Defense Against (Model) Rockets

In article ,
"Bruce Sterling Woodcock" wrote:

When people talk about "quantum leap" in macro terms, they
are not meaning that it's a big jump per se. It's just that there
are not any INTEVENING steps that would create a more
gradual transition.

Yes, I understand the origin of the term, and this is what people mean
who are using it properly. But I specified people who were using it to
mean a big jump, and I've heard that far more often than the correct
usage. (Or perhaps I just remember it more because it annoys me.)

,------------------------------------------------------------------.
| Joseph J. Strout Check out the Mac Web Directory: |
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Antiaircraft missiles using hobbyist model rocket components would be weak and
wobbly at best. Far easier to fire unguided rockets trailing wire with the plan
of getting the engines to ingest the wire and fail close to the runway on
takeoff, the most vulnerable time. In fact, DARPA studied the idea of nano-
bugs made of titanium that would be seeded by a cluster bomb type delivery
system and simply sit undetected in the grass at the runway's end, waiting to
hear a big jet coming. The bugs then simply swarm, fly up and into the engines
causeing FOD damage. This is a pretty old idea, I think Ayn Rand or a similar
author used variation of it in a book called Ecotopia, probably in the 70's,
where secessionist Californians used unguided rockets trailing strong wire or
kevlar thread were used to defeat helicopters by fouling or shearing their
rotors.

Mike Sabo wrote:

Derek Lyons wrote:
Mike Sabo wrote:

I especially like this comment.

"The lethality of such a system would be exponentially increased if the
miniature rocket payload section would house a proximity explosive
charge, instead of a grazing or impact warhead."

Exponential increase? Yeah, right. At least I know not to send my kids
to Case Western if they want to get an engineering degree.

Or to put it simply; Look up what kinds of fuses 'real' _AM's use and
why.

Yes, they use proximity Fuzes. In this case, are you not trading off an
already miniscule warhead size for something even smaller but with a
proximity fuze?

A proximity fuse need not be that big. (And a reliable
contact/grazing fuze isn't small either.)

The author's premise is that you already have a guidence
system that will lead the rocket to the bottom of the cargo bay,

Not in the referenced article.

"expontially" increasing the probability of a direct hit in that area.
Won't the Wonder Weapon with a size X warhead against the skin of the
cargo bay have a greater potential for causing damage than one with a
size X-Y at 2 meters +/- Z below the cargo bay?

Consider the extreme difficulty of design a Wonder Weapon where you
have even a reasonable chance of actually making contact with the
skin, anywhere on the skin. (Note that none of the 'advanced' nations
have done so.) It can be seen by extrapolation that using a contact
fuse yields only a binary possibility, "Hit" or "Miss".

Whereas a proximity fuse gives a continous variable from "Clean Hit"
through "Limited Damage" to "Clean Miss".

D.
--
The STS-107 Columbia Loss FAQ can be found
at the following URLs:

Text-Only Version:
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Enhanced HTML Version:
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Corrections, comments, and additions should be
e-mailed to , as well as posted to
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discussion.

Mike Sabo wrote:
Yes, they use proximity Fuzes. In this case, are you not trading off an
already miniscule warhead size for something even smaller but with a
proximity fuze? The author's premise is that you already have a guidence
system that will lead the rocket to the bottom of the cargo bay,
"expontially" increasing the probability of a direct hit in that area.
Won't the Wonder Weapon with a size X warhead against the skin of the
cargo bay have a greater potential for causing damage than one with a
size X-Y at 2 meters +/- Z below the cargo bay?

Reread the article closely and found the spot about the homing system
leading a bird directly to the target, my apologies.

A proximity fuse, in this instance, increases lethality in two ways;

1- it increases the launch envelope, and;

2- decreases the chance that a high bearing rate during the terminal
intercept phase will cause either a clean miss or cause the missile to
tumble because of the high turning rate needed.

D.
--
The STS-107 Columbia Loss FAQ can be found
at the following URLs:

Text-Only Version:
http://www.io.com/~o_m/columbia_loss_faq.html

Enhanced HTML Version:
http://www.io.com/~o_m/columbia_loss_faq_x.html

Corrections, comments, and additions should be
e-mailed to , as well as posted to
sci.space.history and sci.space.shuttle for
discussion.

Henry Spencer wrote:
In article ,
Mike Sabo wrote:

Won't the Wonder Weapon with a size X warhead against the skin of the
cargo bay have a greater potential for causing damage than one with a
size X-Y at 2 meters +/- Z below the cargo bay?


If the former can be achieved, yes. But in practice, that is formidably
difficult, and the alternative to a proximity fuze is usually no explosion
at all because you missed.

Got that. The numbers game.

Derek Lyons wrote:

Mike Sabo wrote:


Derek Lyons wrote:

Mike Sabo wrote:


I especially like this comment.

"The lethality of such a system would be exponentially increased if the
miniature rocket payload section would house a proximity explosive
charge, instead of a grazing or impact warhead."

