-ranged defensive systems: Instead of trying to overcome the power, focus, and atmospheric distortion problems required to strike targets far away, he said, you let the enemy come to you. But laser’s long term potential lies at long range, and aerospace platforms are the way to get there.
Lasers are just intense beams of light, after all. They get attenuated by the atmosphere and can’t fire indirectly at targets beyond the horizon the way a missile or artillery shell can. The higher the laser’s altitude, the farther it can shoot and the less atmosphere is getting in the way. This is where Air Force laser weapons have a potential that ship- or ground-based lasers can’t match.
“You can just imagine the kinds of advantages there are when you free yourself from the atmosphere,” Deptula told me. Beyond firing from high-altitude aircraft, he said, “there are some enormous opportunities here to use lasers in space or from space,” for example to shoot down enemy aircraft or ballistic missiles from above. Current international treaties prevent that, he acknowledged, and “we don’t want to weaponize space, but guess what: it’s gonna happen — so we need to be prepared to operate in space and from space.”

General Atomics' New Laser Weapon Ready for Field Testing - Times of San Diego
General Atomics Aeronautical Systems announced Friday that its lightweight, tactical laser weapon is ready for live-fire tests at the White Sands Missile Range in New Mexico.
The 150-kilowatt high-energy liquid laser, or HELLADS, is designed to be used against incoming rockets, artillery shells and mortar rounds.

The goal of the High Energy Liquid Laser Area Defense System (HELLADS) program is to develop a high-energy laser weapon system (150 kW) with an order of magnitude reduction in weight compared to existing laser systems.
The HELLADS program has completed the design and demonstration of a revolutionary subscale high-energy laser that supports the goal of a lightweight and compact high-energy laser weapon system.  An objective unit cell laser module with integrated power and thermal management is being designed and fabricated and will demonstrate an output power of >34 kW.  A test cell that represents one-half of the unit cell laser has been fabricated and used to characterize system losses and diode performance and reliability. The test cell is being expanded to a unit cell. Based on the results of the unit cell demonstration, additional laser modules will be fabricated to produce a 150 kW laser that will be demonstrated in a laboratory environment. The 150 kW laser then will be integrated with an existing beam control capability to produce a laser weapon system demonstrator. The capability to shoot down tactical targets such as surface-to-air missiles and rockets will be demonstrated.
Features/Benefits:
  • Lightweight and compact
  • Increased engagement range
  • Counters tactical targets

 Background/Related

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