Lunar Base discussion "why, what for etc" (long)
Alan Erskine
why?":
"Four levels of questions must be answered in the affirmative at the
national level within the political process before substantive discussions
of lunar bases make any sense. First, should the United States have a space
program? (If so, why?) Second, does human spaceflight have any role in the
U.S. space program? (If so, what?) Third, does the regime of human
spaceflight extend beyond transient visits to low Earth orbit? (If so, for
what purpose?) Is permanent human presence in the solar system beyond the
Earth a reasonable goal for the world's space programs within the time frame
defined by our present technological horizons? (If so, what sort of
objectives and schedule should we set for ourselves?)
My answers:
1 - yes, the U.S. should have a space program, but not for simple political
reasons. NASA needs to be 'redirected' (forced, if you wish) back into the
policy and tasks it performed in the days of NACA, that is, research,
development, engineering etc, not actually performing launches, or setting
up space stations, Moon bases etc. I believe that precursor commercial
programs, run, or at least funded by the 'space faring' governments is the
most economical method of attaining permanent human presence 'off Earth'.
Perhaps the U.S. program should be opened up to the rest of the world?
Seeing the United States has all the facilities, experts, and most of the
equipment for just about anything to do with space, maybe the U.S. should
enter into deals on a more commercial basis that has been the case in the
past.
2 - Yes, Human spaceflight has a place in the U.S. space program. It is
important to explore, test and learn. The best way of doing this is to go
and see what it is like in that location. This applies for the Moon, Mars
and the rest of space. Humans have been exploring for 35,000 years - since
humanity in its current form developed. We can't stop just because this
planet has been explored to the nth degree.
3 - see point '2'.
4 - What is the point of having a 'space program' if people are not to
benefit from the experience? People didn't benefit from the exploration of
Australia for over a century, even though Europeans settled (mostly by
force) here in the 1780's. Wool was the first export, but that has grown
considerably over the last two centuries. In other words, not only is a
permanent human presence in the Solar System be the main goal of the worlds
space powers, it is absolutely vital to the continued survival of the human
species.
What are your answers to the questions posed by Wendell Mendell?
In the same paper, Wendell Mendell states that there must be concesus on a
national level as to what the 'space program' is to be. Remember this if
you decide to answer Mr Mendells questions.
Although my answers are not as well formulated as I would have liked, it is
hard to explain in technical terms what I _feel_. In other words, emotional
responses tend to cloud reality.
Yours sincerely
Alan Erskine
alane...@optusnet.com.au
Michael R. Irwin
The U.S. government has demonstrated little ability to effectively
manage commercial activities effectively. The U.S.G. is designed
to govern and it should restrict itself to that function. R&D is
a proven beneficial activity when the advances are place fairly in
the "commons" or public domain for any to use on an equal footing.
Infrastructure is acceptable. Commerce is not, it turns into a
behometh/agency partnership that is decidedly destructive of personal
liberites the U.S.G. is tasked with protecting.
>
> 2 - Yes, Human spaceflight has a place in the U.S. space program. It is
> important to explore, test and learn. The best way of doing this is to go
> and see what it is like in that location. This applies for the Moon, Mars
> and the rest of space. Humans have been exploring for 35,000 years - since
> humanity in its current form developed. We can't stop just because this
> planet has been explored to the nth degree.
Personally I would rather be sending out volunteers as explorer
teams instead of locking up rebellious drug users. Likewise a
myriad of other beneficial human pursuits. I agree with you.
I would state it as: Human beings do not stagnate as fast as
totalitarian
social structures and when restraints get too restrictive or opportunity
uncommonly, unfairly, or infrequently distributed to emerging
individuals there is large trouble brewing.
>
> 3 - see point '2'.
I do not really follow his question. If one accepts the tenet
that exploration a human trait desirable to fullfill then
articially defining regimes makes little sense. The question
becomes one of feasibility. Not "should" we explore but
"Can we explore with the available resources and is it more
desirable than an alternate use of the resources?".
>
> 4 - What is the point of having a 'space program' if people are not to
> benefit from the experience? People didn't benefit from the exploration of
> Australia for over a century, even though Europeans settled (mostly by
> force) here in the 1780's. Wool was the first export, but that has grown
> considerably over the last two centuries. In other words, not only is a
> permanent human presence in the Solar System be the main goal of the worlds
> space powers, it is absolutely vital to the continued survival of the human
> species.
