CNN reports that the first commercial jet with an onboard anti-missile laser system is now in operation. It's part of a pilot program to see how Northrop Grumman's Guardian anti-missile system behaves on a working commercial jetliner, and what impact it has on its maintenance and operational schedule.

The system works by firing an invisible laser beam at the guidance system of an on-rushing missile, disrupting it and causing the projectile to miss the plane. The goal is to prevent attacks by shoulder-launched missiles, but since officials say it could take 20 years to equip the commercial fleet with such system, you have to wonder if it's worth it. Won't some other, more modern threat to planes have emerged by then? Or will the missile technology be so cheap and widespread that we'll have terrorists regularly taking potshots at jetliners as they fly overhead?

The more immediate goal of equipping all jetliners contracted by the military to carry troops seems more doable and realistic, since I'm guessing these are the ones most likely to see missile fire.