From missile detection to destruction, the ABL engagement sequence has six basic steps.
| First, the battle manager detects the missile after it breaks through the cloud deck using an infrared search and track system. Six such systems are stationed around the aircraft, providing a 360-degree field of view. The active ranger then determines target range, prioritizes the available targets based on rules of engagement established by the combatant commander, and instructs the beam-control/fire-control system to engage the target at specific inertial coordinates. | |
| Second, the beam-control/fire-control system uses the coordinates provided by battle management to command an inertial sensor in the turret to point to the target, bringing the turret assembly with it. The acquisition sensor located in the turret assembly finds and acquires the infrared signature of the missile plume and adjusts the turret to center the image in the sensor in preparation for handover to the narrow-field-of-view plume tracker. | |
| Third, the plume tracker acquires the hot exhaust of the missile plume through the shared aperture, refines the turret assembly settings, and establishes a missile track file as well as a track point at the leading edge of the plume. The track point and missile kinematics are then used to calculate a pointing angle for the track illuminator laser so that it will hit the missile body. Its beam is then launched and "walked up" (moved forward) from the plume to the missile nose. | |
| Fourth, the return of the track illuminator off the missile is measured in the fine tracker to update the range to target, and the missile image is analyzed to establish and lock onto a nose track point. The pointing angles for the beacon illuminator and the high-energy laser are calculated with respect to the nose track point, and the beacon illuminator is propagated to the target. | |
| Fifth, the return of the beacon illuminator is analyzed by a wavefront sensor to measure atmospheric disturbances. A wavefront sensor is a device that measures the aberrations of an optical wavefront—in this case, the beacon illuminator. The aberrations are an estimate of the atmospheric disturbances and can be corrected using an adaptive optics system similar to those used in astronomical telescopes. The beacon illuminator is pointed ahead of the desired high-energy laser hit spot so that its return samples the same path that the high-energy laser will follow. This allows a deformable mirror to predistort the high-energy laser beam so that it self-corrects as it passes through the atmosphere and arrives focused at the target, providing maximum intensity. This function is referred to as atmospheric compensation. | |
| Sixth, the high-energy laser is fired, and a sample of the outgoing beam is analyzed by a second wavefront sensor. Errors inherent in the beam or generated as it passes through the optical system are corrected by a second deformable mirror. This function is referred to as local wavefront compensation. With local and atmospheric errors compensated for, a spot about the size of a basketball is maintained on the missile, and within seconds, it weakens the missile body. Internal pressure creates a crack that then propagates catastrophically, unzipping the missile skin. | |