The point of having a space program is to project government
out timely to keep up with citizens exploring space. Until
we get off our ass and do something as individuals and associations
of free sovereign individuals there is little point in NASA extending
their domain beyond their current status.
>
> What are your answers to the questions posed by Wendell Mendell?
>
> In the same paper, Wendell Mendell states that there must be concesus on a
> national level as to what the 'space program' is to be. Remember this if
> you decide to answer Mr Mendells questions.
I disagree. If we decide that only a national size association
of people can apply the resources necessary to get the job done
then clearly there must be consensus at the national level. If
sub associations of citizens assemble the resources to begin
activities then no national consensus beyond an appropriate set
of minimal regulatory provisions and means to monitor and enforce
them is required.
For example: Cheap private RLVs and Lunar Settlement raise the
possibilty of orbital bombardment by rocks. A U.S. national
consensus must then be reached on how to provide for the "common
defense" if possible. A few U.S. military outposts in space
are not hard to visualize as a means of intervention is designed
to interdict falling rocks. Notice that they followed the settlers to
meet their responsibilities. They did not pioneer the way in
this scenario.
Regards,
Mike Irwin
Henry Spencer
Michael R. Irwin <mir...@harborside.com> wrote:
>For example: Cheap private RLVs and Lunar Settlement raise the
>possibilty of orbital bombardment by rocks.
It's a false terror. The catapult needed to get substantial rocks off the
Moon is a tremendous investment, and very vulnerable to attack. Heinlein
didn't do his numbers carefully enough. Earth's gravity acts as an energy
amplifier, but the amplification ratio isn't huge, and if you want to
produce a major impact, the initial energy investment is massive. Nuclear
missiles are a more cost-effective (and more easily hidden) weapon, unless
you end up needing huge numbers of them for some reason.
--
When failure is not an option, success | Henry Spencer he...@spsystems.net
can get expensive. -- Peter Stibrany | (aka he...@zoo.toronto.edu)
Robert Mockan
"Michael R. Irwin" wrote:
>
> Alan Erskine wrote:
(snipped Alans' remarks. RM)
> >
> I disagree. If we decide that only a national size association
> of people can apply the resources necessary to get the job done
> then clearly there must be consensus at the national level. If
> sub associations of citizens assemble the resources to begin
> activities then no national consensus beyond an appropriate set
> of minimal regulatory provisions and means to monitor and enforce
> them is required.
>
> For example: Cheap private RLVs and Lunar Settlement raise the
> possibilty of orbital bombardment by rocks. A U.S. national
> consensus must then be reached on how to provide for the "common
> defense" if possible. A few U.S. military outposts in space
> are not hard to visualize as a means of intervention is designed
> to interdict falling rocks. Notice that they followed the settlers to
> meet their responsibilities. They did not pioneer the way in
> this scenario.
>
> Regards,
> Mike Irwin
-----------------
At an ultra light airfield not far from where I live anyone can try to
fly any aircraft below given weight limits and fuel capacity. You see
all sorts of designs. The place corresponds to your first paragraph
above, but for ultra lights rather than unlimited class rockets.
IF a launch site were provided free of regulatory obstacles concerning
fabrication, fueling, and so on (but perhaps with engineer design
approval and sign-off..and tracking facilities, after all rocket science
isn't everyone's bread and butter) can there be any doubt that we could
have a vibrant "hobby" space program? Design level to Mercury sub orbital
certainly, and manned capsule orbital for the ambitious. Even WW2 era V-2
rocket technology could provide that. All liability considerations would
have to be dis-allowed, since there would probably be a good number of
body bags needed.. but what you are saying I think is still a good idea.
Let people who want to build their rockets do so, and after a falling
out of poor designs (boom, falling debris, scratch that design!) fewer
failures could be expected. It would mean objectors who have a problem
with individuals accepting responsibility for their own actions would have
to shut up and not try to prohibit progress, but that has happened before.
At the ultra light field the least cost way of fun flying is a motorized
hang glider. Saw a fellow launch from top Mt. Shasta few years ago. He
carted it up South Slope during the summer, and took off from the peak.
When he got over Shasta City still way up.
He wasn't competing with a national effort to fly a hang glider from the
top of a mountain. He did it for fun. A "hobby" space program could lead
to a low cost lunar base or Mars ship.. but NOT with government or the
"experts" supposing it can't or shouldn't be done. If people who object
would just stay out of the way, the people who want to do it could, and
would, do it. (be great if one had access to nuclear fuel.. but maybe
have to wait for that Space Force you allude to in your second paragraph).
