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  #21  
Old July 10th 03, 01:23 PM
Sander Vesik
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Default Armadillo Aerospace drop test

George William Herbert wrote:
Kaido Kert wrote:
I agree with everything you say, but i have this one important nitpick:
rocket technology equals missile technology NOT.
While its true that most modern missiles of all kinds are propelled by
various rocket engines, a rocket is not a missile.


There are other things that missiles need, other than what a
space launch type rocket can bring to the table.
And military applications tend to optimize on solution
spaces differently than space launch (storability,
etc being larger concerns).

However, the dual use nature and convertability

^^^^^^^^
ah, see there is a big problem here. As things stand
you end up with a big mondo list, that just about
includes "soap" (armies have to wash themselves every
now and then) and shoclate (aka high energy food you
might pack for your troopps). Not only is teh notion and
lits of dual-use goods ill-thought out concept, it is
also in its present incarnation wrong, irrelevant and
there is no meaningful oversight what appers in it.

of many space launch systems to weapons purposes
is hard to avoid.

A lot of CATS amateurs haven't looked at the military
side enough to understand that the differences between
modern rockets and missiles don't mean there isn't
a significant dual use problem. There is. Really.
Even John Carmack's and Burt Rutan's equipment could
be made into medium grade SRBMs, the Armadillo stuff
without too much effort.


you should take a look at the 'how to build a cruise
missle with $5000' page from New Zealand... IIRC no dual
use goods at all were involved.


Over the long term (20 years) proliferation of low
cost rocket technology is a lost cause IMHO.


It is lost *now*. For that matter, I cant'tthink of
any reasson why one would claim this was not always
the case in the first place.

Over the medium term (5-10 years) how we treat
the technology in terms of level of detail we
publish and allow foreigners open access to could
make a large difference in hostile nations
capability growth.


This is fundametaly wrong - it has been demonstrated
times and times again by states other than the US that
the US has no monopoly on bright minds who grok rockets.
All the present mindless thrashing what can and cannot
be published will result is in a stunted growth rate
for sciences inside the US.


This is not an ideal situation, but it is reality.


But a changable part of it.


-george william herbert



--
Sander

+++ Out of cheese error +++
  #22  
Old July 10th 03, 03:15 PM
Andrew Case
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Default Armadillo Aerospace drop test

Sander Vesik wrote:
George William Herbert wrote:

However, the dual use nature and convertability

^^^^^^^^
ah, see there is a big problem here. As things stand
you end up with a big mondo list, that just about
includes "soap" (armies have to wash themselves every
now and then) and shoclate (aka high energy food you
might pack for your troopps).


Since the other side (whoever they are) already knows how to make soap and
chocolate, there's no problem.

Not only is teh notion and
lits of dual-use goods ill-thought out concept, it is
also in its present incarnation wrong, irrelevant and
there is no meaningful oversight what appers in it.


Dual use is a useful concept when talking about technologies that the
other side (potential enemies) does not have easy access to. Rocket
engines and guidance systems are exactly such technologies when the
potential enemies in question are Iran, North Korea, or nations at a
similar stage of technological development. There is no way a reasonable
person can conclude that such nations would not be helped in their weapons
development program by technologies currently being developed for X-Prize
class vehicles. There may be differences in certain details between
weapons-optimized engines and guidance and transport-optimized engines and
guidance, but there is unquestionably a significant overlap.

There is a separate issue of whether export restrictions are effective,
and whether alternative strategies (such as a vigorous missile defense
program) might provide better security.

you should take a look at the 'how to build a cruise
missle with $5000' page from New Zealand... IIRC no dual
use goods at all were involved.


The cruise missile in question has never flown. Even if it had flown, it
has no bearing on other technologies that might be used to make
weapons. This keeps coming up when possible use of rocket related
technologis to build weapons is discussed - people start designing
alternative weapons systems and tactics for terrorists to use, and
claiming that they are simpler than slapping a stick of dynamite on a
model rocket. Even if true, it doesn't impact the utility of
rockets. Similarly, even if the garage cruise missile works, it says
exactly nothing about the utility of transportation rocket engines and
guidance systems for military purposes.

Over the long term (20 years) proliferation of low
cost rocket technology is a lost cause IMHO.


It is lost *now*. For that matter, I cant'tthink of
any reasson why one would claim this was not always
the case in the first place.


Because North Korea has been having a hard time getting their long range
missiles to work. The fact that they've had some recent successes is no
argument for making their task any easier.

Over the medium term (5-10 years) how we treat
the technology in terms of level of detail we
publish and allow foreigners open access to could
make a large difference in hostile nations
capability growth.


