Missiles on the Moon: a credible threat?
Bruce Lewis
types. A hypothetical situation:
It is the year 201X, and you are President of the United States. For the last few
years, Nation X has been busy constructing its new moonbase, located at the
nearside equator not far from Tranquility Base. Recently, you have been
informed that the base is about to go operational and is now fully crewed.
Trouble! Your national security team brings you unsettling news: a hard-line
regime has taken control of the government of Nation X, and has announced
an economic boycott of U.S. goods. Since Nation X is one of the U.S.'s biggest
trading partners, the possibility of economic cris is real. Then, even more bad
news: image intel reports confirm that Nation X has removed the camouflage
over what can only be nuclear missile launchers near the lunar base. The
implied threat is there. Is it a credible one? Could the lunar base be used to
launch an attack on the United States? And what can be done to neutralize
the threat?
Mr. or Mme. President, what do you do next?
Bruce Lewis
Rick Ballard
threat potential. In addition to the lunar base being in a
very vulnerable and highly visible spot, unless the missiles
were very fast (i.e. very big), they would take about two days
to reach the earth. We're not talking about an ICBM, which can
strike a target 6000 miles away within a half an hour. An IPM
(InterPlanetary Missile) still has to obey the laws of orbital
mechanics, so you really can't "direct-fire" a missile at the
earth. I would think the long reaction time allowed the
potential target would permit a suitable defense (and response)
to be implemented.
Anyway, that's how I see it...
Later,
Rick Ballard
Sander Plomp
Launching an attack from the moon makes little sense. Due to the
distance the missiles would need a lot of time to reach the earth,
and their launch is easily observed. If you're going to threaten
someone, it's better to put the rockets close to the target - giving
the victim very little time to fight back. If the US is targeted, Cuba
is a nice place....
Can moon launched missles be intercepted? Unless there are specific
missle defense systems, not bloody likely. Depending on what will be
available in 201X, you might try to throw something in their path.
Send an unmanned spaceship on an interception course and blow it up
shortly before it meets the missles. The debris might damage or
destroy at least some of them. But let's face it, those who put those
misslies on the moon will have anticipated most defenses and if any of
them would be effective they wouldn't have bothered to put those
missles there. The warheads will have a little bit of steering
capabilitly - enough to avoid interception.
The best defense is probably a counter attack with earth based
missiles. Your retaliation will hit them before they hit you, so in a
particularly morbid way you've won. More importantly, you probaby have
much more time to evacuate cities and prepare for the blast, so your
survival rate will be much higher. Mind you, famine, exposure,
diseases and no-more-daytime-tv will make sure they don't survive
very long.
How long will those missles need to reach earth? Check the Apollo
missions (or go see Apollo 13) My guess would be that a moon-earth
trip takes about a day, and an earth-earth ICBM about 45 minutes.
Which would even give you the luxery of some negotiating/ultimatum
stuff before counter attacking.
So how seriously is the threat that moonbase makes. Well, they've
just moved (at great expense) some very dangerous missiles from
relatively nearby to very far away. Unless they also constructed
highways on the moon, those missiles are unlikely to go anywhere. It's
easy to take them out; just drop something on them. Anything capable
of reaching the moon will do, let's say an interplanetery probe you've
got lying around. Unless that base is armoured a few hundred kg of
mass making a hard landing is going to be very final.
Sorry. The most effective way to threaten a country with nuclear
attack is to smuggle the bombs into the country and hide them in the
cities. Finding all of them is impossible, they can be targeted very
accurately, and the panic that breaks out after the population becomes
aware that there are the bombs hidden is almost as effective as
detonating them.
Bob Ssmith
>I'm a fiction writer by trade, and I need a few quick answers from you technical
>types. A hypothetical situation:
>It is the year 201X, and you are President of the United States. For the last few
> years, Nation X has been busy constructing its new moonbase, located at the
> nearside equator not far from Tranquility Base. Recently, you have been
> informed that the base is about to go operational and is now fully crewed.
An equatorial base would be exposed to extreme variations of
temperature through each lunar "day." Better to locate the base
at one of the lunar poles, and dig it in deep enough to protect
it from high-energy radiation from the sun and from deep space.
A polar location would have the added advantage of being only a
short distance from being completely beyond the direct view of
the earth -- i.e., just a few kilometers over the polar horizon
from the earth -- and during the lunar night on the far side of
the moon, the base would be terrifically valuable as a site for
an observatory -- and also for clandestine manufacturing
operations.
>Trouble! Your national security team brings you unsettling news: a hard-line
> regime has taken control of the government of Nation X, and has announced
> an economic boycott of U.S. goods. Since Nation X is one of the U.S.'s biggest
> trading partners, the possibility of economic cris is real. Then, even more bad
> news: image intel reports confirm that Nation X has removed the camouflage
> over what can only be nuclear missile launchers near the lunar base. The
> implied threat is there. Is it a credible one? Could the lunar base be used to
> launch an attack on the United States? And what can be done to neutralize
> the threat?
Nation X would, of course, most plausibly be Japan --
though, conversely, it could be the US. In any case, lunar-
launched missiles could probably be built to cross the translunar
space in less than 8 hours -- or, at any rate, much faster than
could counterforce weapons from earth be launched to neutralize
the lunar missiles.
The question is, what motive would Nation X have for
launching a strike against the earth from the moon? During the
Cold War, the moon would have been a good basing site for the
US's MX missiles; on the moon, they could not have been construed
as first-strike weapons against the Soviet Union because, in the
time they would take to get to the earth, the Soviets could
launch their earth-based missiles against the US. Lunar-based
missiles would therefore be useful for two things:
retaliation/retribution and to hold the earth hostage for certain
goods that the lunar base might be dependent upon, such as water
(or, more simply, hydrogen). The threat of nuclear bombardment
seems to me not a plausible means by which to resolve a trade
dispute on earth.
An alternative to lunar-based missiles would be lunar-
based, solar-powered (or nuclear powered) MASERS which could
radiate huge amounts of coherent microwave energy into large
urban areas and overheat them within a matter of minutes, causing
massive death, even to people inside of buildings (unless the
buildings were shielded by metal coverings of the proper design).
Agricultural regions, even large ones, would also be subject to
massive damage from lunar-based directed-energy weapons.
>Mr. or Mme. President, what do you do next?
Dig and deep, and for good measure, kiss your ass goodbye . . .
>Bruce Lewis
Good luck, Bruce.
Bob Ssmith
Jason C Goodman
their tracking stations and their equivalent of Houston. Set 'em off.
Sit around and wait a week for the retaliatory strike from the moon to
get here, then make sure the "comsats" are in the way. Yawn.
If a preemptive retaliatory strike isn't your cup of tea (it isn't
mine), just wait. If they ever do launch those nukes, you've got a
week to put up the aforementioned antinuke satellites.
Even better, go out near the orbit of Jupiter, find yourself a
convenient asteroid, and "improve" its orbit a little. They'll never
know what hit 'em.
Conclusion: the moon's too far away from the action to be an
effective base. And _way_ too expensive.
Jim Glass ; JF ; GLASS ; x586-0375 ; (W) ; 634-000
|> I'm a fiction writer by trade, and I need a few quick answers from you technical
|> types. A hypothetical situation:
|>
|> It is the year 201X, and you are President of the United States. For the last few
|> years, Nation X has been busy constructing its new moonbase, located at the
|> nearside equator not far from Tranquility Base. Recently, you have been
|> informed that the base is about to go operational and is now fully crewed.
|>
|>
|> regime has taken control of the government of Nation X, and has announced
|> an economic boycott of U.S. goods. Since Nation X is one of the U.S.'s biggest
|> trading partners, the possibility of economic cris is real. Then, even more bad
|> news: image intel reports confirm that Nation X has removed the camouflage
|> over what can only be nuclear missile launchers near the lunar base. The
|> implied threat is there. Is it a credible one? Could the lunar base be used to
|> launch an attack on the United States? And what can be done to neutralize
|> the threat?
|>
|>
|>
|>
You read Robert Heinlein, "The Moon is a Harsh Mistress", for starters.
Credible threat? Uh huh.
Jim Glass
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Pat
Let's not also forget the massive economic costs of building a moon base,
haulling missiles up there and then tending to them. That would most likely
utterly bankrupt your opponent, giving you lots of opportunity to buy
his vital technologies on the market and leave them a doddering giant
like the soviets.
--
I learned something here today. Nothing I do and Nothing I own
can remake the past -- Buaku
Bruce Lewis
strike from "fast" (TOT<8 h.) missiles launched from a polar base would
be a credible threat to the United States. I appreciate the help, folks!
By the way, "Nation X" was completely hypothetical, and should not
be taken to represent any existing nation.
Bruce
Pop Culture Guru.
Bob Ssmith
Solar-powered or nuclear-powered directed-energy weapons based on the moon
could lay waste enormous amounts of territory on the earth's surface within
matters of minutes.
Bob Ssmith
Timothy Wu
: I would think a missile base on the moon would have a limited
Umm, why wouldn't Nation X, if it had some fettish/fixation on sending
warheads from space, just "drop" them from orbit? If a missile was fired
from the Moon, then the US could easily send many more earth-based nuclear
missiles to hit the enemy and then still have time to intercept the Xians'
moon-based ones.
Pat
Unless they can fly a trajectory in less then 20 minutes then they are
not a threat. 8 hours is more then enough time to launch a retaliation strike
that arrives long before the first strike.
Nope the real threat is depressed trajectory missiles launched from
submarines off the coast. 2-3 minutes, and no chance for a reaction.
William L. Goffe
: >I'm a fiction writer by trade, and I need a few quick answers from you technical
: >types. A hypothetical situation:
: >Trouble! Your national security team brings you unsettling news: a hard-line
: > regime has taken control of the government of Nation X, and has announced
: > an economic boycott of U.S. goods. Since Nation X is one of the U.S.'s biggest
: > trading partners, the possibility of economic cris is real. Then, even more bad
I'm not convinced that this part is credible. Such a trade embargo would
likely hurt their own nation more than us. Since the U.S. has the world's
largest economy, any such embargo would have a larger percentage impact on
them. It would be like a gun that fired backwards as well. Fiction aside,
history is not exactly replete with examples of this as an offensive threat.
The vast majority of embargos are used to isolate a relatively small economy:
South Africa, Hatai, Japan circa 1940, etc. The only offensive one I can think
of is the oil embargos of the 1970s.
.---. Bill Goffe bgo...@whale.st.usm.edu
( | Dept. of Econ. and International Business office: (601) 266-4484
)__*| University of Southern Mississippi fax: (601) 266-4920
(_| Southern Station, Box 5072
Hattiesburg, MS 39406-5072
Jeff Greason
>
>Unless they can fly a trajectory in less then 20 minutes then they are
>not a threat. 8 hours is more then enough time to launch a retaliation strike
>that arrives long before the first strike.
>
>Nope the real threat is depressed trajectory missiles launched from
>submarines off the coast. 2-3 minutes, and no chance for a reaction.
>
I think some of you are missing the point of a Lunar missile base.
Thinking from the lat 50's and early 60's was that the Lunar base makes
a great "second-strike" weapon, not first strike. So to use it in a
"threatening" mode, you have to have Earth-based weapons to back it
up.
So in a superpower confrontation, the psychology goes something like this:
Superpower "X" has a moon base, superpower "A" does not.
In a showdown, "X" can say "look, even if you nuke us, you lose; our
retailiatory strike from the Lunar base wipes you out. So why bother?"
Due to the long flight time, any attempt to preemptively strike the
Lunar base hasn't a prayer (if they're at all alert up there) -- they've
got days to see it coming and for the groundside power to react
appropriately.