Probably the most serious accident I've seen at the ultra light field
was a one man jet helicopter when an engine came off and hit a bystander.
Not dead but blood all over (crack, flying engine, scratch THAT design!).
No doubt anyone can come up with countless reasons not to do any of this,
and more reasons to object to anyone else doing any of this.
To all those, just one thing to say. You are the only real problem, and the
only real obstacle, preventing any of this from happening. It is not a
technology problem, not a money problem. It IS regulations, government
interference, politics, and so on.
Regards, R. Mockan.
Regards, R. Mockan.
Michael R. Irwin
I shall have to word this carefully or somebody is going
to dare me to do the homework, assuming energy is cheap. :)
Heinlein did not propose the catapult as a cost effective
weapons system deployment. He postulated a catapult in
steady commercial operation providing a mature technology
base in an emergency. (as Henry undoubtedly knows, ref.
for convenience of other readers: lunar revolution against
despotic U.N. tryanny. Title: "The Moon is a Harsh Mistress",
enjoyable reading if you have libertarian tendencies or enjoy
"hard" science fiction)
From this base of mature technology and experience his
fictional characters built a secret catapult. He agreed
with you that system would be fragile and easily disabled.
One nuke and it was over.
I have no idea how accurately modern radars and telescopes
could backtrack an incoming rock. Presumably a system
launching from the far side and maneuvering a bit out of
the catapult could confuse things a bit. Obviously the
lunar launch authority would have to keep it "skies" clear
of recon satellites for this to work.
In my view a large lunar settlement or nation is likely to
have a catapult in commercial operation. When the Lunar
Defense department begins it contemplation of defenses I
think it likely a tradeoff study between using the commercial
catapults and defending them vs. a nuclear military force as
you suggest is likely.
I agree it is likely they will reach the same conclusions you
and Heinlein reached. A catapult is a fragile expensive
system better left to launching commercial payloads while
military professionals staff dedicated military systems.
May our RLVs use you as a reference when filing Mr. Bassior's
required flight plans with U.S. orbital control and DOD for
lunar settlement destinations? :)
Regards,
Mike Irwin
Jim Kingdon
> space program?
Well, in a certain sense we have that - ERPS (here in California), the
Huntsville balloon carried rocket people, &c.
It isn't clear how readily those activities can scale to orbit. Just
as a random anecdote, I heard some amusing stories from some ERPS
people about driving 100s of miles looking for their payload. Only to
find that it had gone further away than they figured was worth
bothering to look. Granted this was a balloon carried rocket and
other designs wouldn't have that particular problem, but there is
tracking and such.
Now having said that, there are a lot of wonderful amateur rocket
people doing interesting things, and they deserve our support and
admiration.
Jordan S. Bassior
>I agree it is likely they will reach the same conclusions you
>and Heinlein reached. A catapult is a fragile expensive
>system better left to launching commercial payloads while
>military professionals staff dedicated military systems.
Nuclear missiles, however, are easier to intercept than kinetic missiles.
>May our RLVs use you as a reference when filing Mr. Bassior's
>required flight plans with U.S. orbital control and DOD for
>lunar settlement destinations? :)
I never stated that spaceships should be required to file flight plans with
"U.S. orbital command." Please apologize for incorrectly stating that I did.
--
Sincerely Yours,
Jordan
--
"To urge the preparation of defence is not to assert the imminence of war. On
the contrary, if war were imminent, preparations for defense would be too
late." (Churchill, 1934)
--
Michael R. Irwin
"Jordan S. Bassior" wrote:
>
> Michael R. Irwin said:
>
> ?I agree it is likely they will reach the same conclusions you
> ?and Heinlein reached. A catapult is a fragile expensive
> ?system better left to launching commercial payloads while
> ?military professionals staff dedicated military systems.
>
> Nuclear missiles, however, are easier to intercept than kinetic missiles.
With existing systems or postulated ones? Either way this would
be an interesting paper or thesis to read.
>
> ?May our RLVs use you as a reference when filing Mr. Bassior's
> ?required flight plans with U.S. orbital control and DOD for
> ?lunar settlement destinations? :)
>
> I never stated that spaceships should be required to file flight plans with
> "U.S. orbital command." Please apologize for incorrectly stating that I did.
Much chastened, I apologize profusely and abjectly for stating that
the proposed recipient of the flight plans; required by your proposed
"Blastem theory of operations" (to avoid sure destruction by fallible
but useful U.S. NMD) to avoid looking like a suspicious terrorist
controlled RLV launched on orbital trajectory; is a non existent
U.S. organization.