This is fundametaly wrong - it has been demonstrated
times and times again by states other than the US that
the US has no monopoly on bright minds who grok rockets.


And it has been demonstrated time and again that people outside the US
have had their tasks made easier by access to technologies from within the
US (and vice versa). The stupidity of US export regulations in their
current form should be understood for what it is - an overreaction to a
real problem, not simple random idiocy.

.......Andrew

--
--
Andrew Case |
|
  #23  
Old July 11th 03, 01:09 AM
George William Herbert
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Posts: n/a
Default Armadillo Aerospace drop test

Sander Vesik wrote:
George William Herbert wrote:
Kaido Kert wrote:
I agree with everything you say, but i have this one important nitpick:
rocket technology equals missile technology NOT.
While its true that most modern missiles of all kinds are propelled by
various rocket engines, a rocket is not a missile.


There are other things that missiles need, other than what a
space launch type rocket can bring to the table.
And military applications tend to optimize on solution
spaces differently than space launch (storability,
etc being larger concerns).

However, the dual use nature and convertability

^^^^^^^^
ah, see there is a big problem here. As things stand
you end up with a big mondo list, that just about
includes "soap" (armies have to wash themselves every
now and then) and shoclate (aka high energy food you
might pack for your troopps). Not only is teh notion and
lits of dual-use goods ill-thought out concept, it is
also in its present incarnation wrong, irrelevant and
there is no meaningful oversight what appers in it.


I'm sorry, but that is just idiotic. We are not
discussing food or bathing products. We are discussing
vehicles that travel at supersonic, hypersonic, or
orbital velocities with small to large payloads,
with precision guidance systems.

You could turn the Armadillo vehicle into a SRBM with
a 3-person-weight HE bomb and a software update.
That is one of the very good reasons that governments
want to monitor and provide oversight on launch
type activities.

Declaring that space launchers, even reusable ones,
are not capable of being used for military purposes
or being developed into militarily useful weapons
systems is wrong. This point is not debatable.
Some of them make remarkably bad weapons.
The current lines drawn regarding the risks
of various technologies are arguably wrong.
But space launch *is* a major missile technology
proliferation risk area. Period.



you should take a look at the 'how to build a cruise
missle with $5000' page from New Zealand... IIRC no dual
use goods at all were involved.


The question is not 'can one proliferate missiles
without using dual use or space launch tech'.

The question is, 'does space launch tech constitute
a missile technology proliferation risk' and the
answer is Yes.

Over the long term (20 years) proliferation of low
cost rocket technology is a lost cause IMHO.


It is lost *now*. For that matter, I cant'tthink of
any reasson why one would claim this was not always
the case in the first place.


How many foreign missile programs have you studied?

I have studied enough to have contributed some of the
early analysies of looking at Japan's space launchers
as a candidate ballistic missile project, and looked
at other nations varied ballistic missile projects
in a fair depth. What we're doing here now in the
US is a lot different and potentially a lot cheaper.

It is going to get out eventually, and possibly sooner
rather than later, but it getting out to some people
is clearly a bad thing.

Sticking your head in the sand about the problem and
risks is not a technically, politically, or morally
reasonable attitude. There is no clear right answer,
and I am certainly not happy with where the laws are
now and some of the restrictions. But the core issues
are real and serious.


-george william herbert


  #24  
Old July 12th 03, 05:50 PM
Rand Simberg
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Posts: n/a
Default Armadillo Aerospace drop test

On Wed, 9 Jul 2003 10:32:59 +0200, in a place far, far away, "Ultimate
Buu" made the phosphor on my monitor glow in
such a way as to indicate that:


Welcome to the world of high density fuels and non-NASA designs. Why does

it
look a little small to you? If you read the web page you will note that

this
drop was done with the smaller of two tanks, and if it turns out they need
more fuel, they will just swap tanks. Now that is what simple designs let
you do. If you read the rest of the website you will see that flight hops
and test firng of the engines already means they know thier fuel

requirements.


I always assumed that hydrogen peroxide packed a much smaller punch per
pound and that therefore a lot more fuel would be needed. If it works with
this or a slightly larger tank, so much the better! But if it works, I'm
starting to wonder why al other rockets have to be so large and cumbersome
compared to John's elegantly small design.


John's design is small because it isn't going to orbit. Most "other
rockets" do...

