Long ago, in a galaxy far, far away!

[revwardoc]

STAR WARS IS ALIVE AND WELL...AND WEARING AIR FORCE BLUE!

ABL Prepares for 2005 Shoot-Down Attempt

By Robert Wall

August 31, 2003

Countdown to Shootdown After years of development, the Pentagon is about to learn whether its investment of time and millions of dollars in the Airborne Laser missile defense system has paid off. Since 1996, the Missile Defense Agency (MDA) and Air Force have concentrated on developing and testing various system components--the megawatt-class laser, optics, battle management suite, the modified Boeing 747-400F--but during the course of the next year all those elements will have to be integrated to confront one major remaining challenge: shooting down a boosting ballistic missile over the Pacific. What lies ahead in the coming months is expected to be a difficult engineering endeavor. Program managers recognize that they still have to overcome high hurdles, and indicate the shootdown attempt is likely going to occur in 2005, not late 2004. "It gets more and more challenging to hold to the 2004 date," notes ABL program director USAF Col. Ellen M. Pawlikowski. The shootdown attempt should go a long way toward addressing the main questions hanging over ABL: can adequate laser energy be generated to overcome atmospheric absorption, can the energy be focused on a small enough point to damage a missile, and will the software-intensive battle management system work? Even a successful test won't convince all critics, since the first test will be at relatively close range, intentionally designed to demonstrate system functionality rather than determine if the ABL can accomplish its mission in a stressful setting. Once the test is complete, Pentagon officials are mulling the possibility of using ABL in case of a crisis, not unlike the first deployments of the Predator and Global Hawk unmanned aircraft. The aircraft may not be used to shoot down ballistic missiles, but could serve in the role of a massive sensor and as a battle management node. But there are no concrete plans to move the YAL-1A, or even the next version, the Block 2008 aircraft, into Air Force inventory, says Lt. Col. Richard Nefzger, ABL chief of the Air Force's operational branch, Air Combat Command. Concepts for an early operational use of ABL are relatively far advanced, given the status of the project. The integrated test force has been heavily involved in drafting an emergency plan. If the order to deploy came, test personnel would likely be the ones to operate the system, says USAF Lt. Col. Keesey R. Miller, director of ABL's integrated test force. The test team already includes personnel from Air Combat Command, which could help smooth use during an emergency. The long-term operational concept is for ABL to be based in the U.S. but to be deployable within 24 hr. The aircraft would establish its patrolling orbit in the same areas "as close to the battlefield as possible" without endangering crew, Nefzger said. Like Joint-STARS and AWACS surveillance assets, ABL would be protected by other aircraft. Program officials are pressing hard to reach the shootdown milestone. Teams assembling the system integration laboratory (SIL) where the laser will be tested before installation on the 747 are working three shifts, six days a week, Miller highlights. But for most of the major components there is no redundancy, so component failure could set back the schedule significantly. The recognition that more delays may lie ahead stems from experience gained during the last several years. Although the major sub-elements of ABL now appear ready, reaching this point has not been easy. The program had to contend with supplier and technical problems that slowed development. ABL managers argue that the lows were overcome and note that they have achievements to show for their efforts. Among them is a series of tests during which TRW, now part of Northrop Grumman, validated the performance of the first of the high-power chemical oxygen iodine laser (COIL) modules ABL will use. The laser work culminates about 20 years of research, Pawlikowski noted. Other highlights include manufacturing materials that can withstand the harsh environment presented by the chemicals that power the laser and aircraft operations. "Many of the pieces are first-of-a-kind," Pawlikowski added. While the high-power laser to destroy the missile receives most of the attention, the tracking illuminator laser (TILL) and beacon illuminator laser (BILL) used to target the missile represent their own accomplishments, both being relatively high-power solid state devices. All three of ABL's main lasers--COIL, TILL and BILL--operate at different wavelengths. The program also has undergone an initial flight test series of the modified Boeing 747 and tracked a ballistic missile launch from Vandenberg AFB, Calif., as part of a ground-based mid-course intercept test (IFT-10). The intercept attempt was a failure for the ground-based system but a success for ABL because it was able to track the target. In the build-up to the shootdown, ABL will undergo a series of key events that will determine when the graduation exercise can be scheduled. The most significant of those is slated to take place this fall when all six laser modules are integrated and the first attempt is made to produce power. Lockheed Martin has also been assembling the main optical system. Once it is fully checked out it will be shipped to Edwards and integrated on the 747 along with the laser. The goal is to determine what the limitations of each component are, Pawlikowski said. Only once the major elements are combined will ABL resume flight testing. "The bar is set pretty high, technically," Miller added. During a typical engagement, ABL would loiter at 40,000 ft. and at relatively low speed. The crew would be alerted to a ballistic missile launch by outside sensors that relay the information via Link-16 or another data link. The aircraft's infrared search and track sensors would then pick up the missile and cue, using the battle management function, the active ranging sensor. Based on that information, the turret would be steered to pick up the target using a high-resolution infrared camera. Once the turret has captured the target, the TILL is used to identify the precise location of the ballistic missile, after which the BILL is to provide a target for the high-power COIL. ABL's top-mounted active ranging sensor will not be participating in the initial test. Following flight tests last year, engineers realized it needed to be redesigned because it imparted too much lateral motion on the aircraft. The device isn't needed during the test because the scenario is staged and only one target is employed. The main role for the active sensor is to help track and prioritize multiple targets. In future, one of the main problems ABL managers will have to wrestle with is weight, in particular its distribution. There are places where inordinate stress could be put on the aircraft if the weight of components increases. Some of the tanks containing COIL's chemical ammunition already are heavier than expected. Pawlikowski acknowledges that "we have had more weight growth than we had anticipated at [critical design review]." This occurred in part because laser components that were to have been made of composites had to be made of titanium instead. But both Miller and Pawlikoski argue that weight shouldn't be a problem, at least for the YAL-1A. The aircraft is certified for operations with a gross take-off weight above 800,000 lb., while the mission weight for the prototype is expected to be 660,000 lb. Weight could be a concern in the long run, however, as ABL won't necessarily be able to cruise climb, like a freighter, but may need to reach its 40,000-ft. operating altitude immediately. If the system is too heavy it won't be able to do so. "Weight is still very much a watch item for me," Pawlikowski said.