Exponential increase? Yeah, right. At least I know not to send my kids
to Case Western if they want to get an engineering degree.

Or to put it simply; Look up what kinds of fuses 'real' _AM's use and
why.

Yes, they use proximity Fuzes. In this case, are you not trading off an
already miniscule warhead size for something even smaller but with a
proximity fuze?


A proximity fuse need not be that big. (And a reliable
contact/grazing fuze isn't small either.)

In a _AM, don't they normally use a pre-fragment or continuous rod
around the warhead to maximize the damage? It doesn't seem like a paper
tube or fiberglass shell would do much to cause additional damage, so
you would have to detonate awfully close to the skin anyway to a chance
for the shock to damage a system or to spall off a piece of metal and
cause a secondary. If you augment the warhead to maximize damage, then
you reduce your explosives even further. For comparison, an SA-7 has 2.5
lb of HE and an FIM-92 has 6.5 lb of HE. With payloads in this range,
could you really get to 1000' with a size G or H motor? Extrapolating
from some numbers used with smaller motors, I would guess no.

(MSu1049321) wrote in message ...
Antiaircraft missiles using hobbyist model rocket components would be weak and
wobbly at best. Far easier to fire unguided rockets trailing wire with the plan
of getting the engines to ingest the wire and fail close to the runway on
takeoff, the most vulnerable time. In fact, DARPA studied the idea of nano-
bugs made of titanium that would be seeded by a cluster bomb type delivery
system and simply sit undetected in the grass at the runway's end, waiting to
hear a big jet coming. The bugs then simply swarm, fly up and into the engines
causeing FOD damage. This is a pretty old idea, I think Ayn Rand or a similar
author used variation of it in a book called Ecotopia, probably in the 70's,
where secessionist Californians used unguided rockets trailing strong wire or
kevlar thread were used to defeat helicopters by fouling or shearing their
rotors.

True. And far easier too to simply drive an explosives-laden
truck (one of those fuel or food supply trucks probably) up to
a fully-fueled, fully-passengered jet just before it pushes
back from the gate or just beneath it as it crosses over one
of those taxiway bridges over an access road, etc...

Or forget the planes. Go after a commuter train, one of the
thousands of such totally unguarded trains that run in this
country each day, some carrying literally thousands of people
at a time (use grenades and pistols or use fire the way they
do in India, or just stop a big petrol truck in front of it).
Or block traffic in a highway tunnel with an LPG tanker truck,
open the valves, light a match. Or set a fire in one of
those grandfathered unsprinkled skyscrapers, or in a crowded
nightclub or church, or drive around the suburbs with a sniper
rifle in a car that has a little hole cut in the trunk.

Killer guided model rockets, sheesh.

- Ed Kyle

"Joe Strout" wrote in message
...
In article ,
"Bruce Sterling Woodcock" wrote:

When people talk about "quantum leap" in macro terms, they
are not meaning that it's a big jump per se. It's just that there
are not any INTEVENING steps that would create a more
gradual transition.

Yes, I understand the origin of the term, and this is what people mean
who are using it properly. But I specified people who were using it to
mean a big jump, and I've heard that far more often than the correct
usage. (Or perhaps I just remember it more because it annoys me.)

The point is I don't believe you heard them use it to mean a
big jump. They use it to mean a jump that is larger than a
more anticipated gradual transition. At the macro level, it
may look like a "big jump" but it's all relative.

Bruce

On Fri, 24 Oct 2003 09:33:05 -0500, Mike Sabo
wrote:

In a _AM, don't they normally use a pre-fragment or continuous rod
around the warhead to maximize the damage?

They use rod in AIMs, which are a lot smaller than non-MANPADS SAMs.
The Soviet SAMs used in Vietnam didn't use rod; they produced shrapnel
but I don't know if they were pre-frags or not.

Mary

--
Mary Shafer Retired aerospace research engineer

On 24 Oct 2003 07:47:26 -0700, (ed kyle) wrote:

Or forget the planes. Go after a commuter train, one of the
thousands of such totally unguarded trains that run in this
country each day, some carrying literally thousands of people
at a time (use grenades and pistols or use fire the way they
do in India, or just stop a big petrol truck in front of it).

Taking of Pelham 123, for fiction. South Moluccans in Holland, for
reality.

Or block traffic in a highway tunnel with an LPG tanker truck,
open the valves, light a match.

I don't remember the name of this book, but the tunnel was in
Virginia. Maybe the one to the Delmarva peninsula or the one between
Norfolk and Hampton Roads.

Or set a fire in one of
those grandfathered unsprinkled skyscrapers, or in a crowded
nightclub or church, or drive around the suburbs with a sniper
rifle in a car that has a little hole cut in the trunk.

Al Qaeda just did one of these in Bali, except it was a bomb, not a
fire. A rock band set the fire in the nightclub, using fireworks.

Mary

--
Mary Shafer Retired aerospace research engineer