--
simberg.interglobal.org * 310 372-7963 (CA) 307 739-1296 (Jackson Hole)
interglobal space lines * 307 733-1715 (Fax) http://www.interglobal.org

"Extraordinary launch vehicles require extraordinary markets..."
Swap the first . and @ and throw out the ".trash" to email me.
Here's my email address for autospammers:
  #25  
Old July 12th 03, 09:51 PM
sanman
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Posts: n/a
Default Armadillo Aerospace drop test

Hi Mr Carmack,

Your site weblog said the following:

"When we got it back to the shop, we pulled some things apart to take
a closer look. The bent mounting studs unscrewed right out of their
mounts, so replacing those is trivial. We are considering adding some
more bracing below the engine plates, which would probably keep them
from bending at all. When we got the crush cone off, we did find that
the cabin had been bent right at the end of the cone, and the buckle
in the crush cone had pushed in far enough to crease the honeycomb
bulkhead."



Well, my understanding is that there are now various grades of
carbon-fiber loaded engineering polymer resins on the market, which
show more flexion under stress and have pretty high strength. They
would likely provide weight savings relative to whatever alloy you're
using, and can more readily be formed into parts. Have you ever
considered using something like that for part of your spacecraft?
Perhaps an inner hull, just to ensure pressure integrity in the face
of repeated usage? Maybe the key to a simpler but successful design is
in more expensive, better-performing materials.
  #26  
Old July 13th 03, 03:44 PM
John Carmack
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Posts: n/a
Default Armadillo Aerospace drop test

(sanman) wrote in message . com...
Hi Mr Carmack,

Your site weblog said the following:

"When we got it back to the shop, we pulled some things apart to take
a closer look. The bent mounting studs unscrewed right out of their
mounts, so replacing those is trivial. We are considering adding some
more bracing below the engine plates, which would probably keep them
from bending at all. When we got the crush cone off, we did find that
the cabin had been bent right at the end of the cone, and the buckle
in the crush cone had pushed in far enough to crease the honeycomb
bulkhead."



Well, my understanding is that there are now various grades of
carbon-fiber loaded engineering polymer resins on the market, which
show more flexion under stress and have pretty high strength. They
would likely provide weight savings relative to whatever alloy you're
using, and can more readily be formed into parts. Have you ever
considered using something like that for part of your spacecraft?
Perhaps an inner hull, just to ensure pressure integrity in the face
of repeated usage? Maybe the key to a simpler but successful design is
in more expensive, better-performing materials.


All we need is a little more bracing in a couple places, no big deal.

There are Really Large benefits to working with relatively low
strength aluminum for development projects. You can weld handles on,
grind them off, drill holes all over the place, then fill them back
in, and it doesn't really effect the strength of the design. If you
started with a highly optimized alloy or composite system you could
save weight, but every modification would impact the design. High
tech composites often don't like random holes being punched in them,
and strong metals usually can't be welded without ruining the heat
treatment.

It was also rather surprising how much cheaper rolled aluminum
construction was. For complex curves like airfoils, composites are
often cheaper to fabricate, but if your design can be built with just
sheet metal brake and roll work, it is much cheaper, because the final
product is completely self supporting during fabrication. There is a
good lesson here -- opting for an ogive nose cone instead of a conical
one could quadruple the cost, or more, for very minor theoretical
gains. Fabrication difficulties are easy to overlook when making
clean sheet designs.

The basic idea of using exotic materials to simplify the rest of the
design has a lot of merit, but we haven't hit on a poster-child case
for it yet. I spent a good chunk of money researching radiatively
cooled engines of exotic construction: TZM (moly alloy) base with a
disilicide oxidation protection coating, sealed to the injector with a
silver plated, nitrogen pressurized metalic O-ring. It was very
simple, and it worked, but it cost a LOT, and there were unanswered
fabrication questions in scaling it up from the 50lbf size we tested
with to the 1500lbf size we were looking at. When we found that we
could make regeneratively cooled engines out of plain old aluminum
without too much trouble, we dropped the exotic material work.
Somewhat more complex plumbing, but much easier to fabricate and
scale.

The poster-child for exotic materials that I hope for is nanotube
composites allowing pressure fed SSTO designs with conventional
propellants.

John Carmack
www.armadilloaerospace.com
  #27  
Old July 13th 03, 11:33 PM
Henry Spencer
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Default Armadillo Aerospace drop test

In article ,
John Carmack wrote:
...opting for an ogive nose cone instead of a conical
one could quadruple the cost, or more, for very minor theoretical
gains...