I hope Carnivore does not mention this indiscretion to Space Command.
Wait a minute!
I never said you said your required flight plans
had to be filed with U.S. Orbital Command! I asked if our RLVs
could use Henry as a reference when filing the allegedly (by you!)
required flight plans with U.S. orbital control. Lower case to
indicate that it might be a function rather than the specific
name of a specific organization and therefore not capitilized
even as a patriotic I chose to recognize the name of a proper
place like the U.S. with capital letters.
Please apologize for lying like that and tricking me out of an
abject profuse apology!
Regards,
Mike Irwin
Jordan S. Bassior
>With existing systems or postulated ones?
_Both_, actually, since even the Patriot III has marginal capability against an
ICBM, but _no_ capability against a massive KKV. Incidentally, since lunar
catapults, and for that matter _all_ massive KKV's, are "postulated" systems,
comparing their capabilities to other postulated systems likely to be available
in the same time frame is perfectly reasonable projection.
Henry Spencer
Jordan S. Bassior <jsba...@aol.com> wrote:
>>I agree it is likely they will reach the same conclusions you
>>and Heinlein reached. A catapult is a fragile expensive
>>system better left to launching commercial payloads while
>>military professionals staff dedicated military systems.
>
>Nuclear missiles, however, are easier to intercept than kinetic missiles.
They are, however, considerably harder to spot, being much smaller and
more amenable to stealth technologies.
Henry Spencer
Michael R. Irwin <mir...@harborside.com> wrote:
>From this base of mature technology and experience his
>fictional characters built a secret catapult. He agreed
>with you that system would be fragile and easily disabled.
>One nuke and it was over.
Yep. And he blithely waved away the question of how it was *powered*.
(And also what happened to the waste heat from the power supply, a
question of some importance since warships will surely have thermal-
infrared scanners.)
It's not clear that building such a catapult, *and its power supply*,
and hiding them effectively is any easier than making nuclear weapons.
>May our RLVs use you as a reference when filing Mr. Bassior's
>required flight plans with U.S. orbital control and DOD for
>lunar settlement destinations? :)
Feel free, but remember that I'm an evil Canadian spy, and consider
whether you really *want* me as a reference. :-)
Jordan S. Bassior
>They are, however, considerably harder to spot, being much smaller and
>more amenable to stealth technologies.
Well yes, but being able to spot something does one little good if one can't
intercept it.
Henry Spencer
>>more amenable to stealth technologies.
>
>Well yes, but being able to spot something does one little good if one can't
>intercept it.
The converse is also true; the ability to intercept something you don't
see until too late does little good.
Also, it has just occurred to me that RAH missed another little problem,
one that may not have been understood at the time. It takes quite a large
rock to reach the ground *intact*; stony meteorites mostly explode high in
the atmosphere, because they aren't strong enough to hold together as drag
forces grow rapidly. A thin steel casing might not help all that much --
I'm not sure offhand -- and all your interceptor really has to do is to
split the casing open, and the atmosphere will do the rest.
Jordan S. Bassior
>In article <20010414103728...@ng-cu1.aol.com>,
>Jordan S. Bassior <jsba...@aol.com> wrote:
>
>>>They are, however, considerably harder to spot, being much smaller and
>>>more amenable to stealth technologies.
>>
>>Well yes, but being able to spot something does one little good if one can't
>>intercept it.
>
>The converse is also true; the ability to intercept something you don't
>see until too late does little good.
Well, yes ... but by c. 1960 we _already_ had the tech to reliably detect
ICBM's.
You could postulate a stealthed ICBM, of course, but stealth doesn't work as
well when you don't have ground clutter to help one. It also doesn't work as
well when one is travelling super- let alone hypersonic (due to thermal glow).
(admittedly, in _space_ there's no thermal glow until you get into the RKV
range of speeds!)
>Also, it has just occurred to me that RAH missed another little problem,
>one that may not have been understood at the time. It takes quite a large
>rock to reach the ground *intact*; stony meteorites mostly explode high in
>the atmosphere, because they aren't strong enough to hold together as drag
>forces grow rapidly. A thin steel casing might not help all that much --
>I'm not sure offhand -- and all your interceptor really has to do is to
>split the casing open, and the atmosphere will do the rest.