It's a guaranteed second strike; enough to make anyone pause.
And, as a nice bonus, you get the option of non-nuclear weapons (kinetic
energy "rocks") to give you a range of responses available.
Disclaimer: While I am an Intel employee, all opinions expressed are my own,
and do not reflect the position of Intel, NETCOM, or Zippy the Pinhead.
============================================================================
Jeff Greason "We choose to go to the Moon in this decade,
<gre...@ptdcs2.intel.com> and do the other things, not because they
<gre...@ix.netcom.com> are easy, but because they are hard." -- JFK
Eric Pawtowski
Jim Glass ; JF ; GLASS ; x586-0375 ; (W) ; 634-000 <yqg...@sunshine.rockwell.com> wrote:
>
>You read Robert Heinlein, "The Moon is a Harsh Mistress", for starters.
>
>Credible threat? Uh huh.
That book was rather different, in that the lunar weapon was a mass
driver capable of throwing iron-wrapped rocks weighing hundreds of tons.
Much harder to intercept and destroy than a nuclear warhead. It also had
many, many, more shots than any concievable missile system could have.
The moon is unlikely to run out of rocks. The best defense against
*that* sort of threat is to take out the mass driver (which was tried
in the book, people can read it to see how it turned out).
Eric
--
epaw...@vt.edu----------------------------------------------------
Technicon 13 - SF&F return to SW Virginia! March 22-24, 1996.
Guests: Author L.E. Modesitt, Games designers Lori&Corey Cole,
Artist Ruth Thompson
Joseph Askew
>Solar-powered or nuclear-powered directed-energy weapons based on the moon
>could lay waste enormous amounts of territory on the earth's surface within
>matters of minutes.
Not to mention those crack squads of Luna Porcine Paratroopers.
Have you considered the energy involved?
Joseph
Henry Spencer
>Solar-powered or nuclear-powered directed-energy weapons based on the moon
>could lay waste enormous amounts of territory on the earth's surface within
>matters of minutes.
Solar-powered systems on the Moon, unless emplaced on an enormous scale,
are useless for half of each month because their site is in darkness.
There is no particularly good reason to base any of these things on the
Moon; any of them would be more effective in Earth orbit, where they are
so much closer to their targets. Diffraction and other forms of beam
spreading over Earth-Moon distances are very serious obstacles.
Besides, using directed-energy weapons to attack fixed targets is silly.
They're very inefficient; delivering the energy to the target via a bomb
works much better. The main application for directed-energy weapons is
hitting things that move too quickly for projectile weapons.
--
The problem is, every time something goes wrong, | Henry Spencer
the paperwork is found in order... -Walker on NASA | he...@zoo.toronto.edu
Henry Spencer
>|> Mr. or Mme. President, what do you do next?
>
After which you do the homework assignment: find the major flaw in the
basic concept of his weapon. Back to the drawing board, Mr/Mme President.
Pat
Hey I agree, it's totally a second strike weapons platform and it's
totally stabilizing. Now why isn't John Pike proposing this in lieu of
SDI?
pat
Matthew Gabriel
> Conclusion: the moon's too far away from the action to be an
>effective base. And _way_ too expensive.
But a very effective terror weapon. The V-2 was never the most
effective tactical force in Hitler's arsenal, but its very presence caused
fear, uncertainty, and doubt(FUD) in his opponents.
The same would be Nukes on the moon. As a tactical advantage, it
is a weak one. But as a psychological weapon, I can see how it would
cause a certain degree of panic in the populace and in the laymen in
power. Just enough FUD to cause the opposing power to at least take
pause.
Symbolism is everything.
SoupIsGood Food
Henry Spencer
>Due to the long flight time, any attempt to preemptively strike the
>Lunar base hasn't a prayer (if they're at all alert up there) -- they've
This assumes that they track all deep-space objects launched by the
opposition. That's easier said than done. An attack launched directly at
the Moon is going to be fairly obvious, sure... but if that new heavy Mars
probe is actually a multi-warhead attack system, things get harder.
Launch something that claims to be a large Mars probe. Its Mars-injection
burn is cut short, leaving it in a highly elliptical Earth orbit. It
maneuvers at apogee, perhaps repeatedly over several orbits, to reach a
trajectory that passes low over the lunar farside. There, it enters an
elliptical lunar orbit that passes very low over the base. The resulting
warning time is measured in seconds. With a bit of care, the whole system
can be tested over an unoccupied area of the Moon without anyone noticing.
Paul Dietz
>> You read Robert Heinlein, "The Moon is a Harsh Mistress", for starters.
> After which you do the homework assignment: find the major flaw in the
> basic concept of his weapon. Back to the drawing board, Mr/Mme President.
The mass driver is too easily located, for example by tracking
the projectiles. Also, its power supply is impossible to hide.
Once located, the thing is easily destroyed.
Paul
Burns Fisher
In article <DE4wH...@zoo.toronto.edu>, he...@zoo.toronto.edu (Henry Spencer)
writes:
|>In article <1995Aug25....@nb.rockwell.com> yqg...@sunshine.rockwell.com
( Jim Glass ; JF ; GLASS ; x586-0375 ; (W) ; 634-000) writes:
|>>|> Mr. or Mme. President, what do you do next?
|>>
|>
|>After which you do the homework assignment: find the major flaw in the
|>basic concept of his weapon. Back to the drawing board, Mr/Mme President.
Hmmm. Are you thinking about the rocks turning to gas before they hit the
ground when they enter the atmosphere at 7 miles/second? Or perhaps the
unpredictable atmospheric effects which would really reduce their accuracy
significanly without some sort of terminal control (I don't think Mike could do
anything once they entered the atmosphere).
Burns
Pat
Matthew Gabriel <sou...@enterprise.america.com> wrote:
>good...@mit.edu (Jason C Goodman) writes:
>
>> Conclusion: the moon's too far away from the action to be an
>>effective base. And _way_ too expensive.
>
> But a very effective terror weapon. The V-2 was never the most
>effective tactical force in Hitler's arsenal, but its very presence caused
>fear, uncertainty, and doubt(FUD) in his opponents.
Funny you mention the V-2. The V-2 provided no tactical effectiveness
and it's high cost diverted critical german resources away from
the ME-263 and Arato 192? which were their operational Jet fighters.
Had Von Brauns' rocket scientists been deployed to improving the
turbo machinery in the Jet engines instead of on rocket engines
and had they spent the funds on Peenemunde on making more jets
then it is quite possible Germany could have broken the air war
against them.
> The same would be Nukes on the moon. As a tactical advantage, it
>is a weak one. But as a psychological weapon, I can see how it would
>cause a certain degree of panic in the populace and in the laymen in
>power. Just enough FUD to cause the opposing power to at least take
>pause.
Yep, and just enough of a pause while the swiss bankers move into the
opposing country and seize all assets for defaulting on IMF obligations.
> Symbolism is everything.
Nope, Economics is everything. Give me enough money, I'll rule the world.
Bill Gates said that ;-)
Joshua B Hopkins
>In article <ssmith.51...@paltech.com> ssm...@paltech.com (Bob Ssmith) writes:
>>Solar-powered or nuclear-powered directed-energy weapons based on the moon
>>could lay waste enormous amounts of territory on the earth's surface within
>>matters of minutes.
>Solar-powered systems on the Moon, unless emplaced on an enormous scale,
>are useless for half of each month because their site is in darkness.
>There is no particularly good reason to base any of these things on the
>Moon; any of them would be more effective in Earth orbit, where they are
>so much closer to their targets. Diffraction and other forms of beam
>spreading over Earth-Moon distances are very serious obstacles.
There's another problem as well. If Ming the Merciless or Niven & Pournelle's
invading elephants tried this scheme they would be essentially impotent
50% of the time. A given target on Earth can't be seen or hit with lasers
for twelve straight hours out of every day.
That's an awfully big gap.
--
Josh Hopkins jbho...@uiuc.edu
"A study of more than 500,000 people in 151 cities found that those who live
in polluted cities increase their risk of dying by 15 to 17 percent."
- A recent "Health Update" in Better Homes and Gardens
steve hix
>
> In article <DE4wH...@zoo.toronto.edu> he...@zoo.toronto.edu wrote:
>
>
> > After which you do the homework assignment: find the major flaw in the
> > basic concept of his weapon. Back to the drawing board, Mr/Mme President.
>
> the projectiles.
How much would early course corrections help in making detection of the
launcher harder?
> Also, its power supply is impossible to hide.
Bury it deeper?
Stuff it (or them) on the back side, and beam power around to the laucher?
> Once located, the thing is easily destroyed.
Anti-missile defenses for the launcher might be easier than an earth-based
defense from the lunies, too.
On the other hand, putting in an anti-missile defense on a commercial cargo
launching system, like the one Mike used, might look just a bit suspicious...
Bob Ssmith
>In article <ssmith.51...@paltech.com> ssm...@paltech.com (Bob Ssmith) writes:
>>Solar-powered or nuclear-powered directed-energy weapons based on the moon
>>could lay waste enormous amounts of territory on the earth's surface within
>>matters of minutes.
>Solar-powered systems on the Moon, unless emplaced on an enormous scale,
>are useless for half of each month because their site is in darkness.
Not if the base was located at one of the LUNAR POLES. The
solar-energy collectors would have to be set up vertically, and
they'd have to track the sun, but they would also have continuous
access to sunlight. (A lunar-polar base would have the
advantages also of not being in clear view from the earth, and
deep-space viewing, without interfering 'earthshine,' would be
possible from just over the polar horizon, away from the earth.)
>Diffraction and other forms of beam
>spreading over Earth-Moon distances are very serious obstacles.
>Besides, using directed-energy weapons to attack fixed targets is silly.
>They're very inefficient; delivering the energy to the target via a bomb
>works much better. The main application for directed-energy weapons is
>hitting things that move too quickly for projectile weapons.
If the directed-energy weapon were a large MASER, which is a microwave
wavelength LASER, a tight beam could be held on a relatively small
(mile-wide-or-so) target on the earth. Also, you don't need to deliver a lot
of microwave energy to kill people -- only enough to elevate the temperature
of living tissue by a few degrees C.
Bob Ssmith
"Seen it, done it, wore the T-shirt, believed it, deleted it."
Frank Scrooby
with which to build this proposed base on the moon AND ship the nukes out there
wouldn't it just be whole lot easier to ship a suitcased sized nukes into the
target country's (the US) major cities and hit their military bases with
stealthed cruise missiles.
The other questions is what stupid cretin would be foolish enough to play the
nuclear standoff game with America ? The United States have one of the top two
arsenals in the world. Even your first strike incinirates all of North America
the retalitory strike from just the United States Navy's nuclear submarine would
enough to certify extinction for every last living thing on the globe.
The problem with space based particle beam weapons is the atmosphere. Won't the
atmosphere's particles (and all the pollution we've put up there in the last two
centuries) scatter a laser or particle into nothing? I remember that being a
problem meantioned in the Reagan area when SDI was still making news and costing
tax payers money.
D L Jones
>
>In article <DE4wH...@zoo.toronto.edu> he...@zoo.toronto.edu wrote:
>
>>> You read Robert Heinlein, "The Moon is a Harsh Mistress", for starters.
>
>> After which you do the homework assignment: find the major flaw in the
>> basic concept of his weapon. Back to the drawing board, Mr/Mme President.
>
>
>The mass driver is too easily located, for example by tracking
>Once located, the thing is easily destroyed.
>
No, most of these plot points were dealt with in the book. A second,
underground catapult was built to backup the one that the dastardly
Earthlings would inevitably destroy.
