A Boost to Missile Defense Despite Budget Cuts

Written by Tom Marlowe

The Obama administration proposed cutting spending for missile defense in fiscal year 2010, but the Missile Defense Agency (MDA) has expressed confidence in moving forward with laser-based interceptors that have been demonstrating some promise in recent months. MDA Executive Director David Altwegg particularly discussed the capabilities of the Airborne Laser (ABL) program at a press conference in May. ABL is under contract to a Boeing-led team. A key shootdown test is in on track for September as ABL already has successfully completed several advance tests.

“Shootdown right now is scheduled for September,” Altwegg declared. “And we intend to immediately conduct additional flight tests. And we’re funded at about $150 million a year to advance the technology and to conduct flight tests.” Due to previous schedule delays and other program issues, ABL is being returned to a technology demonstration program beginning in FY10.

Altwegg cautioned, “A decision, though, could be made sooner or later on the future of the program because there are operational considerations that need to be looked at in additional detail, and there’s the affordability issue.” Shootdown testing for ABL will extend to multiple targets, Altwegg added, and the Defense Department plans to run five launches against ABL in a single test.

ABL, a laser mounted on an aircraft, is designed to locate and track missiles in the boost phase of their launch. It then points and fires a high-energy laser to shoot down the missile during the boost phase.

Although Altwegg signified that MDA research would shift more into ascent-phase programs, he held out hope for several boost-phase efforts, including ABL. The military would like to intercept missiles before they can deploy any countermeasures in the ascent phase, Altwegg said, but it has started concentrating some efforts on shooting down missiles right after the boost phase in an effort to control program costs.

Because technologies currently exist that could lead to successful shootdown demonstrations for missile in ascent phase, the Pentagon decided to put more effort into development of programs that use those technologies, Altwegg noted.

“Otherwise, we believe technologies now available, not previously available, make this a more suitable, more affordable enterprise. Time will tell, and we don’t have a 10-year wait period to demonstrate. We’ll be off and running soon,” he stated.

That said, Altwegg cautioned, don’t count ABL out yet.

Chemical Laser

The September test will represent the first time ABL has been fired in the air against a launching missile, Mike Rinn, Boeing vice president and ABL program director, told MSMF, but the tests that have occurred so far over the spring and summer of 2009 have also been significant.

He attributes the success of those tests to date in advancements in the development of beam control and fire control systems. In tests on June 6 and June 13, Boeing fired the beam control/fire control tracking laser and a beacon laser, which compensates for atmospheric conditions, along with a shell, a lower-power simulation of the high-energy ABL laser.

The system successfully tracked missiles in their boost phase, giving observers confidence that they could shoot it down.

“We fired that whole system through the acquisition process against two boosting missiles and literally hit a home run,” Rinn remarked. “We were able to run through the entire acquisition sequence for both missiles automated, acquire the missile as it broke the cloud deck, and actively track it.”

Finding and tracking the missile involved putting a laser pulse to the missile and closing a track loop on it. That process happened within seconds. Then, demonstrators chose an aim point, compensated the outgoing laser beam, and fired.

The targets were not destroyed because the test involved a low-power substitute for the high-power ABL laser, Rinn stressed.

“We are about to do that” in the September test, he elaborated. “But that’s a huge step for us because now we will have to run through everything we need to acquire, track and compensate a laser beam on an accelerating, boosting target.”

These tests occur on San Nicolas Island, off the coast of California. At press time, the next test scheduled there involves an instrumented missile that will score the effectiveness of the lasers, Rinn explained. The missiles have instruments on their sides that score the results of the ABL strike against it and report that data back to base.

“At that point, we will do some high-power laser flight testing internal to the airplane where we will actually bring the laser up in the air for the first time. We are going to run that in the July time frame,” Rinn added.

In August, Boeing will change out six small optics in the front end of the ABL turret and run them through the high-power laser in some ground tests. Then the big test comes in September when ABL goes into the air against a missile launch.

Why Lasers

The Pentagon is more optimistic about ABL than some other programs because of its history and what lasers are capable of doing.

ABL dates back to 1997, but much of its early work was completed in laboratories. The program really started moving in the last four years, Rinn said.

The high-power laser utilized by ABL is a chemical oxygen-iodine coil laser developed by Northrop Grumman Corp. Lockheed Martin Corp. designed the front-end of the ABL, which controls the movement of the laser, suppressing jitter in the ABL and directing the energy toward its target after acquisition. Boeing integrated all of the pieces.

“The speed-of-light capability of a laser weapon is a huge advantage,” Rinn described. “If you can see it, you can point at it and kill it in a very rapid time frame. Compared to kinetic weapon systems, the advantage is obvious. If you have a platform that is mobile like a 747—or some other aircraft—it can immediately go anywhere in the world. It is aerial refuelable; it can launch very quickly; and it can project a power as a deterrent or if it actually needed as a weapons system against an aggressor. That timing and that mobility and that flexibility [are] key.”

The U.S. Air Force, therefore, would operate ABL in ways similar to the Airborne Warning and Control System or the Joint Surveillance Target Attack Radar System.