That's a very good point. In my sf-nal universes, when I postulated asteroidal
KKV's, I assumed they were _big_ (kilometers in diameter) for that very reason.
Michael R. Irwin
"Jordan S. Bassior" wrote:
>
> Michael R. Irwin said:
>
> >With existing systems or postulated ones?
>
> _Both_, actually, since even the Patriot III has marginal capability against an
> ICBM, but _no_ capability against a massive KKV. Incidentally, since lunar
> catapults, and for that matter _all_ massive KKV's, are "postulated" systems,
> comparing their capabilities to other postulated systems likely to be available
> in the same time frame is perfectly reasonable projection.
>
You forgot to return my apology for your "lying" and scurillous
proclivities to selective quotes and context snipping under
convenient posturing of trimming courtesies.
When an internet principal shows up you are in really
really big trouble. Just wait, you will see. :)
Regards,
Mike Irwin
Michael R. Irwin
Henry Spencer wrote:
>
> In article <20010414103728...@ng-cu1.aol.com>,
> Jordan S. Bassior <jsba...@aol.com> wrote:
> >>They are, however, considerably harder to spot, being much smaller and
> >>more amenable to stealth technologies.
> >
> >Well yes, but being able to spot something does one little good if one can't
> >intercept it.
>
> The converse is also true; the ability to intercept something you don't
> see until too late does little good.
>
> Also, it has just occurred to me that RAH missed another little problem,
> one that may not have been understood at the time. It takes quite a large
> rock to reach the ground *intact*; stony meteorites mostly explode high in
> the atmosphere, because they aren't strong enough to hold together as drag
> forces grow rapidly. A thin steel casing might not help all that much --
> I'm not sure offhand -- and all your interceptor really has to do is to
> split the casing open, and the atmosphere will do the rest.
Heinlein was highly supportive of adaptibility in
response to reality.
Had the physics been better known perhaps he would
have advocated bundles of crowbars. Optimizing
separation altitudes would be tricky. Perhaps
empirical methods would be applicable.
Regards
Mike Irwin
Michael R. Irwin
Henry Spencer wrote:
>
> In article <3AD67984...@harborside.com>,
> Michael R. Irwin <mir...@harborside.com> wrote:
<Unfortunate engineering details.>
> >May our RLVs use you as a reference when filing Mr. Bassior's
> >required flight plans with U.S. orbital control and DOD for
> >lunar settlement destinations? :)
>
> Feel free, but remember that I'm an evil Canadian spy, and consider
> whether you really *want* me as a reference. :-)
True. I tried to ship a locally surplus 3DSMax license to
New Zealand for a project about a year ago.
Apparently ANZUZ signatories other than the U.S. are also
feared as threats to the "free world".
What possible use network distributed processing of animation
frames would be to totalitarian or "Terrorist" states or
organizations with agents in New Zealand or Australia was
left as an excercise to the offending sovereign. I still
have not figured it out.
Why would U.S. opponents start a nefarious project by purchasing
or stealing U.S. commercial binaries when source code much easier
to modify is freely available on the internet?
This is a problem our open engineering crowd (should it
materialize) will have to address in our business models.
I suspect it leads to U.S. only teams and
international efforts based exclusively outside of U.S.
soil or territories.
Regards,
Mike Irwin
Jordan S. Bassior
>You forgot to return my apology for your "lying" and scurillous
>proclivities to selective quotes and context snipping under
>convenient posturing of trimming courtesies.
Um, what?
Josh Hopkins
>
> In article <20010414103728...@ng-cu1.aol.com>,
> Jordan S. Bassior <jsba...@aol.com> wrote:
> >>They are, however, considerably harder to spot, being much smaller and
> >>more amenable to stealth technologies.
> >
> >Well yes, but being able to spot something does one little good if one can't
> >intercept it.
>
> The converse is also true; the ability to intercept something you don't
> see until too late does little good.
>
> Also, it has just occurred to me that RAH missed another little problem,
> one that may not have been understood at the time. It takes quite a large
> rock to reach the ground *intact*; stony meteorites mostly explode high in
> the atmosphere, because they aren't strong enough to hold together as drag
> forces grow rapidly.
Yes, indeed this is probably the largest problem with lunar
rock-throwing. The Earth's atmosphere works as quite good
anti-space-rock armor. The minimum size for dangerous rocks is on the
order of house-sized, and really effective military rocks would need to
be even bigger. In contrast, any surface lunar facilities are
essentialy unprotected, and could be destroyed with quite small
projectiles. It is therefore almost certainly easier to destroy lunar
facilities with Earth-launched rocks than the other way around, despite
the Moon's energy advantage. And any angry Earthers aren't going to
limit themeselves to rocks. The Moon as a military high-ground is not a
particularly plausible scenario.