And often you can do almost as well with a little cleverness. For this
particular example, a double cone (starting with a gentle taper and then
switching abruptly to a steeper one partway up) gets you most of the
benefit of an ogive without the fabrication difficulties.
--
MOST launched 1015 EDT 30 June, separated 1046, | Henry Spencer
first ground-station pass 1651, all nominal! |
  #28  
Old July 14th 03, 07:26 PM
jeff findley
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Default Armadillo Aerospace drop test

Earl Colby Pottinger writes:

Myself, would have to say "The key to a simpler but successful design is
build it cheap, test it and find the places where you need more expensive,
better-performing materials. " One of NASA's big problems was they tend to
build with only more expensive, better-performing materials.


I used to work with a programmer that had a NASA like philosophy when
it came to writing code. Got all worried about the performance of
lists that contained, at most, a few hundred entries of less than 1k
of data each, even though you'd only access those once per scenario.
Spent way too much time writing special purpose code to store the
things in a fast hash table instead of just sticking them in a simple
list.

Deeper in the scenario, there were lists that contained, at most, a
million entities, also less than 1k in size. Guess where most of the
CPU time was really spent? Guess where we really needed to work on
the code to increase performance?

Sometimes, making it "better" is a waste of time, effort, and money.

Jeff
--
Remove "no" and "spam" from email address to reply.
If it says "This is not spam!", it's surely a lie.
  #29  
Old July 15th 03, 12:51 AM
sanman
external usenet poster
 
Posts: n/a
Default Armadillo Aerospace drop test

(John Carmack) wrote in message . com...
All we need is a little more bracing in a couple places, no big deal.

There are Really Large benefits to working with relatively low
strength aluminum for development projects. You can weld handles on,
grind them off, drill holes all over the place, then fill them back
in, and it doesn't really effect the strength of the design. If you
started with a highly optimized alloy or composite system you could
save weight, but every modification would impact the design. High
tech composites often don't like random holes being punched in them,
and strong metals usually can't be welded without ruining the heat
treatment.


Well, I'd read about foamed metals being investigated by the big
automakers for bumpers with better impact-absorption. Apparently,
foamed metal can absorb impact energy better due to what they call
"cell collapse" effect.
Since a cone is a simple shape, have you considered taking an
off-the-shelf cylindrical stock-shape made out of foamed aluminum, and
machining it into the cone shape for your crush cone? Consider that
foamed metal parts are significantly lighter, and are easily machined.
I've also read it has excellent electromagnetic shielding properties,
which can protect whatever computer crap you have on the inside.

http://www.itc-g.com/IPM/FA.htm
http://www.mb2010.com/research/foamed_metals.html


It was also rather surprising how much cheaper rolled aluminum
construction was. For complex curves like airfoils, composites are
often cheaper to fabricate, but if your design can be built with just
sheet metal brake and roll work, it is much cheaper, because the final
product is completely self supporting during fabrication. There is a
good lesson here -- opting for an ogive nose cone instead of a conical
one could quadruple the cost, or more, for very minor theoretical
gains. Fabrication difficulties are easy to overlook when making
clean sheet designs.


Gee, since your computer-heavy reputation is well-known, I'd assumed
your efforts were very CAD-intensive. Is the prototyping all being
done in the workshop? What are you doing in the way of CAD, or even
flight dynamics simulation?

The basic idea of using exotic materials to simplify the rest of the
design has a lot of merit, but we haven't hit on a poster-child case
for it yet. I spent a good chunk of money researching radiatively
cooled engines of exotic construction: TZM (moly alloy) base with a
disilicide oxidation protection coating, sealed to the injector with a
silver plated, nitrogen pressurized metalic O-ring. It was very
simple, and it worked, but it cost a LOT, and there were unanswered
fabrication questions in scaling it up from the 50lbf size we tested
with to the 1500lbf size we were looking at. When we found that we
could make regeneratively cooled engines out of plain old aluminum
without too much trouble, we dropped the exotic material work.
Somewhat more complex plumbing, but much easier to fabricate and
scale.

The poster-child for exotic materials that I hope for is nanotube
composites allowing pressure fed SSTO designs with conventional
propellants.

John Carmack
www.armadilloaerospace.com


Yeah, the nanotube stuff will be the coolest once it comes out.
Hopefully that would be available in 10 years time. Apparently, some
guy came out with a simple dipping method that could be used to build
a laminate structure (perhaps a spaceship hull?). All you'd need is a
vat with your nanotube solution and a vat with polymer resin. The only
problem is the availability of the blessed nanotubes.

http://www.nature.com/nsu/021007/021007-13.html

Probably stuff you'd already heard about, but just food for your
thought anyway.
Maybe if you stay in the rocket business, you can eventually
incorporate this stuff in v4.0!
 




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