I think Henry wants us to point out that, as has often been mentioned
around here, a ground launched projectile launched at less than escape
velocity will execute part of an elliptical orbit and smash into the
surface somewhere else. Some onboard rockets are needed to kick the
projectile into a non-crashing orbit.
In fact, RAH gave his grain barges and rocks just such capabilities,
though you can argue he couldn't have given them enough to do the job and
deliver the right kind of payload. I'm no expert.
Other objections: note that Apollo return burns occurred over Farside,
and the catapults are on Nearside. RAH writes of a "hump" that is 11
km/s high from the Earth side and only 3 km/s high from the Lunar side -
a vast oversimplification of orbital mechanics involved. The projectiles
may not have been big enough to get thru the atmosphere and do the damage
described (kilotons of TNT equiv.). And so on...
Marmiteman.
Bob Ssmith
>In article <ssmith.51...@paltech.com> ssm...@paltech.com (Bob Ssmith) writes:
>>Solar-powered or nuclear-powered directed-energy weapons based on the moon
>>could lay waste enormous amounts of territory on the earth's surface within
>>matters of minutes.
>Have you considered the energy involved?
Yes. Consider that the beamed power from a large MASER on the moon need
deliver only enough energy to raise the temperature of living tissue by a few
degrees C to be lethal. (It would have some of the properties of that
'capitalist weapon,' the neutron bomb -- it would destroy people, but not
property.)
Bob Ssmith
Joshua B Hopkins
>In article <41vc3p$7...@ptdcs5.al.intel.com> gre...@ptdcs2.intel.com (Jeff Greason) writes:
>>Due to the long flight time, any attempt to preemptively strike the
>>Lunar base hasn't a prayer (if they're at all alert up there) -- they've
>>got days to see it coming and for the groundside power to react...
>This assumes that they track all deep-space objects launched by the
>opposition. That's easier said than done. An attack launched directly at
>the Moon is going to be fairly obvious, sure... but if that new heavy Mars
>probe is actually a multi-warhead attack system, things get harder.
[Henry describes a good way to sneak weapons past lunar defenses using
deceptive orbits. Henry, if I ever take over the Moon, I want you on
my side.]
This makes me wonder how much effort it would really take to land nukes
on a lunar target. Such sneakiness may not be necessary. Consider:
Since the impulsive burn to send a payload from Earth to the Moon
on a standard elliptical trajectory can be done "behind" the Earth
as seen from the Moon, IR systems couldn't be used the way we detect missile
launches now. Detecting a warhead-sized target near Earth from a radar
site on the Moon would require a very large antenna. Moreover, the geometry
to the lunar radar would be known to within a few degrees throughout most
of the trajectory, even if the precise location was unknown (assuming that
the radar was somewhere *on* the Moon, not in a high orbit). My understanding
is that radar stealthing is really pretty easy if you only have to control
radar reflection in one direction. Therefore, it would seem to me that
a stealthed warhead could acheive surprise on the order of what ICBM's do
now (i.e. on the order of a half hour or so) simply be being reasonably
careful. One might not need to devise complex orbits or require
significant delta-v capability on the warhead.
Thomas J. Nugent, Jr.
he...@zoo.toronto.edu (Henry Spencer) wrote:
>In article <41vc3p$7...@ptdcs5.al.intel.com> gre...@ptdcs2.intel.com (Jeff
>Greason) writes:
[people on the moon could see an attack coming for hours/days]
>This assumes that they track all deep-space objects launched by the
>opposition. That's easier said than done.
OK, I'm pretty much ignorant about this, so I'll ask: _how_ difficult
is it? The US Space Command uses _how_ many radar sites, which are
_how_ sophisticated/require _how_ much power, to track everything they
do (all objects greater than 1 cm in length, right?)?? Also, how
much do they rely on computers for identification/tracking? I imagine
their resolution (the above mentioned 1 cm) depends on distance - most
of what they track is LEO, right? How "far" can they see with any
decent resolution?
>Launch something that claims to be a large Mars probe. Its Mars-injection
>burn is cut short, leaving it in a highly elliptical Earth orbit. It
>maneuvers at apogee, perhaps repeatedly over several orbits, to reach a
>trajectory that passes low over the lunar farside. There, it enters an
>elliptical lunar orbit that passes very low over the base. The resulting
>warning time is measured in seconds. With a bit of care, the whole system
>can be tested over an unoccupied area of the Moon without anyone noticing.
Assuming we're not going to have such a lunar base up for at least a few
years, and that the people there will thus have access to even more
advanced computers than today; then if they have a radar site or two
near their base, which uses artificial intelligence to identify
and keep track of all objects it sees with the radar (which should
be doable even today), and if they also keep track of announced
launches and destinations, they should be fine. (ie., if it's
supposed to be going to Mars, but it goes to elliptic Earth orbit,
then moon orbit, they're most likely going to be able to see it,
unless it is constantly hidden by Earth or the Moon.)
Am I mistaken somewhere here?
-- Tom N.
Tom Nugent: Interning through U. Pittsburgh JSTM program at Ishikawajima-
Harima Heavy Industries, Yokohama Research Institute, Japan. But just
because I'm associated with them doesn't mean I speak for them.
email: nug...@gol.com URL: http://www2.gol.com/users/nugent
Join the JapanSpace mailing list by sending me email w/ your email address
Paul Dietz
> If the directed-energy weapon were a large MASER, which is a microwave
> wavelength LASER, a tight beam could be held on a relatively small
> (mile-wide-or-so) target on the earth. Also, you don't need to deliver a lot
> of microwave energy to kill people -- only enough to elevate the temperature
> of living tissue by a few degrees C.
This is a lot of energy. To heat 50 kilograms of water by 5 C
requires about a megajoule of energy: about the yield of a stick of
dynamite.
It would also have to be delivered quickly, or the victims would
take cover. So we're talking about very high power levels, with
beams of 100 GW or more.
Paul
Paul Dietz
>> The mass driver is too easily located, for example by tracking
>> the projectiles.
>
>How much would early course corrections help in making detection of the
>launcher harder?
Not much: radar or IR sensors could detect the projectiles soon
after launch.
Also, seismic sensors on the moon could easily detect the
waves induced by the recoil of the launcher.
>> Also, its power supply is impossible to hide.
>
>Bury it deeper?
Sorry, it has to dissipate waste heat somehow. It could be
hidden for a finite time by using a large heat sink.
>Stuff it (or them) on the back side, and beam power around to the laucher?
Now you've introduced more weak links into the chain.
>> Once located, the thing is easily destroyed.
>
>Anti-missile defenses for the launcher might be easier than an earth-based
>defense from the lunies, too.
Any point defense could be overwhelmed. Nearby detonations swamp the
sensors, for example. And the attackers could just drop big rocks.
Which one is the gigaton warhead?
Paul
Joseph Askew
>>Have you considered the energy involved?
>Yes. Consider that the beamed power from a large MASER on the moon need
>deliver only enough energy to raise the temperature of living tissue by a few
>degrees C to be lethal. (It would have some of the properties of that
>'capitalist weapon,' the neutron bomb -- it would destroy people, but not
>property.)
Consider how long it would take people to go about carrying
aluminium umbrellas. Large areas are out.
Joseph
Bruce Lewis
It's true that any attack against the moon could do a TLI burn
on the Earth's farside relative to "Luna City" or whatever, but
I think it's safe to say that the Loonies are going to have SOME
kind of DEW before they get involved in hostilties with
Big Blue (Marble). How about their own fleet of Keyholes in
GEO? Or a BIG, BIG (really big!) solar-powered phased-array
radar at L5...no, make that a tuneable maser. After all, sunlight
is free... Or lots of little radar sites across the Nearside instead of
one big one? Or...
You get the point. From what I've read here, there seems to be no
reason (other than technical, big deal) why the brave boys at
Moonbase 999 couldn't hold off an attack from the Terran Empire
or whatever. I would remind you of the words of U.S. Library of
Congress Senior Analyst John Collins in MILITARY SPACE FORCES:
THe NEXT 50 YEARS (as quoted by Alvin and Heidi Toffler in
WAR AND ANTI-WAR, 1993): "Who rules circumterrestrial space
commands Planet Earth. Who rules the moon commands circum-
terrestrial space. Who rules L4 and L5 commands the Earth-Moon
system." Pretty plain!
So let's get to work building that fleet of Orion-style space cruisers.
I want that mass-driver up and running by 2010, people! Paging
Bob Heinlein...
Bruce
Joshua B Hopkins
>In article <DE4wB...@zoo.toronto.edu> he...@zoo.toronto.edu (Henry Spencer) writes:
>>In article <ssmith.51...@paltech.com> ssm...@paltech.com (Bob Ssmith) writes:
>>>Solar-powered or nuclear-powered directed-energy weapons based on the moon
>>>could lay waste enormous amounts of territory on the earth's surface within
>>>matters of minutes.
>>Diffraction and other forms of beam
>>spreading over Earth-Moon distances are very serious obstacles.
>If the directed-energy weapon were a large MASER, which is a microwave
>wavelength LASER, a tight beam could be held on a relatively small
>(mile-wide-or-so) target on the earth. Also, you don't need to deliver a lot
>of microwave energy to kill people -- only enough to elevate the temperature
>of living tissue by a few degrees C.
[Pardon me while I play with the calculator again]
Making some reasonable assumptions about the apparent area of a human
being, it looks to me like you need to dump on the order of 100 Gigajoules
into a square mile to kill a human being. I suppose if you're willing
to take about a minute for this to work, you need a power supply on the
order of a few gigawatts. The power supply for that energy level and the
transmitter for that level of precision are really, really, really, big.
Moreover, this doesn't sound like a really scary weapon. It can't hit
a given target 50-75% of the time. When it *can* hit a target, death takes
a long time, and counter measures are very straightforward. For example,
could a weapon of this type actually hurt someone inside a good sized
building?
Bryan MacBurney
>
>In article <1995Aug25....@nb.rockwell.com>
yqg...@sunshine.rockwell.com (
> Jim Glass ; JF ; GLASS ; x586-0375 ; (W) ; 634-000) writes:
>>|> Mr. or Mme. President, what do you do next?
>>
>
>After which you do the homework assignment: find the major flaw in the
>basic concept of his weapon. Back to the drawing board, Mr/Mme
President.
And for those of us who remain completely at a loss, will you be revealing
the flaw that you had in mind? I'm rather curious, but hardly competent
to weigh the replies so far.
Thank you kindly,
Bryan
--
bryan_m...@mindlink.bc.ca
Burns Fisher
In article <42739c$j...@dlsn31.dal.mobil.com>, D L Jones <marmi...@aol.com>
writes:
|>>
|>>> After which you do the homework assignment: find the major flaw in the
|>>> basic concept of his weapon. Back to the drawing board, Mr/Mme President.
|>>
|>>
|>
|>around here, a ground launched projectile launched at less than escape
|>velocity will execute part of an elliptical orbit and smash into the
|>surface somewhere else. Some onboard rockets are needed to kick the
|>projectile into a non-crashing orbit.
|>
True, but to go from moon to earth, you DO exceed the moon's escape velocity.
You could not go into lunar orbit with a catapult without some capability to
accelerate on the opposite from the cat, but you could certainly get up past L1
(is that the right one?) so you fall to earth without any major orbit change.
|>In fact, RAH gave his grain barges and rocks just such capabilities,
|>though you can argue he couldn't have given them enough to do the job and
|>deliver the right kind of payload. I'm no expert.
His on-board rockets were used for fine aiming on the way, and possibly (don't
remember) to slow down the grain barges as they splash-down.