Josh Hopkins.
Henry Spencer
Jordan S. Bassior <jsba...@aol.com> wrote:
>>>>They are, however, considerably harder to spot, being much smaller and
>
>Well, yes ... but by c. 1960 we _already_ had the tech to reliably detect
>ICBM's.
At short distances, with some other caveats.
>You could postulate a stealthed ICBM, of course, but stealth doesn't work as
>well when you don't have ground clutter to help one. It also doesn't work as
>well when one is travelling super- let alone hypersonic (due to thermal glow).
>(admittedly, in _space_ there's no thermal glow until you get into the RKV
>range of speeds!)
Right. It's hard to stealth an ICBM, but an IPBM is another matter. Just
a flat sheet of aluminum foil, maybe with a suitable backside coating to
keep it cold, held out front at an angle, would make detection seriously
difficult.
Jordan S. Bassior
>Right. It's hard to stealth an ICBM, but an IPBM is another matter. Just
>a flat sheet of aluminum foil, maybe with a suitable backside coating to
>keep it cold, held out front at an angle, would make detection seriously
>difficult.
Something like that, yes. Important points in space "stealth" ...
1) Don't radiate _anything_ towards your target. Any maneuvering jets had
better be either very directional, or cold thruster types such as
compressed-gas.
2) It works best at longer ranges, like any other stealthing. And also, it's
relative to the amount of power which can be put into an active search sweep.
3) It would work on KKV's too -- but of course the bigger the KKV _especially
in silhouette_, the greater the range at which it will be detected, and
4) Eventually, the IPBM will be detected, once it gets close enough to the
radar. Whether that gives the defender enough time or not depends strongly on
scenario assumptions.
Roy Hulen Stogner
>Also, it has just occurred to me that RAH missed another little problem,
>one that may not have been understood at the time. It takes quite a large
>rock to reach the ground *intact*; stony meteorites mostly explode high in
>the atmosphere, because they aren't strong enough to hold together as drag
>forces grow rapidly. A thin steel casing might not help all that much --
>I'm not sure offhand -- and all your interceptor really has to do is to
>split the casing open, and the atmosphere will do the rest.
IIRC, the casings used for "throwing rocks" were the same ones used
for throwing food shipments, and so were probably designed with
reentry heat shielding and a nice wide safety factor. Replacing the
casing cargo with much denser rock would probably slim down that
margin... but then again if the "rock" went through any refinement it
could add structural integrity to the casing itself.
And interceptors needn't apply; for every 2 interceptors that turned
the projectile into an exploding dust cloud, you could have a third
that simply redirected fragments of it from their unpopulated targets
into the middle of a populated area.
I think it's worth giving Heinlein a little leeway here; I suspect if
you listed all the questionable parts of that book, "economical lunar
food production" would be far above "reentry vehicles repurposed for
kinetic kill".
---
Roy Stogner
Jordan S. Bassior
>And interceptors needn't apply; for every 2 interceptors that turned
>the projectile into an exploding dust cloud, you could have a third
>that simply redirected fragments of it from their unpopulated targets
>into the middle of a populated area.
If the interceptor hit it _before_ re-entry, the "fragments" would mostly burn
up in the atmosphere.
Michael R. Irwin
"Jordan S. Bassior" wrote:
>
> Michael R. Irwin said:
>
> >You forgot to return my apology for your "lying" and scurillous
> >proclivities to selective quotes and context snipping under
> >convenient posturing of trimming courtesies.
>
> Um, what?
>
Start quote previous thread material:
I said:
> ?May our RLVs use you as a reference when filing Mr. Bassior's
> ?required flight plans with U.S. orbital control and DOD for
> ?lunar settlement destinations? :)
You (or a poster simulating your name and email address) said:
>
> I never stated that spaceships should be required to file flight plans with
> "U.S. orbital command." Please apologize for incorrectly stating that I did.
Much chastened, I apologize profusely and abjectly for stating that
the proposed recipient of the flight plans; required by your proposed
"Blastem theory of operations" (to avoid sure destruction by fallible
but useful U.S. NMD) to avoid looking like a suspicious terrorist
controlled RLV launched on orbital trajectory; is a non existent
U.S. organization.
