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Missile Defense

Russian military leaders have expressed concern about US plans for a national missile defense system. Will defense technology be limited by possibilities for a strategic imbalance? Is this just SDI all over again?

gisterme - 05:02pm Jul 7, 2001 EST (#6740 of 6750)

rshowalter wrote( rshowalter 7/7/01 12:01pm ) The notion that "if we can see it we can hit it" is all through the program, and is ridiculous. In the first days of the artillery course that Napoleon took, people would have been clear that this wasn't true -- then or now -- for fundamental reasons.

What does Napolean's first artillery course have to do with laser aiming, Robert? Have you failed to notice that Napolean didn't have any "speed of light" LOS artillery? Sheesh.

WRT your hypothetical problem, I can't see why that has ANYTHING to do with aiming a laser. Here's one that's more relevant:

Assume a 200m conical rocket plume with a 20m x 3m cylindrical ICBM attached to its leading edge (the point of the cone).

1) Explain why a wide-angle, say 10 milliradian "aiming" laser could not be aimed precisely enough to illuminate the ICBM body using HST-level technology.

2) Explain why the aiming laser would have to be at the same wavelength as the 10^6 x brighter (at infrared wavelenghth) rocket plume.

3) Explain why a sensor attuned to the wavelenghth of the illumination laser (NOT the rocket plume) could not track and aim a laser at the 20m x 3m ICBM body using HST quality optics and pointing technology. Hint: we've already shown that a 10cm diameter beam can be aimed to within +/- 8cm at 10,000km using HST technology.

"...To destroy the target, you have to hit its area -- does anyone really believe that, in this example (which is the simplest and easiest) if you can see it, you can hit it?..."

The problem I've proposed is MUCH simpler and easier than the one you've proposed and is a simple approximation of the REAL problem. You should be able to show why it can't be done, if it can't, using references already posted. I doubt that you'll even try.

continued...

gisterme - 05:05pm Jul 7, 2001 EST (#6741 of 6750)

gisterme 7/7/01 5:02pm continued:

"...Nobody who has ever shot a gun at a target, and experienced how hard the bullseye is to hit, compared to the outer circle, can possible believe that..."

That's a baseless assumption about what folks can believe, Robert. Ever shoot a gun that has no recoil and whose masless bullet travels at 300,000km/Sec? Of course not. Ever aim a gun that has aiming accuracy to within "a few milliarcseconds"? I doubt it. Ever aim one with a 'scope having optics like the HST? Not likely.

"...For one thing, it depends on how well you can see. And it also depends on what you have to shoot with, and how closely you can control the shots..."

Exactly! You've made my point, Robert! Thanks. There's great technology involved; but no miracles requied.

rshowalter - 05:16pm Jul 7, 2001 EST (#6742 of 6750)
Robert Showalter showalte@macc.wisc.edu

Thanks for a definite response. I'll be back to you, but I'll take my time doing it -- it is the weekend.

If you convince me that I'm wrong -- I'll say so. You may recall the elapsed time it took me, yesterday, to respond to Garwin's proposal.

At the same time, I'm moving slowly enough to be comfortable, and I can't remember everything, or do everything at once.

We have that, as one aspect of common ground between us.

You're acting, for the record, as if I've made an impression on you, and perhaps on people you know.

If I'm right, on a core point or two -- that would have an effect on the credibilty of the Rumsfeld-Wolfowitz program -- would it not?

I can afford to take my time.

lunarchick - 05:24pm Jul 7, 2001 EST (#6743 of 6750)
lunarchick@www.com

& GI is staffed!

Clinton (BBC/Wimbledon) still knows how to "WOW" 'em!

gisterme - 05:28pm Jul 7, 2001 EST (#6744 of 6750)

rshowalter wrote ( rshowalter 7/7/01 4:45pm ): "...I saw the 5 seconds a 1 kw/cm^2 all right. My question was -- how damaging is that? -- How much will actually be absorbed as heat, for instance -- and how much damage could that amount of thermal energy do?..."

The reference says that's enough to destroy an ICBM. Did you fail to notice that part? I think it's in the same sentence. Wouldn't you suppose that 1kw/cm^2 for 5 seconds conclusion is based on emperical data? I would.

If an oven broiler delivers 3kW/m^2 then that's 0.3W/cm^2. You know about how long that takes to broil a steak, depending on your taste.

You also know that 1kW/cm^2 (9,000 times as hot as the broiler) applied to a thin metal surface will cut through quite nicely, no matter how far away the energy source is. How much easier would it be to blow out, say, a scuba tank containing 500 psi?

A solid-fuel ICBM booster having 57,000 pounds of thrust and a 12" nozzle would be containing on the order of a 500 psi of internal pressure. Think about it, Robert.

I 'gotta go.

gisterme - 05:37pm Jul 7, 2001 EST (#6745 of 6750)

lunarchick wrote: "& GI is staffed!..."

Huh? Nope. Just one guy, lunarchik...not even claiming to be be a brainiac like Robert does. :-)

gisterme - 05:37pm Jul 7, 2001 EST (#6746 of 6750)

No rush, Robert.

Really gone this time...

(4 following messages)

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