Burns
me...@cars3.uchicago.edu
The power estimates sound about right and, from diffraction limit
considerations the size of the broadcasting antena should be not much
smaller than the size of the area being hit, of the order of a square
kilometer or so. Also, as mentioned above, shielding should be
relatively straightforward. Anyway, anybody with the technology and
the resources to put an installation of this size on the moon, and the
willingness to use these resources for military purposes, can do way
better with earth based weaponry.
Mati Meron | "When you argue with a fool,
me...@cars3.uchicago.edu | chances are he is doing just the same"
Henry Spencer
>>>You read Robert Heinlein, "The Moon is a Harsh Mistress", for starters.
>>After which you do the homework assignment: find the major flaw in the
>
>And for those of us who remain completely at a loss, will you be revealing
I suppose I should...
The basic problem with the lunar-catapult weapon is that people think it's
magic, and it's not. It isn't a case of tossing a baseball into the lunar
sky and seeing a KABOOM on Earth a couple of days later. Sure, the rock
picks up quite a bit of speed falling into Earth's gravity well. However,
for that to happen, you must first get it off the Moon and into a
trajectory that intersects the Earth. The delta-V required for that is
*not* trivial. My back-of-the-envelope calculation a while ago said that
you have to supply an amount of energy equal to 5-10% of the final impact
energy. So to get nuclear-weapon-sized impacts, you need a huge catapult
driven by an enormous power plant. Heinlein rather glosses over this,
especially the power plant, but in fact it would be a massive project.
It would work (although you'd have to change some of the details from
what Heinlein presented*), but the same effort devoted to more mundane
weaponry would work better.
* In particular, linear induction motors don't scale up well to large
sizes and high accelerations. To build a large catapult you'd almost
certainly have to use a linear synchronous motor -- with coils on the
projectile -- instead.
John Woods
>>>Solar-powered or nuclear-powered directed-energy weapons based on the moon
>>>could lay waste enormous amounts of territory on the earth's surface within
>>>matters of minutes.
>Yes. Consider that the beamed power from a large MASER on the moon need
>degrees C to be lethal.
Amplified for the thinking impaired:
HAVE YOU CONSIDERED THE ENERGY INVOLVED?
Sunlight is in the ballpark of one kilowatt per square meter. (Crosscheck:
my microwave oven delivers under .7 kilowatt to around a quarter of a square
meter, and takes several seconds to raise a small glass of water a few degrees
C. So we are in the right ballpark, within a factor of ten, certainly.) We
want to deliver at least 1 kilowatt per square meter.
Let's threaten a smallish city, 10km on a side. 100 million square meters.
That's 100 gigawatts to be delivered to the target area, *after* beam spreading
and atmospheric losses. 100+ gigawatts is one AWFUL big powerplant, of which
one simple 1MT nuke would make an AWFUL big mess. That's also one AWFUL big
antenna, to keep the beam spreading DOWN to a mere 10km on a side, and would
represent a KICK ME sign that could easily be seen from the Earth, and you
can be just about certain that someone would take that advice.
Henry Spencer
>>spreading over Earth-Moon distances are very serious obstacles.
>
>If the directed-energy weapon were a large MASER, which is a microwave
>wavelength LASER, a tight beam could be held on a relatively small
>(mile-wide-or-so) target on the earth. Also, you don't need to deliver a lot
>of living tissue by a few degrees C.
Masers are *worse*, not *better*, for beam spreading -- shorter
wavelengths are easier to beam. Holding a 1.5km spot with (say) 1cm
microwaves at lunar distance (call it 400,000km) requires a maser roughly
2.5km wide. (Actually, there is no great advantage here in using a maser
rather than a more ordinary microwave source.)
Sure, you can kill a human by elevating his body temperature only a few
degrees -- but you have to do that quickly enough to overwhelm his body's
cooling system, which will be trying very hard to keep his temperature
stable. You also have to do it quickly enough to prevent him from taking
shelter under microwave-opaque surfaces, which will be difficult unless
you build your giant beam weapon in total secrecy, since simple aluminum
foil is quite effective shielding against microwaves.
As for the energy needed... as a rough guess, say we need ten times the
power density of sunlight to have the desired effect at the necessary
speed (I would expect to need more). Sunlight is very roughly 1kW/m^2,
so for a 1.5km area we need about 18GW of microwave power. Conversion
from electricity to microwaves is fairly efficient, but conversion from
sunlight to electricity is not. Call the overall efficiency 10%, and
we need a lunar-surface solar array 15km across. More, actually, since
the sun won't be hitting it vertically most of the time.
Engineering works on this scale will be impossible to hide or move, and
one or two small nuclear missiles would destroy them completely.
Bob Ssmith
Hmm. Good point.
Bob Ss.
Daniel Pawtowski
D L Jones <marmi...@aol.com> wrote:
>
>No, most of these plot points were dealt with in the book. A second,
>underground catapult was built to backup the one that the dastardly
>Earthlings would inevitably destroy.
What others on this thread have been saying is that the energies necessary
to hurl projectiles large enough and fast enough to cause nuke-level
destruction on Earth are simply too large. The catapault and power source
would simply be too big to hide underground. I suppose you could bury them
afterwards, but the construction site would be visible from Earth with
binoculars while you were putting it in. This is a HUGE catapault we're
talking about, there.
I suppose you could hypothesize a smaller launcher, and just say Mike
was really tossing 50 projectiles where RAH said he was throwing one.
Any rock of significant size is gonna cause damage if dropped from
orbit, so enough rocks will flatten a city. A cloud of hundreds of small
rocks would be even harder to "shoot down" than a single large one. Of
course, it'll also take far longer to launch that many, and gives the
Earthlings a better chance to track down your launcher.
Daniel Pawtowski
dpaw...@vt.edu
Daniel Pawtowski
Joshua B Hopkins <jbho...@ux5.cso.uiuc.edu> wrote:
>he...@zoo.toronto.edu (Henry Spencer) writes:
>
>
>Since the impulsive burn to send a payload from Earth to the Moon
>on a standard elliptical trajectory can be done "behind" the Earth
>as seen from the Moon, IR systems couldn't be used the way we detect missile
>launches now. Detecting a warhead-sized target near Earth from a radar
>site on the Moon would require a very large antenna. Moreover, the geometry
Bad assumption here: Any Earth-based nation with the resources to put
a missile base on the moon will also have radar and other sensors on
Earth (both on it's own soil and with allies), and is highly likely to
have a good satellite network. You'd have to launch through all that in
addition to getting base moon-based radars. Not to mention other "National
Intellegence Resources" that will be busy trying to find out if there's a
warhead in your "Heavy Mars Probe".
If the nation in question isn't Earth-based, then we run across an
entirely different set of questions by worrying about alien technology.
Daniel Pawtowski
dpaw...@vt.edu
Jmkistler
earth using moon-based missiles. Thus far all responses have discussed
the pros and cons of moon-to-earth launches of missiles as a threat to
earth.
How about a different type of threat using moon-based missiles?
Rather than launching them at the earth, launch them or detonate them on
the moon itself. Depending on the craziness of your antagonists and the
power of the weapons, more of a credible threat might be obtained by using
nuclear explosions to damage the normal orbit of the moon around the
earth. You could go two routes, as I see it. Either centralize enough
powerful explosions on the dark side of the moon to nudge it into a closer
orbit, thus causing tremendous climactic changes and tidal problems (so
long as the evil-doers don't mind living on the moon permanently). Or use
more carefully-shaped charges to blow chunks out of the lunar surface to
cause damaging meteoric showers.
It seems to me that since the moon is smaller than earth and yet a
vital part of earth's ecosystem, the greater threat from lunar weapons is
actually lunar destruction of various sorts.
Just some thoughts. Perhaps demented thoughts, but thoughts none the
less.
Thomas J. Nugent, Jr.
jbho...@ux4.cso.uiuc.edu (Joshua B Hopkins) wrote:
>Making some reasonable assumptions about the apparent area of a human
>being, it looks to me like you need to dump on the order of 100 Gigajoules
>into a square mile to kill a human being. I suppose if you're willing
>to take about a minute for this to work, you need a power supply on the
>order of a few gigawatts. The power supply for that energy level and the
>transmitter for that level of precision are really, really, really, big.
>Moreover, this doesn't sound like a really scary weapon.
[remaining arguments of how un-effective this would be, deleted]
What about a crazy on the moon who didn't want to threaten any
single country, but just wanted to harm the Earth as much as possible
(I said he/she's a crazy, choose whatever reason you want). What about
beaming infrared energy to the poles in order to melt those ice-caps?
To raise the water level by one meter worldwide, my very rough
calculation says one would need to melt a cube of ice 80 km on a
side. Being overly optimistic, if we only need to raise the
temperature of the ice 1 degree C to melt it, this requires roughly
5*10^20 Joules. For comparison, a 1 km x 1 km solar array on
the moon could optimistically speaking expect to collect 1*10^13
Joules in one day. Oh well, so much for that idea.
I vaguely remember hearing that the ice doesn't have to be melted
to cause a catastrophe. Instead, as chunks of ice break off the edge
of glaciers and fall into the ocean, they displace a serious volume.
This, and not huge volumes of ice melting, is what actually would
be the danger, or so I've heard. I wonder how much one could "break up"
chunks of ice, if one can only focus on, say, a 1km wide area? If
one "perforated" a glacier, how much faster could one expect the
ocean-side ice to move towards the ocean?
John Childers
>>>Diffraction and other forms of beam
>>>spreading over Earth-Moon distances are very serious obstacles.
>>
>>If the directed-energy weapon were a large MASER, which is a microwave
>>wavelength LASER, a tight beam could be held on a relatively small
>>(mile-wide-or-so) target on the earth. Also, you don't need to deliver a lot
>>of living tissue by a few degrees C.
[...]
>As for the energy needed... as a rough guess, say we need ten times the
>power density of sunlight to have the desired effect at the necessary
>speed (I would expect to need more). Sunlight is very roughly 1kW/m^2,
>so for a 1.5km area we need about 18GW of microwave power. Conversion
>from electricity to microwaves is fairly efficient, but conversion from
>sunlight to electricity is not. Call the overall efficiency 10%, and
>we need a lunar-surface solar array 15km across. More, actually, since
>the sun won't be hitting it vertically most of the time.
>Engineering works on this scale will be impossible to hide or move, and
>one or two small nuclear missiles would destroy them completely.
Efficiency would be greatly improved by covering the same area with
steerable solar reflectors. They don't have to be nearly as large as the
microwave transmitters but they will need a long focal lenght. Then you
can toast a city with, humm (15)^2/(1.5)^2, 100 times normal sunlight.
Of coures you can only do this for about 1 week out ever 4 due to alignment
problems and it's still a big easy target.
---
John Childers | ===+========:+:
UNC Charlotte | _/ \_ |
Internet? Try | |\ /| -);
jech...@uncc.edu | | X |
--------------------------| __________|/_\|___ .^.
Disclaimer? Does anyone | |Caution Spacecraft| /|=|\
on the net ever officially| |Under Construction| |_____|
speak for their computer? | |/\/\/\/\/\/\/\/\/\| / ^ ^ \
--------------------------------------------------------------
Bob Ssmith
>In article <42glnr$l...@vixen.cso.uiuc.edu>, jbho...@ux4.cso.uiuc.edu (Joshua B Hopkins) writes:
>>ssm...@paltech.com (Bob Ssmith) writes:
>>
>>>In article <DE4wB...@zoo.toronto.edu> he...@zoo.toronto.edu (Henry Spencer) writes:
>>
>>>>In article <ssmith.51...@paltech.com> ssm...@paltech.com (Bob Ssmith) writes:
>>>>>Solar-powered or nuclear-powered directed-energy weapons based on the moon
>>>>>could lay waste enormous amounts of territory on the earth's surface within
>>>>>matters of minutes.
