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To: dragnet2
While ballistic missiles like the one ALTB destroyed move at speeds of about 4,000 miles per hour, they are no match for a super-heated, high-energy laser beam racing towards it at 670 million mph.

The speed of the beam is irrelevant. The difficult task is keeping it focused on the moving target long enough to do the job AND having enough power in the beam to get the job done. A pulsed beam is best as a steady beam can lose effectiveness as super-heated metal vapor blocks/reflects some of the beam. The first successful use of a weapons grade laser was accomplished by one of my co-workers in San Diego.

19 posted on 02/12/2010 8:52:02 PM PST by Myrddin
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To: Myrddin
The difficult task is keeping it focused on the moving target long enough...

You're right. Did you notice the beam hit the target and stayed on it? There was no evidence of any overshoot - nothing went past the missile.

This is a "good trick" for whatever they are using as a tracker. A boosting missile is not only moving relative to the ABL, it is accelerating. Not only accelerating, but the rate of acceleration is changing. Rocket thrust can be taken as mostly constant, yet the vehicle is burning off fuel, getting lighter, so acceleration is increasing. Yet as speed increases, so does drag, but as altitude increases, air density decreases and so does drag...

There are a lot of factors and it becomes a complex problem for a tracking algorithm. Yet that beam stayed locked on tight. I don't know the diameter of the ABL beam, nor the diameter of the test missile but... That ball on the ABL for optics is pretty big. Even the biggest ballistic missiles are only a couple of meters in diameter, a short range test target is probably only a meter or so in diameter... Yet that beam never wavered off and overshot past the target...

Also consider, they have to have optics that can look right past their own beam and focus on the target to track it and keep the beam pointed at the target... Kind of like trying to follow the lines on the road in a blizzard with your high beams on...

29 posted on 02/12/2010 9:41:41 PM PST by ThunderSleeps (obama out now! I'll keep my money, my guns, and my freedom - you can keep the change.)
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To: Myrddin
"While ballistic missiles like the one ALTB destroyed move at speeds of about 4,000 miles per hour, they are no match for a super-heated, high-energy laser beam racing towards it at 670 million mph."

The speed of the beam is irrelevant.

Not my quote...But I would guess the speed of the deterrent missile/beam or whatever, would be very relevant to the speed of the target object. In this instance though, I think the author was just attempting those show the readers what the laser speed was compared to a conventional rocket/missile.

The difficult task is keeping it focused on the moving target long enough to do the job AND having enough power in the beam to get the job done.

I imagine that would depend on the target object, distance, angle of travel, and the delivery platform, all done with computers, with the computers compensating/adjusting for all that movement in a super fast manner.

The first successful use of a weapons grade laser was accomplished by one of my co-workers in San Diego.

Actually I think the first successful field test for a weapon laser was conducted in White Sands N.M.

32 posted on 02/12/2010 10:47:26 PM PST by dragnet2
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