Sci-Fi Weapons to Join US Arsenal?

marct22 writes to tell us CNet is reporting that the next weapons coming out of the US arsenal could be stepping right off the pages of science fiction to be there. From the article: "By the end of this year, the Air Force plans to conduct a first, fully loaded test flight of its Airborne Laser, a jumbo jet packed with gear designed to shoot down enemy missiles half a world away, at the speed of light. The ABL also packs a megawatt-class punch--it's not exactly your garden-variety laser pointer."

Comments

Re:Half a world away?

[Anonymous Coward]

Wouldn't be too hard

God, how I hate that statement! Yes, it would be hard. In addition to atmospheric attenuation and disturbance in the beam, you have beam divergence spreading the beam out, and diffraction off of the mirror edges throwing it everywhere. By the time you get to the other side of the world, maybe you can use it as a night light.

Re:Half a world away?

[Bad D.N.A.]

Wouldn't be too hard to coordinate with a satellite to bounce off of them. I'd just be concerned about the laser transmission loss going through the atmosphere for that long of a distance.

To coordinate with a satellite... easy. To worry about the transmission loss... irrelevant. To achieve the pointing requirements, both from the plane and the spacecraft, to hit the target (priceless... literally...). What happens when a little gust of wind hits the plane (they do bounce around a bit). Your beam will miss the target by many kilometers (and that's if you were lucky enough to hit your mirror-in-space?). GPS or something along those capabilities would not even come close to the resolution required for this type of thing, to say nothing of a moving target, a moving source, and a moving relay.

Re:Overcoming countermeasures?

[BJZQ8]

All of this research was done a long time ago. The laser delivers its power in such a burst that no amount of mirroring or spinning will make a difference. As to the atmospheric attenuation, that's what the laser's adaptive optics are for. It's kind of like a telescope in reverse. In any case, this sort of thing was tried for short-range defense in the 70's, and even a small laser was capable of shooting down Sidewinders (mounted on a KC-135.) We're talking about serious firepower here...this thing was tested at a low-altitude range of 50km, and worked fine...up in the high atmosphere where they hope to catch boost-phase weapons, it should be much easier. It's not like the things can evade or maneuver, after all, they're called ballistic missiles for a reason.

http://www.nae.edu/nae/bridgecom.nsf/weblinks/MKEZ -4ZPQHJ?OpenDocument