>>
>>>>Diffraction and other forms of beam
>>>>spreading over Earth-Moon distances are very serious obstacles.
>>
>>>If the directed-energy weapon were a large MASER, which is a microwave
>>>wavelength LASER, a tight beam could be held on a relatively small
>>>(mile-wide-or-so) target on the earth. Also, you don't need to deliver a lot
>>>of microwave energy to kill people -- only enough to elevate the temperature
>>>of living tissue by a few degrees C.
>>
>>[Pardon me while I play with the calculator again]
>>
>>Making some reasonable assumptions about the apparent area of a human
>>being, it looks to me like you need to dump on the order of 100 Gigajoules
>>into a square mile to kill a human being. I suppose if you're willing
>>to take about a minute for this to work, you need a power supply on the
>>order of a few gigawatts. The power supply for that energy level and the
>>transmitter for that level of precision are really, really, really, big.
>>Moreover, this doesn't sound like a really scary weapon. It can't hit
>>a given target 50-75% of the time. When it *can* hit a target, death takes
>>a long time, and counter measures are very straightforward. For example,
>>could a weapon of this type actually hurt someone inside a good sized
>>building?
>The power estimates sound about right and, from diffraction limit
>considerations the size of the broadcasting antena should be not much
>smaller than the size of the area being hit, of the order of a square
>kilometer or so. Also, as mentioned above, shielding should be
>relatively straightforward. Anyway, anybody with the technology and
>the resources to put an installation of this size on the moon, and the
>willingness to use these resources for military purposes, can do way
>better with earth based weaponry.
Alright, I did the calculations. Forget the MASER.
Bob Ss.
Bob Ssmith
>In article <ssmith.54...@paltech.com> ssm...@paltech.com wrote:
>> If the directed-energy weapon were a large MASER, which is a microwave
>> wavelength LASER, a tight beam could be held on a relatively small
>> (mile-wide-or-so) target on the earth. Also, you don't need to deliver a lot
>> of microwave energy to kill people -- only enough to elevate the temperature
>> of living tissue by a few degrees C.
>This is a lot of energy. To heat 50 kilograms of water by 5 C
>requires about a megajoule of energy: about the yield of a stick of
>dynamite.
>It would also have to be delivered quickly, or the victims would
>take cover. So we're talking about very high power levels, with
>beams of 100 GW or more.
I agree, Paul. I hereby retract my MASER assertion.
Bob Ssmith
Bob Ssmith
>In article <ssmith.53...@paltech.com> ssm...@paltech.com (Bob Ssmith) writes:
>>Consider that the beamed power from a large MASER on the moon need
>>deliver only enough energy to raise the temperature of living tissue by a few
>>degrees C to be lethal. (It would have some of the properties of that
>>'capitalist weapon,' the neutron bomb -- it would destroy people, but not
>>property.)
>Consider how long it would take people to go about carrying
>aluminium umbrellas. Large areas are out.
Okay, how 'bout massive amounts of rocks being launched from the moon toward
cities on earth. What about defending against that kind of ultra lo-tech
assault?
Bob Ss.
Joshua B Hopkins
>The basic idea for this novel, as I recall, was to create a threat to the
>earth using moon-based missiles. Thus far all responses have discussed
>the pros and cons of moon-to-earth launches of missiles as a threat to
>earth.
>How about a different type of threat using moon-based missiles?
>Rather than launching them at the earth, launch them or detonate them on
>the moon itself. Depending on the craziness of your antagonists and the
>power of the weapons, more of a credible threat might be obtained by using
>nuclear explosions to damage the normal orbit of the moon around the
>earth.
The amount of energy required to do this is utterly and completely beyond
the capability of human beings to control in the forseeable future.
Trying to defend Earth from terrorists who could move the Moon is only
slightly less crazy than trying to defend against God.
Joshua B Hopkins
>Re: lunar DEW vs. attack from Earth:
>It's true that any attack against the moon could do a TLI burn
>on the Earth's farside relative to "Luna City" or whatever, but
>I think it's safe to say that the Loonies are going to have SOME
>kind of DEW before they get involved in hostilties with
>Big Blue (Marble). How about their own fleet of Keyholes in
>GEO? Or a BIG, BIG (really big!) solar-powered phased-array
>radar at L5..
Okay, so the first move in the opening of hostilites is to shoot down
the spy satellites and fire a few tons of ball bearings towards L5.
Neither of those positions are defensible. Suddenly the lunar bad
guys are back where they started.
Whether you choose to put the radar site at L5 or multiple sites
scattered on the Moon doesn't affect my original point. If the location
of the radar site(s) is restricted to an area of a few degrees, it
is very easy to simply reflect the radar energy away from them. The
difficulty in making aircraft stealthy is that the radar can be anywhere.
>You get the point. From what I've read here, there seems to be no
>reason (other than technical, big deal) why the brave boys at
>Moonbase 999 couldn't hold off an attack from the Terran Empire
>or whatever.
Yeah, well, if you leave out the engineering difficulties, pretty much
anything becomes easy.
Henry Spencer
is only 3.5x10^28 J (stupid calculator has counterintuitive precedence
rules). This doesn't invalidate my argument, however.
D L Jones
>
>In article <42739c$j...@dlsn31.dal.mobil.com>, D L Jones <marmi...@aol.com>
>|>>
>
>|>In fact, RAH gave his grain barges and rocks just such capabilities,
>|>though you can argue he couldn't have given them enough to do the job and
>|>deliver the right kind of payload. I'm no expert.
>
>His on-board rockets were used for fine aiming on the way, and possibly (don't
>remember) to slow down the grain barges as they splash-down.
>
>Burns
As I pointed out in another conversation, the "maneuvering rockets" were
able to jolt poor Manny in a way his Loonie body was not used to on the
way to Earth, which means some pretty substantial thrust there,
considering the barges must have massed hundreds or thousands of tonnes.
A minor point in the novel, perhaps, but a discrepancy nonetheless.
I really would like to have a look at the requirements for Lunar
catapults. If anyone can point me at software that's reasonably easy to
use (3-D calculations preferred) I'd be grateful. As an ex-chemist in
software production I have enough background to give me a start. My
intuition still says that the most efficient catapults will be located on
Farside.
Henry Spencer
>...more of a credible threat might be obtained by using
>nuclear explosions to damage the normal orbit of the moon around the
Uh, you need to do some numbers on this one. The orbital kinetic energy
of the Moon is about 2x10^48 J; significantly altering its orbit requires
significantly altering that. The energy release of a 20 MT bomb is about
1x10^17 J. There is, shall we say, some disparity here between the means
you are using and the effects you are hoping for. Won't work.
> It seems to me that since the moon is smaller than earth and yet a
>vital part of earth's ecosystem, the greater threat from lunar weapons is
>actually lunar destruction of various sorts.
The only aspects of the Moon that have major effects on Earth's ecosystem
are its mass and orbit, which are essentially impossible to change using
near-future technology. Rearranging a few rocks on the Moon's surface
won't have any effect on Earth.
Joshua B Hopkins
>In article <427oar$g...@vixen.cso.uiuc.edu>,
> Bad assumption here: Any Earth-based nation with the resources to put
>a missile base on the moon will also have radar and other sensors on
>Earth (both on it's own soil and with allies), and is highly likely to
>have a good satellite network.
Sure, but any earthbound nation which wants to wage war on any other
earthbound nation isn't going to waste its time futzing around with
doomsday weapons on the Moon. Standard submarine launched nuclear missiles
are far more effective, orders of magnitude cheaper, and work with available
technology.
> If the nation in question isn't Earth-based, then we run across an
>entirely different set of questions by worrying about alien technology.
If, by "alien" you mean Kligon and Vorlon type aliens, sure. In which case
the argument would be totally pointless and I wouldn't be involved in it.
However, non-terrestrial is not synonymous with non-human. Human
societies based on the Moon, Mars or in free space are not that far fetched.
I would agree that if you mean "unpredictable future technology" when you
say "alien" that you have a point. However, the solar insolation constant
or the beam diffraction problem aren't going to change radically in the
next few decades.
Basically, this discussion has to be predicated on the assumption that
we are talking about a human "nation" or society based on the Moon sometime
in the forseable future (say, 100 years). If we agree to those common
assumptions, then this can be a reasonable discussion. Otherwise it's
simply make believe.
Henry Spencer
>I think it's safe to say that the Loonies are going to have SOME
>kind of DEW before they get involved in hostilties with
True, but searching very large volumes of space for uncooperative targets
is inordinately difficult.
Radar is essentially useless for deep-space work, since (for the relevant
case) the power of the return signal is inversely proportional to the
*fourth power* of distance (the inverse-square law gets you twice, once on
the outbound beam and once on the return signal). You can't change this
with masers etc, by the way, because diffraction still spreads the beam.
Lidar involves less beam spreading (due to the shorter wavelengths), but
the downside of that is that you can't search a football field using a
magnifying glass -- the narrow beam is useless unless you already have
a fairly good idea of where to point it.
Passive detection systems (IR and the like) aren't so bad -- at least
they're only inverse-square -- but they have very faint signals to begin
with, and you have to worry about background noise, which is substantial.
Note that Heinlein got this one right: when Earth forces attempt to
invade the rebelling lunar colony, the attack comes as a complete surprise,
with only seconds of warning from short-range sensors.
Jmkistler
Moon. I am an author and not a scientist, and it was a crazy idea.
However, I am willing to fight a little harder on the idea of blasting
parts of the moon with nuclear weapons and directing those blasts of rock
toward the Earth. While all of you are correct that it is still wasting
an awful lot of energy and we might as well just fire the missiles at
earth.... one advantage to the multiple projectile theory (whether moon
rocks or missiles) is that the earth probably could not defend against it.
But whereas it would cost a fortune to create hundreds or thousands of
reentry vehicles to barrage the earth at one time, a minimal number of
missiles could be used to create a meteoric hailstorm from lunar material.
My plan would be to use one large nuke to blast a huge amount of lunar
material from the surface, and use smaller airblasts (nuke or
conventional) all around to direct the rocks toward earth. If it worked,
about five nuclear devices could send thousands of large projectiles at
the earth. The cost to benefit ratio of inflicting such a damaging attack
using only five devices while overwhelming the enemies defenses seems to
me to be quite high. While the earth would have two to three days of
observing the trajectory of the incoming objects, they would have little
chance of stopping them except by using high orbit or extra-orbital
detonations to hopefully deflect or lessen the size of the approaching
debris.
But still, I am no scientist. How would you go about deflecting or
defusing such a situation?
Mark Adler
>> Rearranging a few rocks on the Moon's surface
>> won't have any effect on Earth.
Henry was referring to ecological effects, but I can't resist mentioning
a cartoon I saw many years ago in a Playboy. It was two guys on a
balcony with martini's looking up at the moon, on which was clearly
visible a hugh Playboy bunny head (tm) taking up a good bit of the area
of the near side. The comment by the fellows was something like: "it
cost him a bundle, but it was worth it."
mark
Henry Spencer
> Bad assumption here: Any Earth-based nation with the resources to put
>a missile base on the moon will also have radar and other sensors on
>Earth (both on it's own soil and with allies), and is highly likely to
Uh, so? Radar is essentially useless beyond LEO. Satellite networks do
okay at picking up rocket burns, but do rather poorly at tracking inert
objects. Sure, they'll pick up the "heavy Mars probe" as it boosts out of
LEO... but you need precision tracking to tell the difference between an
escape trajectory and a very-high-apogee elliptical orbit at that point;
the far-from-Earth final velocity is very sensitive to small changes in
near-Earth end-of-burn velocity. They'll know it departed, but if you
take some simple precautions, they won't know where it's headed.
