London, September 12 (ANI): Soon, the Airborne Laser (ABL), built into a customized Boeing 747, is ready for flight tests, in which it will try to shoot a ballistic missile.

According to a report in New Scientist, the US Department of Defense’s Missile Defense Agency (MDA) has developed the ABL.

The ABL aims to focus a beam of laser energy in the megawatt range for several seconds onto a missile at a “militarily significant distance” - more than 100 kilometres.

So far, the laser has only operated at near full power on the ground. On August 18, it was fired successfully from the air, but at reduced power.

That, however, was no mean feat, as aircraft vibrations play havoc with the precisely aligned optical components needed to generate a laser beam.

Firing at full power poses other challenges as well.

At powers high enough to destroy missiles, any surface contamination or tiny flaw in the laser optics can absorb so much heat that they crack or shatter.

High-power laser beams also heat the air they pass through, creating perturbations that can disperse or divert the beam.

To counteract those effects, the ABL uses an adaptive system that senses atmospheric changes along its path and makes optical adjustments to compensate.

To test that system, the MDA plans a series of increasingly powerful shots at modified ballistic missiles loaded with sensors to measure the distribution of laser power on the target.

Engineers will assess each shot’s performance and use the results to fine-tune the adaptive optics.

Once this is done, the MDA will test the laser again in varying conditions, and attempt to destroy actual missiles.

The first of these tests is planned to take place late this year, with two more to follow in early 2010, according to an MDA spokeswoman. (ANI)