I hope Carnivore does not mention this indiscretion to Space Command.
Wait a minute!
I never said you said your required flight plans
had to be filed with U.S. Orbital Command! I asked if our RLVs
could use Henry as a reference when filing the allegedly (by you!)
required flight plans with U.S. orbital control. Lower case to
indicate that it might be a function rather than the specific
name of a specific organization and therefore not capitilized
even as a patriotic I chose to recognize the name of a proper
place like the U.S. with capital letters.
Please apologize for lying like that and tricking me out of an
abject profuse apology!
End Quote of previous thread content.
Hope that was helpful repetition. My server
seems to be dropping an occasional message in various
threads as well.
Regards,
Mike Irwin
Jordan S. Bassior
whatever it is, ok?
Doug Jones
>
> On Sat, 14 Apr 2001 16:27:40 GMT, Henry Spencer wrote:
>
> >Also, it has just occurred to me that RAH missed another little problem,
> >one that may not have been understood at the time. It takes quite a large
> >rock to reach the ground *intact*; stony meteorites mostly explode high in
> >the atmosphere, because they aren't strong enough to hold together as drag
> >forces grow rapidly. A thin steel casing might not help all that much --
> >I'm not sure offhand -- and all your interceptor really has to do is to
> >split the casing open, and the atmosphere will do the rest.
>
> IIRC, the casings used for "throwing rocks" were the same ones used
> for throwing food shipments, and so were probably designed with
> reentry heat shielding and a nice wide safety factor. Replacing the
> casing cargo with much denser rock would probably slim down that
> margin... but then again if the "rock" went through any refinement it
> could add structural integrity to the casing itself.
Those casings would be designed as decelerators for a shallow atmosphere
entry, to deliver an intact payload at low velocity. The peak gees
would be no more than ten at very high altitude, and the thermal
protection would be just enough for the task.
A steep impact trajectory would plunge into denser air *very* quickly,
easily reaching 200-300 gee acceleration. A lightweight casing intended
for landing low density payload would fail long before impact, resulting
in fireworks & thunder but little damage.
The most effective kinetic warhead against soft targets would likely be
an array of steel darts with ablative coatings, spreading out to produce
a shotgun-like blast instead of a single overkilled crater.
> And interceptors needn't apply; for every 2 interceptors that turned
> the projectile into an exploding dust cloud, you could have a third
> that simply redirected fragments of it from their unpopulated targets
> into the middle of a populated area.
Only if the projectile is a chunk of steel- an unreinforced hundred ton
rock would not be strong enough to survive the airloads.
> I think it's worth giving Heinlein a little leeway here; I suspect if
> you listed all the questionable parts of that book, "economical lunar
> food production" would be far above "reentry vehicles repurposed for
> kinetic kill".
The phrase "Shipping coal to Newscastle" springs to mind...
--
Doug Jones
Rocket Plumber, XCOR Aerospace
http://www.xcor.com
Paul F. Dietz
> > I think it's worth giving Heinlein a little leeway here; I suspect if
> > you listed all the questionable parts of that book, "economical lunar
> > food production" would be far above "reentry vehicles repurposed for
> > kinetic kill".
>
> The phrase "Shipping coal to Newscastle" springs to mind...
Heinlein had bought into the 'food is going to be scarce
because of overpopulation' hysteria.
Paul
Michael R. Irwin
"Jordan S. Bassior" wrote:
>
> Mike, I have literally no idea what you're upset about, but I apologize for
> whatever it is, ok?
Ok. We have a misunderstanding.
For that I sincerely apologize as well, Jordan.
I did not intend to convey that I was upset
or that you had offended me. Neither of which
is the case, at least not beyond normal usenet usage.
I did not view my liberties with "orbital control" as
large in the usenet scheme of things and was rather
amused by the request for apology.
My attempt at humerous/sarcastic response got a bit out
of hand.
I look forward to future discussions but I am
a bit played out on NMD at the moment. For what
it is worth I view defense as better than offense
as defense, but given our starting conditions it is
a complex subject complicated by a lot of factors:
technical, political, economic, domestic, and abroad.
I respect your efforts to clarify a reasonable
majority view leading to effective deployment.
I.E. Comprehensive layered defenses which are
reliable enough to be useful and cost effective
to maintain and operate continuously.
High Regards,
Mike Irwin
George William Herbert
>The most effective kinetic warhead against soft targets would likely be
>an array of steel darts with ablative coatings, spreading out to produce
>a shotgun-like blast instead of a single overkilled crater.