>... Not to mention other "National
>Intellegence Resources" that will be busy trying to find out if there's a
>warhead in your "Heavy Mars Probe".
The same "National Intelligence Resources" that estimated the USSR would
have 150-200 ICBMs operational by mid-1961? (The actual number,
determined after the first US spy satellites became operational, was 6.)
Keeping a one-shot one-launch project like this secret is not very
difficult if you just ruthlessly minimize the number of people involved.
Many people will realize that there's *something* funny about this
payload, but they won't know *what* the secret peculiarity is, and all you
need is one good cover story. (Read about the history of the SCORE project
sometime -- done in the more open society of the US, without even a serious
attempt at a cover story, it still took everyone by surprise.)
Henry Spencer
>Okay, how 'bout massive amounts of rocks being launched from the moon toward
>cities on earth. What about defending against that kind of ultra lo-tech
>assault?
Before you describe this as "ultra lo-tech", compute the amount of energy
needed to launch those rocks. It's huge.
George Allegrezza
[deletia]
>However, I am willing to fight a little harder on the idea of blasting
>parts of the moon with nuclear weapons and directing those blasts of rock
>toward the Earth. While all of you are correct that it is still wasting
>an awful lot of energy and we might as well just fire the missiles at
>earth.... one advantage to the multiple projectile theory (whether moon
>rocks or missiles) is that the earth probably could not defend against it.
> But whereas it would cost a fortune to create hundreds or thousands of
>reentry vehicles to barrage the earth at one time, a minimal number of
>missiles could be used to create a meteoric hailstorm from lunar material.
Without a credible ballistic missile defense system, which no nation on
Earth has at the moment, you wouldn't need hundreds of thousands of RVs,
just hundreds. It's that kind of problem that has kept people up late at
the Pentagon for the last 35 years or so.
The fictional country in your story would achieve its objectives more
quickly and at a significantly smaller cost if it built up its ICBM (or SLBM
or cruise missile) capabilities. It might even be able to do this in
near-total secrecy until it started weapon and flight testing. And, if it
were able to purchase tested nuclear warheads and ICBMs (from, for example,
one of the Soviet successor states), rather than develop its own, it might
be able to maintain its threat capabilities until it was ready to
announce/use them, thus maximizing their effects.
George
D L Jones
Heinlein got to that one first too. (see "The Man Who Sold the Moon").
His mistake was suggesting that someone might launch a mission to spread
black powder on the face of the moon to draw a figure. I rather think
something like titanium dioxide (very very white) would be more
effective, given that the Moon is almost black anyway.
marmiteman
Pat
Jmkistler <jmki...@aol.com> wrote:
>I have been rightly critiqued on the amount of energy needed to move the
>Moon. I am an author and not a scientist, and it was a crazy idea.
Yep!
>earth.... one advantage to the multiple projectile theory (whether moon
>rocks or missiles) is that the earth probably could not defend against it.
> But whereas it would cost a fortune to create hundreds or thousands of
>reentry vehicles to barrage the earth at one time, a minimal number of
>missiles could be used to create a meteoric hailstorm from lunar material.
What good does it do, if you end up wreckingyour home country also.
a weapon must be aimable or it's as large of a hazard to you as
anything else.
>
>My plan would be to use one large nuke to blast a huge amount of lunar
>material from the surface, and use smaller airblasts (nuke or
^^^^^^^^^
The moon is in a vacuum. Once the initial detonation is off, you only get
some radiation pressure on the particles. Not a phenomena i'd want to count
on for navigation purposes.
>conventional) all around to direct the rocks toward earth. If it worked,
>about five nuclear devices could send thousands of large projectiles at
5? try a whole lot more, i think. (WAG).
>the earth. The cost to benefit ratio of inflicting such a damaging attack
>using only five devices while overwhelming the enemies defenses seems to
>me to be quite high. While the earth would have two to three days of
>observing the trajectory of the incoming objects, they would have little
>chance of stopping them except by using high orbit or extra-orbital
>detonations to hopefully deflect or lessen the size of the approaching
>debris.
first of all, you need particles large enough to penetrate the
earth's atmosphere. most of the particles are going to be
very small. second you need to have a fine control on this.
maybe you could hit the russians with something like this, but
how do you safely threaten germany without enraging the french who
might then attack you? Also most countries are mostly empty space.
you could drop boulders on kansas all month and not hit a cow.
Imagine siberia.....
Third, the orbital mecahnics for this aren't simple. you need to
be able to make a directed burn towards the earth without error
and depending ont eh rocks not lofting in atmosphere and without
particle interactions pushing them off trajectory...
I don't know, sounds stupid to me.
--
I learned something here today. Nothing I do and Nothing I own
can remake the past -- Buaku
David M. Palmer
>Efficiency would be greatly improved by covering the same area with
>steerable solar reflectors. They don't have to be nearly as large as the
>microwave transmitters but they will need a long focal lenght. Then you
>can toast a city with, humm (15)^2/(1.5)^2, 100 times normal sunlight.
>Of coures you can only do this for about 1 week out ever 4 due to alignment
>problems and it's still a big easy target.
A flat mirror reflecting the Sun will produce a beam with a divergence
of half a degree (since the Sun is half a degree across). Using curved
mirrors would only make it worse. Therefore a moon-mounted mirror
system couldn't focus down to an area which is less than a few thousand
kilometers across. (By the same coincidence that makes Solar eclipses
so spectacular, the illuminated area on Earth is the same size as the
Moon.) Therefore, even if you totally covered the Moon with your
mirror system, you couldn't do more than get one additional Sun's worth
of illumination on a point on Earth.
Solar pumped lasers are not restricted by this limitation.
--
David Palmer
pal...@alumni.caltech.edu
dmpa...@clark.net
Bob Ssmith
>In article <ssmith.61...@paltech.com> ssm...@paltech.com (Bob Ssmith) writes:
>>Okay, how 'bout massive amounts of rocks being launched from the moon toward
>>cities on earth. What about defending against that kind of ultra lo-tech
>>assault?
>Before you describe this as "ultra lo-tech", compute the amount of energy
>needed to launch those rocks. It's huge.
The Saturn Vs weighed in at about 7 million pounds at liftoff. The same
amount of mass could be lifted from the moon with 1/20th the energy. At a
hunded pounds per rock, that 70,000 rocks.
Bob
Filip De Vos
: I have been rightly critiqued on the amount of energy needed to move the
: Moon. I am an author and not a scientist, and it was a crazy idea.
: However, I am willing to fight a little harder on the idea of blasting
: parts of the moon with nuclear weapons and directing those blasts of rock
: toward the Earth. While all of you are correct that it is still wasting
: an awful lot of energy and we might as well just fire the missiles at
: earth.... one advantage to the multiple projectile theory (whether moon
After smart rocks/brilliant pebbels, dumb rocks!
: rocks or missiles) is that the earth probably could not defend against it.
: But whereas it would cost a fortune to create hundreds or thousands of
: reentry vehicles to barrage the earth at one time, a minimal number of
: missiles could be used to create a meteoric hailstorm from lunar material.
This is just a special version of the observation, that offence
is easier than defence. If like when dealing with nukes, you want
to make the defence perfect, your cost rapidly becomes
astronomical.
: My plan would be to use one large nuke to blast a huge amount of lunar
: material from the surface, and use smaller airblasts (nuke or
^^^
No air there!! Maybe the side of the rock towards the
nuke would vaporise the rock, producing thrust.
: conventional) all around to direct the rocks toward earth. If it worked,
: about five nuclear devices could send thousands of large projectiles at
I suppose the yield would be low. Maneuvering a whole bunch of rocks
around by such a crude method will result in large amounts of rock
being blown out of the earth-moon system. Then again you don't care
about them.
: the earth. The cost to benefit ratio of inflicting such a damaging attack
: using only five devices while overwhelming the enemies defenses seems to
: me to be quite high. While the earth would have two to three days of
: observing the trajectory of the incoming objects, they would have little
: chance of stopping them except by using high orbit or extra-orbital
: detonations to hopefully deflect or lessen the size of the approaching
: debris.
Right! Remember the Scuds in the Gulf? They were succesfully
intercepted (at least some of them) but the bits (+ pieces
of Patriots) still fell down on the target areas.
: But still, I am no scientist. How would you go about deflecting or
: defusing such a situation?
Well.... I would hop aboard my antimatter rocket and head for my
place in the Troians! ;-)
Filip
Bob Ssmith
>jo...@uncc.edu (John Childers) writes:
>>Efficiency would be greatly improved by covering the same area with
>>steerable solar reflectors. They don't have to be nearly as large as the
>>microwave transmitters but they will need a long focal lenght. Then you
>>can toast a city with, humm (15)^2/(1.5)^2, 100 times normal sunlight.
>>Of coures you can only do this for about 1 week out ever 4 due to alignment
>>problems and it's still a big easy target.
>A flat mirror reflecting the Sun will produce a beam with a divergence
>of half a degree (since the Sun is half a degree across). Using curved
>mirrors would only make it worse. Therefore a moon-mounted mirror
>system couldn't focus down to an area which is less than a few thousand
>kilometers across. (By the same coincidence that makes Solar eclipses
>so spectacular, the illuminated area on Earth is the same size as the
>Moon.) Therefore, even if you totally covered the Moon with your
>mirror system, you couldn't do more than get one additional Sun's worth
>of illumination on a point on Earth.
How large "a point on earth," David? The gross solar input to the earth
(neglecting the earth's albedo) is on the order of 45 megatons equivalent PER
SECOND!
Bob
Joshua B Hopkins
Note, though, that only a very small fraction of the mass of the Saturn V ever
got going fast enough to get into orbit. Most of that mass was burned off
in the first few minutes. Therefore, your calculation is very inexact.
In addition, an untargeted one hundred pound rock entering Earth's
atmosphere poses essentially no danger to the human population. It will
burn up or explode in the upper atmosphere. If, by some coincidence, it
happens to reach the surface it is very unlikely to hit anything. If, by
some extremely unlikely coincidence, it falls on or near a building, the
inhabitants will simply pick it up an sell it.
I'm not even joking about the last line. Roughly two years ago a young
lady bought her first car - an old used one. Shortly after she bought it,
it was struck by a meteorite, which punctured the trunk and buried itself
in the driveway. She was, understandably, quite upset by the fact that her
"new" car had just been totaled by a completely random event. That is,
she was unhappy until a meteorite collector offered her significantly more
money for her meteorite than the car had been worth in the first place.
Jason Goodman
>What good does it do, if you end up wreckingyour home country also.
>a weapon must be aimable or it's as large of a hazard to you as
>anything else.
Well, if your home country is the Moon, who cares where the rocks go, as
long as it's "away". Not a good tool for taking out them pesky Russkies,
but maybe workable for taking out that annoying mother planet.
I agree that the problems with lack of nuclear airburst will be
difficult to overcome. If you have a mass driver on hand, you're
golden... Oops, that's Heinlein's idea. (Moon is a Harsh Mistress. Not
worth reading except for this idea.) Also, keep in mind that the point
of the exercise is to deposit a large amount of kinetic energy onto the
Earth's surface. So you need to toss at least as much mass as a
planet-killer asteroid... much more, actually, since the smaller pieces
will burn up more in the atmosphere.
Simon Rowland
power as you cite (a couple GW) for the moon-based death blaster ray
beam. That's about as much juice as is needed to power a poplation
500,000 city (give or take...).
Jmkistler
rocks toward earth. There is no air.
The idea I am getting at is that a bullet is directed on a straight and
narrow course through a rifle barrel based on the spiral grooves in the
rifle barrel. The spin caused by the rifling of the barrel provides the
projectle with a steady course. The purpose of my four or more airblasts
is to simulate rifling in a way: to send them on a fairly stable course
toward earth. But without air that is a problem.