ABL operates on a near-infrared spectrum, making it invisible to the naked eye. The near-infrared energy, however, transmits very well through the atmosphere. The ABL aircraft flies around 40,000 feet, placing it above much of the atmosphere. It then acquires target missiles as they break through the cloud deck—up to hundreds of kilometers away. (Exact ranges are classified.)

“We can acquire them from very long distances,” Rinn asserted. “The profile of that missile is up in the air in the sky so we are pointing up and away. The speed of light gives us a huge advantage and a quick-kill capability, and we can quickly move to another target very rapidly. Compared to kinetic systems, where you have to steam them forward in ships or pre-position them on land, which limits you to that geometry, the ABL can move rapidly, which is a major advantage.”

At that point, also, the missile is still in the boost phase, where the Defense Department would really like to kill it. The reasons for hitting it at that time, too, are simple, Rinn said.

“If you can acquire a missile and kill it in the boost phase, you kill it early,” he stated. “By killing it in the boost phase, there are a couple of huge advantages. It’s vulnerable; it’s very bright; it’s accelerating; it’s under a lot of stresses; it’s over the enemy territory.”

Killing a missile in the boost, ascent or early-intercept phases potentially kills the missile before it can release countermeasures, Rinn added.

Ground-based Lasers

ABL, as its name states, is an airborne laser, but the Pentagon is examining ground-based laser systems as well. Raytheon Co. has a contract to develop the Laser Area Defense System (LADS), which operates from land- and ship-based Phalanx systems. LADS would provide a low-cost directed-energy laser to deliver back up to kinetic energy countermeasures already on the ground.

Raytheon already has developed the Phalanx Close-in Weapon System, which is a radar-guided gun system for shooting down missiles and other air and surface threats close to its perimeter. Phalanx provides full capabilities for detecting targets, evaluating the threats they pose, tracking them and then shooting them down.

DoD in turn already has deployed Phalanx to land and ship positions where it defends U.S. assets from missile attack.

LADS would use Phalanx as a base and add sensors and fire control and beam control to direct a laser against incoming missile targets for a quick and efficient kill of a missile target. Raytheon has demonstrated LADS using a 20-kilowatt IPG Photonics fiber laser from the Air Force.

Research Laboratory (AFRL) and a bench-mounted beam director secured to the top of a Phalanx mount.

The AFRL verified the capabilities of LADS to fire the laser beam and defeat a 60-mm mortar on a test side provided by Sandia National Laboratories. The testing, which occurred in 2007, provided laboratory results that demonstrated the potential of LADS.

“LADS provides a low-cost, near-term directed energy defense that negates rocket, artillery and mortar threats,” Mike Booen, vice president of Advanced Security and Directed Energy Systems at Raytheon Missile Systems, told MSMF.

“It combines the proven capabilities of the operational ship- and land-based Phalanx Close-in Weapon System with the power and speed of a commercial, solid-state laser,” he continued. “Because LADS is powered by electricity, the system offers an affordable and almost infinite magazine to stop mortar and rocket threats. LADS moves Raytheon much closer to delivering speed-of-light protection to warfighters in the battlespace and demonstrates that you don’t need a chemical laser for that mission.”

Solid-state Lasers

Solid-state lasers are not yet ready for prime time, however. Chemical lasers presently have the capability to generate beams of intensity in the megawatts. Solid-state lasers generally only register in the 10s of kilowatts, although Northrop Grumman tested a kilowatt solid-state laser in March.

The solid-state laser is generated by an electric system, which theoretically will provide more laser firings at a cheaper price one day. The Northrop Grumman laser, measured at more than 105 kilowatts, is the most powerful solid-state laser produced to date.

The test occurred as the final demonstration milestone of the Joint High Power Solid State Laser (JHPSSL) program. Demonstrators switched on the laser in less than one second and operated it for five seconds with good beam quality, Northrop Grumman reported. Previously, the company had reached a power level of 30 kilowatts in September 2008.

“Our modular JHPSSL design makes it straightforward to scale laser weapon systems to mission-required power levels for a variety of uses, to include force protection and precision strike missions for air-, sea- and land-based platforms,” Dan Wildt, vice president of Directed Energy Systems for Northrop Grumman Aerospace Systems, said in a statement.

“This achievement is particularly important because the 100 kW threshold has been viewed traditionally as a proof of principle for ‘weapons grade’ power levels for high-energy lasers. In fact, many militarily useful effects can be achieved by laser weapons of 25 kW or 50 kW, provided this energy is transmitted with good beam quality, as our system does. With this milestone, we have far exceeded those needs,” Wildt added.

Northrop Grumman reached the 105-kW measure by combining seven laser chains of 15 kW each to produce a single beam. An eighth laser chain would increase power to 120 kW, according to the company.

At those sizes, JHPSSL will not soon provide a system that the U.S. military can field. But in the future, it may one day provide a solid-state laser that DoD could retrofit onto existing land-, sea- and air-based platforms. ♦

Back to Top