Comments on: Death Ray — or Accounting Shift?

By: ara

ara — Sun, 13 Jul 2008 20:48:23 +0000

My WeB Site
way ananas?k?m
kurtlar vadisi
kiral?k araba
minib

By: ara

ara — Sun, 13 Jul 2008 20:48:23 +0000

My WeB Site
way ananas?k?m
kurtlar vadisi
kiral?k araba
minib

By: JSAllison

JSAllison — Thu, 04 May 2006 14:05:44 +0000

UBL is becoming a sideshow attraction, which is a good thing. I don’t see how DoD keeping their eye on larger issues is bad, in fact if they weren’t I’d be expecting DefTech and others to be calling them out on it.

By: Carrick

Carrick — Thu, 04 May 2006 12:40:18 +0000

From the military perspective, this is the development of a weapon that would allow the disabling of surveillance & military communication satellites in the event of a war against a space-capable enemy. This makes perfect sense as more and more nations are become space-capable over time, and we don’t get to choose who our enemies are.
The technology (adaptive optics) also has plenty of peaceful uses in the meantime.
I suppose critics of this program would prefer we bury our heads in the sand or remain myopically focussed on the pursuit of OBL (like getting him would change anything in any event), then in the event of such a war, blame the administration for its failure to pursue such a policy?

By: red river

red river — Thu, 04 May 2006 07:26:58 +0000

Re-entry vehicles are tough in what sense?
It really depends on the radiation used in the laser and the pulse structure. Every material has certain light frequencies which it will absorb readily and the surface physics — both ablative plasma and surface evaporation due to laser effects — can be overcome by pulsating the laser to deliver several very intense jolts over seconds.
The big payoff in lasers in ICBM interdiction is in the boost and coast-phase of the launch. A laser that can operate in the atmosphere can attack ICBMs from a great distance.
As for “barriers” — the Russians and Chinese have tested Earth-based beam systems since the 70s as well as space-based suicide satellites.
What this boils down to is another ignorant reporter.

By: Slartibartfast

Slartibartfast — Thu, 04 May 2006 05:02:31 +0000

“I thought the Air Force had a missle weapon, carried by the F-15, that could shoot down satellites… Was that only for low-orbit birds?“
You’re talking about ASAT, made by LTV Aerospace (now part of the LockMart Borg consortium) which was scrapped back in the mid to late ‘80s. There was an ASAT program bid out a few years later; I worked over the Christmas holiday only to have my company no-bid it.
Apparently Boeing has won the KEASAT program, but I have no idea if it’s still around. Amusingly, the purported photo of the prototype vehicle fas.org has up on its KEASAT page is actually a picture of a Martin Marietta prototype.
I have no idea what capabilities we have in place now. Hitting a satellite up at half geosynch would take a serious stack, I think. Going up to LEO altitude (100‑1000 miles, roughly) is probably not hard.

By: Terry

Terry — Thu, 04 May 2006 05:00:38 +0000

DS wrote: “I don’t see how this would work. You fire the laser up through the atmosphere, detecting distortion. With a lens, you can deform the lense to correct for the distortion, and get a clear picture, but how do you deform a laser beam to correct for the distortion??? “
Not so difficult. Point a laser at the deformable mirror setup that corrects the atmospheric distortions. Tweak your system so that the correction is best at the wavelength of your laser. Wait for the PSF to reach a minimum and turn the laser on for a fraction of a second. Zap! R-nought (you can think of it as the time that correction is good for) is measured in tens or hudreds of milliseconds in the red end of the visual spectrum. If your system is fast enough you have enough time to zap the satelite while you’ve got effective correction. The idea would be, I think, to disable the satelite rather than destroy it. IR detectors on satelites are very sensitive. Wouldn’t take too much power to blind one.
The real trick would be designing a telescope/AO system that could track a satelite at several degrees per second. R-nought would tend to decrease and so the “window” of time where you could accurately deliver a focused laser would decrease to possibly microseconds. This means you would need a much more powerfull laser …

By: Slartibartfast

Slartibartfast — Thu, 04 May 2006 04:50:58 +0000

Drat. You don’t take links.
Well, look here: http://www.wsmr.army.mil/pao/FactSheets/laser.htm

By: Slartibartfast

Slartibartfast — Thu, 04 May 2006 04:49:41 +0000

We’ve had ground-based laser weapons for quite some time, now. Not deployed, but certainly experimental.

By: Sean

Sean — Thu, 04 May 2006 04:39:43 +0000

Broad is being particularly unfair to both the Air Force and critics of this particular experiment, like me, by giving the last word to an activist group warning that, if the experiment is conducted, “the barrier to weapons in space will have been destroyed.” He’s being unfair, not to you, but to the truth:
1) There is no “barrier” to weapons in space
2) This “weapon” wouldn’t be located there
3) This isn’t a “weapon” as much as a mechanism
for disabling space-based sensors (or space–
based “weapons”)