Other critiques of getting the rocks off the moon are less problematic,
since nuclear blasts can be powerful and set from underground to create
boulders. Perhaps instead of using one large blast and then four
airblasts, a timed series of detonations within an existing large moon
crater would work, using the wall of the crater as a minimal sort of
gunbarrel. In other words, it would be a very short barrel, rather like a
sawed-off shotgun, but it might provide something of a directional to the
gases and debris ejected from ground-zero.
And I am only thinking about this for entertainment and discussions' sake.
I have no such plans nor do I think the moonbase would survive earth's
severe counterstrike. I just do not think the moon is entirely useless as
a stage for strategic strikes. We just need to be more creative and
imaginative in our planning.
Pat
Jason Goodman <good...@mit.edu> wrote:
>In article <435pt6$s...@clark.net> Pat, p...@clark.net writes:
>>What good does it do, if you end up wreckingyour home country also.
>>a weapon must be aimable or it's as large of a hazard to you as
>>anything else.
>
> Well, if your home country is the Moon, who cares where the rocks go,as
>long as it's "away". Not a good tool for taking out them pesky Russkies,
>but maybe workable for taking out that annoying mother planet.
Um okay, so you think people living ona fairly fragile moonbase
should make their primary offensive weapon involve exploding extremely
large sub-selenean explosives, and that this won't involve wrecking
the home country either? Lot's of that debris is also going to be in
low lunar orbit or in high earth orbit and be raining back down
for months or years. Not to mention the seismic shock problems.....
Uh Huh.. and that also assumes everyone on said moonbase is going to support
a genocidal war of destruction back at that mother planet.
what is it about MIT students that they seem to relish the idea of
murdering billions of people at one go? Yep, chalk this boy up to
the slobodan milosevic hall of fame.
> I agree that the problems with lack of nuclear airburst will be
>difficult to overcome. If you have a mass driver on hand, you're
>golden... Oops, that's Heinlein's idea. (Moon is a Harsh Mistress. Not
not minding the fact that he misses some fairly basic physics problems
along the way.
>worth reading except for this idea.) Also, keep in mind that the point
>of the exercise is to deposit a large amount of kinetic energy onto the
>Earth's surface. So you need to toss at least as much mass as a
>planet-killer asteroid... much more, actually, since the smaller pieces
>will burn up more in the atmosphere.
Even more, because the energy of a dinosaur killer asteroid is not
because of the earth's gravity well but because it's falling in
at cosmic velocities derived from the sun's gravity well.
so try tossing about 100 times as much mass if you want this effect
and the mass must be in a fairly small space-time window to get
through the atmosphere.
Jacob M McGuire
Moon: a.. by Jmki...@aol.com
> sake.
> I have no such plans nor do I think the moonbase would survive earth's
> severe counterstrike. I just do not think the moon is entirely useless
> as a stage for strategic strikes. We just need to be more creative and
> imaginative in our planning.
No, the moon is not entirely useless as a stage for strategic strikes,
but why go all the way to the moon when you can just go to North Dakota?
Sure is a hell of a lot cheaper....
+------------------------------------+-----------------+
| Small towns in western Germany are | Jake McGuire |
| usually about ten kilotons apart | mcg...@cmu.edu |
+------------------------------------+-----------------+
me...@cars3.uchicago.edu
to the moon, versus the one required to built an ICBM force on earth.
Mati Meron | "When you argue with a fool,
me...@cars3.uchicago.edu | chances are he is doing just the same"
Pat
Simon Rowland <si...@curtis.eagle.ca> wrote:
>Those CANDU reactors built dozens of years ago have at least as much
>power as you cite (a couple GW) for the moon-based death blaster ray
>beam. That's about as much juice as is needed to power a poplation
>500,000 city (give or take...).
yes,
now please solve the engineering problems for operating a CANDU
reactor in vacuum, low gravity, without a ready water supply...
also at the given costs of space transportation, please determine the
cost of transporting said reactor to the moon...
Pat
Jmkistler <jmki...@aol.com> wrote:
>airblasts, a timed series of detonations within an existing large moon
>crater would work, using the wall of the crater as a minimal sort of
>gunbarrel. In other words, it would be a very short barrel, rather like a
>sawed-off shotgun, but it might provide something of a directional to the
>gases and debris ejected from ground-zero.
you'd be better off looking at the theory of shaped charges and how
a crater would interact in this.
>And I am only thinking about this for entertainment and discussions' sake.
> I have no such plans nor do I think the moonbase would survive earth's
>severe counterstrike. I just do not think the moon is entirely useless as
>a stage for strategic strikes. We just need to be more creative and
>imaginative in our planning.
the moon is useless as a first strike platform but it would work well
for second strike missiles. let the dreaded followers of Xibo attack
our fair nation, our missiles on the moon will still destroy them.
if they attack the moon bases first, then we have warning here.
however the total cost of this platform would consume the national
production for a decade.
Kepa J. Lyman
On 11 Sep 1995, Jmkistler wrote:
>
> However, I am willing to fight a little harder on the idea of blasting
> parts of the moon with nuclear weapons and directing those blasts of rock
> toward the Earth. While all of you are correct that it is still wasting
> an awful lot of energy and we might as well just fire the missiles at
> earth.... one advantage to the multiple projectile theory (whether moon
> rocks or missiles) is that the earth probably could not defend against it.
> But whereas it would cost a fortune to create hundreds or thousands of
> reentry vehicles to barrage the earth at one time, a minimal number of
> missiles could be used to create a meteoric hailstorm from lunar material.
>
>
>
>
Why don't you just build a rail gun on the moon, and periodically
launch a ton of moon rock towards the earth? Once the missle had escaped
the moon's gravity, it would be all downhill. Small boosters (cheap)
could make final navigational corrections.
A note for a possible defense for earth for your story:
I read last year somewhere that there was a small (like 10 feet long)
missle that could deliver a payload to the moon by using the sun's
gravitational well. This device could be launched by airplane to nuke
any moon installation.
Kepa Lyman
Eric Pawtowski
Joshua B Hopkins <jbho...@ux4.cso.uiuc.edu> wrote:
>ssm...@paltech.com (Bob Ssmith) writes:
>
>it was struck by a meteorite, which punctured the trunk and buried itself
>in the driveway. She was, understandably, quite upset by the fact that her
>"new" car had just been totaled by a completely random event. That is,
>she was unhappy until a meteorite collector offered her significantly more
>money for her meteorite than the car had been worth in the first place.
>--
Admittedly, if there were hundreds or thousands of small meteors falling
all over the place, the value of any individual one to a collector would
go down rather dramaticaly.
Eric
--
epaw...@vt.edu----------------------------------------------------
Technicon 13 - SF&F return to SW Virginia! March 22-24, 1996.
Guests: Author L.E. Modesitt, Games designers Lori&Corey Cole,
Artist Ruth Thompson
Jane Mook
You could detonate a small 5 kiloton device inside of a large loop of
wire. That loop of wire would pick up about 1.5 kiloton equivalent
electrical pulse derived from the electromagnetic pulse of the expanding
plasma of the small nuclear warhead. 1.5 kilotons of TNT is equivalent to
60 trillion joules of energy.
The electrical pulse would be shorted out through any number of rails guns
to project metallic 'rocks' at high speed from the moon. Delay lines in
the rail gun array, which would be set up on some lunar plain, would
control timing of the discharge through the gun array, steering it.
To project something on a minimum energy transfer orbit to Earth from the
Moon requires it move at about 2,000 m/sec. That means each kg has about
2 mega joules. So, 60 trillion joules can lift 30 million kg, or 30,000
metric tons, of metal through this delta vee.
As the projectiles fall to earth they gain additional kinetic energy.
Arriving at the surface of the Earth they're moving at about 10,820 m/sec.
So the 30,000 metric tons contain about 1.756E15 joules of energy. This
is equivalent to about 44 Megatons of TNT.
Now, this will not detonate in the air. Most of this energy will be
released underground. There, plasma balls will erupt, spewing molten rock
and superheated gases across the surface. That is, the mechanical
connection to the buildings under fire will be about 10 times greater than
that possible through air.
So, instead of atmospheric overpressures causing the damage as in an
A-bomb air burst, these babies will cause significant shock waves through
the ground and shake the buildings down, rather than knocking them down.
Of course the expanding wave of molten and gasified rock will also knock
things down over shorter distances, and encase them in lava...
But, I wouldn't want to be around where these things were hitting!
Joshua B Hopkins
>On 11 Sep 1995, Jmkistler wrote:
>>
> Why don't you just build a rail gun on the moon, and periodically
>launch a ton of moon rock towards the earth? Once the missle had escaped
>the moon's gravity, it would be all downhill. Small boosters (cheap)
>could make final navigational corrections.
This has already been suggested many times in this discussion. The idea
doesn't work. A one ton moon rock is utterly harmless, and the facilities
large enough to launch anything dangerous are impractically large.
The only practical way to attack the Earth from Moon which anyone has
suggested so far is to use nuclear weapons, and this is still rather
challenging.
--
Josh Hopkins jbho...@uiuc.edu
The views expresed above do not necessarily reflect those of ISDS, UIUC AAE,
NSS, SEDS, IBM FSC, AISGC, MDSSC, NCSA, NMSU, AIAA, CSTS, NASA LeRC SPTD, BMDO,
or the American Association for the Advancement of Acronymphomaniacs
Sea Witch
>This has already been suggested many times in this discussion. The idea
>doesn't work. A one ton moon rock is utterly harmless, and the facilities
>large enough to launch anything dangerous are impractically large.
>The only practical way to attack the Earth from Moon which anyone has
>suggested so far is to use nuclear weapons, and this is still rather
>challenging.
One ton coming down from the moon is not harmless - it will burn up if
unshielded, but who says it has to unshielded? If I was on the moon
and had to bombard Earth for my survival, you can be //damn\\ sure
that I would encase the projectiles in heat shields. Not a difficult
problem.
Pierce Nichols
Steve Brinich
>calculation says one would need to melt a cube of ice 80 km on a
>side. Being overly optimistic, if we only need to raise the
>temperature of the ice 1 degree C to melt it, this requires roughly
>5*10^20 Joules.
It's much worse than that even in the best case. You forgot about the
heat of fusion (the energy input required to convert a solid into a liquid),
which for water is approximately 80 times that figure (the heat of fusion
for water is 79.71 cal/g; the heat required to warm it by 1 degree C is,
of course, 1 cal/g).
--
Steve Brinich | Term limits aren't enough. | PGP 89B992BB
ste...@digex.net | We need jail. | E67F7B2F64FD
GEnie: S.BRINICH | -- P. J. O'Rourke | F2EA14374C3E
John Napier
: >>In article <ssmith.51...@paltech.com> ssm...@paltech.com (Bob Ssmith) writes:
: >>>Solar-powered or nuclear-powered directed-energy weapons based on the moon
: >>>could lay waste enormous amounts of territory on the earth's surface within
: >>>matters of minutes.
: >>Diffraction and other forms of beam
: >>spreading over Earth-Moon distances are very serious obstacles.
<Major snippage of technical data.>
What I don't understand is why you would use a beam weapon at
the top of a big gravity well.
Given the old Urban Legend that dropping a penny off the Sears tower
(BT DT) it would embed itself into cement. I'd just throw rocks
at the Earth from space. Make 'em large enough so they dont
disintegrate and you have bombs more powerfull than the A-Bomb.
It was good enough to kill off the dinos.
Joshua B Hopkins
One ton *is* pretty much harmless, no matter what you do to it.