This turns out to be hellishly difficult to optimize, though.
You want the darts to arrive on target with maximum velocity
and thus KE, but first the cluster container then the darts
themselves will lose energy to drag on the way down.
The cluster container will have a better ballistic coeficient
than the darts ( l^3/l^2 effect where the container has less
surface area per unit volume). But dispersing the darts with
enough sideways velocity (and uniformly enough) to make a good
pattern on impact is pretty tricky, too, so you need to disperse
at a goodly altitude.
If you have arbitrary materials available, then you may well want
to use DU or tungsten rather than steel. Increased density equals
higher ballistic coeficient, especially when it counts at the bottom.
They also both handle high temperatures better than steel will.
I keep coming back to cone-shaped darts, with just enough of a dimple
in the back to make sure hypersonic CP is behind CG, and just big
enough to minimize drag losses and ablation in the last km or so.
You may well end up wanting to multi-stage the cluster deployment,
say with seven conical subcarriers packed into a conical main
cluster carrier, deploying at say 10 km altitude with aerodynamic
shaping to achive say around a hundred meter seperation, then the
subcarriers releasing the darts explosively (embed them in a medium
velocity, low Pdet explosive, with typical Vlateral of 500 m/s)
at a km altitude or so, total pattern size around 300 m diameter
and typical velocity loss in the final km of on the order of 500 m/s
for hundred-gram projectiles and final impact velocity of around
3 km/s (KE of around 500 kJ; enough to penetrate the top of a tank,
or impact energy equivalent to a hand grenade detonating, though
with much less effective fragmentation). At a saturation of 1/10 m^2,
that's roughly two hits per vehicle in the target zone, an average
distance between impacts of around 10 feet to ensure good AP coverage
of the impact blast effects, and each cluster unit covers a circle
about 300 meters around, weighing around 1.5 to 2 tons prior to
atmospheric entry...
If you try smaller darts, they ablate and decellerate worse in the
final km of descent, so either you have to use more subclusters
or accept much less performance for a given weight of payload.
I suspect that hundred gram darts are roughly optimal for the sort
of target range we currently used combined effect clusterbombs for;
for truly soft targets it's probably a bit less than that.
-george william herbert
gher...@retro.com
Doug Jones
>
> Doug Jones <ran...@qnet.com> wrote:
> >The most effective kinetic warhead against soft targets would likely be
> >an array of steel darts with ablative coatings, spreading out to produce
> >a shotgun-like blast instead of a single overkilled crater.
>
> This turns out to be hellishly difficult to optimize, though.
> You want the darts to arrive on target with maximum velocity
> and thus KE, but first the cluster container then the darts
> themselves will lose energy to drag on the way down.
> The cluster container will have a better ballistic coeficient
> than the darts ( l^3/l^2 effect where the container has less
> surface area per unit volume). But dispersing the darts with
> enough sideways velocity (and uniformly enough) to make a good
> pattern on impact is pretty tricky, too, so you need to disperse
> at a goodly altitude.
3 km/s seems rather low for an object initially entering at escape
velocity or more, I presume your analysis is for a suborbital
earth-launched weapon?
> If you try smaller darts, they ablate and decellerate worse in the
> final km of descent, so either you have to use more subclusters
> or accept much less performance for a given weight of payload.
> I suspect that hundred gram darts are roughly optimal for the sort
> of target range we currently used combined effect clusterbombs for;
> for truly soft targets it's probably a bit less than that.
I agree on basically all your points; I mentioned steel only in the
context of an interplanetary attack where denser materials may be
scarce. The bizarre image comes to mind of an asteriod-based power
using platinum darts- first the KE weapons destroy the military targets,
and the looters digging up the remains finish the damage.
It'd just the thing for a major attack of werewolves, though, talk about
your silver bullets...
James Nicoll
Roy Hulen Stogner <roys...@owlnet.rice.edu> wrote:
snip
>And interceptors needn't apply; for every 2 interceptors that turned
>the projectile into an exploding dust cloud, you could have a third
>that simply redirected fragments of it from their unpopulated targets
>into the middle of a populated area.
>
Depends on the balance between farmland and cityscape in
the MIAHM setting, I think.
--
"Somehow I managed to get a job as an apprentice structural engineering
draughtsman, where I was supposed to design buildings which people would
sit in and the roof would not fall down and kill them. A big responsibility
for someone whose total education had come from PLANET STORIES." Bob Shaw