Even if the rock makes it to the ground intact, the ballistic coefficient
is too low, so the terminal velocity is lower, so the amount of energy
present is low. If you wrap a one ton rock in a thin layer of unobtainium
to be sure that it makes it through the atmosphere, it would create a crater
smaller than a city block. The amount of energy per unit mass isn't
much greater than what you'd get from a high explosive warhead. In other words,
a loaded F-15E is more far dangerous than a one ton rock dropped from the Moon.
The problem with rocks during reentry isn't just that they burn up, they
also aren't structurally strong enough. In the upper atmosphere the very high
pressure on the bottom and very low pressure on top of the rock apparently
cause meteors to "pancake" - i.e. flatten out. The drag increases, and the
thing just comes apart. Duct taping shuttle tiles on the surface would
make very little difference.
Sure, you could find ways around this. What would it take to make a rock
into a useful, targetable weapon?
*Re-entry heat shield to prevent undue mass loss or fragmentation
*Significant structural reinforcement
*Sensors or GPS-type recievers for target guidance
*Rocket system for trajectory control
Once you get all this stuff put together, you realize two things: 1) This
simple, dumb rock has become much more expensive and heavy, and 2) kinetic
energy isn't such a great way to deliver destruction. It's inefficient
at any scale smaller than armageddon.
I will say this once more, for those who still haven't figured it out.
No rock which can easily be launched from the Moon is a significant
threat. No rock which can plausibly be launched from the Moon is more
of a threat than a nuclear warhead.
If you really want to use kinetic energy weapons dropped from the Moon,
you have two options. If you want to go the route of simple, cheap
projectiles, a lump of rock or iron even with minor modifications like
a thermal protection system is going to have to mass tens or hundreds of
thousands of tons to be competitive with a nuclear weapon.
Alternatively, you could make your kinetic energy projectile from scratch.
Something like a tungsten spike would be a good choice. It's very dense, so
it won't slow down much, and its also quite strong and very comfortable
at high temperatures. However, making a 500 ton projectile out of tungsten
is easier said than done. For one thing, I can't imagine a lunar colony
having that much spare tungsten.
So, we're back to square one. A lunar colony which wants to fight a
war is far better off sending a nuclear warhead than anything resembling
a rock. Even chemical explosives are competitive with simple rocks.
William H. Mook, Jr.
flatbed trucks each carrying a cylinder of solid steel. Each cylinder
was about 4 feet in diameter and 5 feet long. Strapped down and secured
ont he flat bed they looked *heavy*. The big trucks groaned up hills and
slid around corners (there was construction and the highway had narrowed
to one lane for a few miles). I was glad to blast pass them when I
could. It looked like these cylinders could do serious damage if they
cut loose at 40 mph, let alone 20,000 mph!
Maybe its just me, and I may have said this somewhere before so excuse
me repeating it. When I imagine building a viable lunar city I also
imagine that building something like an atom bomb powered array of rail
guns (even with disposable rails) capable of lifting 30,000 tons at a
crack would be easy.
Besides, if I recall my Heinlein properly, in THE MOON IS A HARSH
MISTRESS, large numbers of electromagnetic launchers were already in
operation to sustain trade between earth and moon. So, the technology
for cheaply building guidance systems, ACS rockets, etc., were already in
place and were merely exploited in the war effort.
BTW: In sufficient quantities anything becomes cheap. For example,
accelerometers used to be heavy and costly items. But, with the advent
of air bags in automobiles, accelerometers became cheap, lightweight, and
more accurate. I can also imagine that what we consider costly today
might one day be cheaper than dirt. Laser gyros are a case in point.
The first ones were very expensive. But, there are solid state systems
in the works (according to Photonics Mag.) that will do for laser gyros
what air bags did for accelerometers. Who will buy millions of precision
laser gyros for $10 each? Virtual Reality gear makers of course.
Already there exist in labs solid state versions of missile guidance
systems on a chip. All the complicated stuff to make big chunks of
metal dangerous (I agree with you about little rocks) need not be that
complicated at all. For example, guidance systems have already been
studied where lasers are fired at big dumb chunks of orbiting debris.
These lasers boil off plasmas from a chunk of metal or plastic and the
reaction forces change the orientation or speed of the chunk in a small
way.
So, we could imagine a closed loop system that gets interrogated by a
coded microwave pulse, the microwave pulse powers a transmitter to chirp
back coded nav data. That data is interpreted and controls the firing of
a precise laser pulse (in the 10 MWatt range) to create attitude control
inputs for the big chunk of metal. The whole system is cheap compared to
the cost of the chunk of metal in the first place... and the chunk of
metal is presumably cheap compared to nuclear weapons...
BTW: I tend to favor shooting a cartload of microfission bomblets from
the moon. Antiproton boosted microfission can produce a 50GJoule blast
from milligram sized particles of Pu. Imagine a thousand tiny A-bombs
the size of Aspirin tablets fired from the moon. They would be invisible
and nearly impossible to detect or deflect. Their arrival is precisely
timed As they float down from the heavens they all detonate sort of
like a phased array. The destructive blast could even be directed the
same way a phased array radar beam is pointed. So, with enough points
you could construct a force holograph of the city you attacked by
controlling the timing of the explosion of each point....
The total mass of Pu need not be much larger than that used in a few
conventional warheads... but their destructiveness could be multiplied
through dispersal... to flatten large areas by shock waves from above.
Mark Lutton
>What I don't understand is why you would use a beam weapon at
>the top of a big gravity well.
>Given the old Urban Legend that dropping a penny off the Sears tower
>(BT DT) it would embed itself into cement. I'd just throw rocks
>at the Earth from space. Make 'em large enough so they dont
>disintegrate and you have bombs more powerfull than the A-Bomb.
>It was good enough to kill off the dinos.
It was good enough for Heinlein in "The Moon Is A Harsh Mistress."
--
-------------------------------------
Mark Lutton mlu...@world.std.com
Joshua B Hopkins
>I was driving to Cincinatti the other day and I passed a convoy of
>flatbed trucks each carrying a cylinder of solid steel. Each cylinder
>was about 4 feet in diameter and 5 feet long.
>It looked like these cylinders could do serious damage if they
>cut loose at 40 mph, let alone 20,000 mph!
As Henry Specer once said, "Belief is no substitute for arithmetic."
The steel cylinders you mention contain less than 2 cubic meters of
steel, and depending on the alloy they would weigh about 15 tons.
Meteors of this size are not uncommon (stone ones are downright
frequent, but metallic meteors are rarer) and they have never, ever,
destroyed a city block, let alone obliterated a city.
The catch (and the major fact that "high ground" people forget) is
that meteors don't hit the *ground* at 20 km/s, they hit the
*atmosphere* at that speed, and slow down quite rapidly. Earth
may be at the bottom of a gravity well, but it is well armored.
>Maybe its just me, and I may have said this somewhere before so excuse
>me repeating it. When I imagine building a viable lunar city I also
>imagine that building something like an atom bomb powered array of rail
>guns (even with disposable rails) capable of lifting 30,000 tons at a
>crack would be easy.
It would be neither easy nor smart. Launching with a rail gun
or maglev or coriolis launcher is much easier if you launch small
payloads frequently, rather than big payloads occasionally. 30,000
tons is not a small payload.
>Besides, if I recall my Heinlein properly, in THE MOON IS A HARSH
>MISTRESS, large numbers of electromagnetic launchers were already in
>operation to sustain trade between earth and moon. So, the technology
>for cheaply building guidance systems, ACS rockets, etc., were already in
>place and were merely exploited in the war effort.
Yeah, but that was a book. So what?
>BTW: In sufficient quantities anything becomes cheap.
This is only true for limited definitions of the word cheap. North
America used 253 exajoules of energy in 1992, and the world used
550 million tons of iron and steel in 1980. Despite that enormous
market, constructing and launching a 30,000 ton iron projectile
today would still cost more than a hundred million dollars *just* for
electricity and steel, even if the maglev or railgun or coilgun
were tossed in for free. There is a limit to the power of
mass production.
Steve Brinich
> Suppose you launch a 1 ton rock from the Moon, to hit earth (1 ton
>is equivalent in weigh to a real hefty, multimegaton warhead). Assuming
>that it arrives to Earth at roughly escape velocity (11.2 km/sec) and
>ignoring any slowing down in atmosphere (which is very significant) the
>energy on impact will be
>
> E = 10^3 /2 * (1.12*10^4)^2 = 6.27*10^10 Joule
>
>which is the equivalent of about 15 tons of TNT. Not much.
"Not much"?? I daresay there are generals who sell their souls
for the ability to drop 15-ton TNT bombs anywhere on the planet for the
cost of digging up a ton of rock and generating the power to launch it
from a lunar mass driver. ;-)
Bryon Sutherland
>Rocks are a lot cheaper and easier to find than multi-megaton warheads.
>Exactly the point of the original suggestion, as I read it. Not even in
>billion ton ranges. If you have the tech to drop aimed rocks from space,
>you have the tech to fetch asteroids and drop those.
How much would it cost for fuel to manuver a multi-thousand ton
asteroid? First you have to "catch" it and then propel it to
it's destination (at least until gravity took over). Probably cost as much
as a warhead.
Sorry if I am injecting reality into this discussion.
--
~
http://www.unt.edu/~bryon/
It's a brave new web
me...@cars3.uchicago.edu
>> In article <44vc33$n...@Mercury.mcs.com>, jna...@mcs.com (John Napier) writes:
>> >Given the old Urban Legend that dropping a penny off the Sears tower
>> >(BT DT) it would embed itself into cement. I'd just throw rocks
>> >at the Earth from space. Make 'em large enough so they dont
>> >disintegrate and you have bombs more powerfull than the A-Bomb.
>> >It was good enough to kill off the dinos.
>
>people would get stabbed by falling icicles, or is that a UL?
>
Well, somebody was killed by a falling icicle last year, in Chicago.
It didn't fall from Sears Tower, though.
me...@cars3.uchicago.edu
>me...@cars3.uchicago.edu wrote:
>: Check the numbers. Suppose you launch a 1 ton rock from the Moon, to
>: warhead).
>
>a Ford Ranger. Any reasonably sized rock (asteroid) would be more along the
>lines of a few hundred or few thousand tons.
>
>Rocks are a lot cheaper and easier to find than multi-megaton warheads.
>
>: (if it did) you need asteroid size masses, in the few billion ton
>: range.
>
>Exactly the point of the original suggestion, as I read it. Not even in
>billion ton ranges. If you have the tech to drop aimed rocks from space,
>you have the tech to fetch asteroids and drop those.
Well, not quite the point of the original suggestion. It dealt with
launching rocks from the moon, not catching asteroids and changing
their orbits. The level of technology involved is quite different.
Of course, we can follow on this one as a separate sub thread (BTW,
the idea is mentioned, in passing, in "The Mote in God's Eye" by Larry
Niven and Jerry Pournelle)
As for rocks being cheaper than warheads, the main cost incurred in
the case mentioned is in launch systems and guidance systems, the
warhead is negligible. Therefore, and that's my point, using current
launch technology or just a straightforward extrapolation of such,
you'll cause way more damage with warheads than with rocks.
me...@cars3.uchicago.edu
>>me...@cars3.uchicago.edu (Mati Meron) wrote:
>
> > Suppose you launch a 1 ton rock from the Moon, to hit earth (1 ton
> >that it arrives to Earth at roughly escape velocity (11.2 km/sec) and
> >ignoring any slowing down in atmosphere (which is very significant) the
> >energy on impact will be
> >
> > E = 10^3 /2 * (1.12*10^4)^2 = 6.27*10^10 Joule
> >
> >which is the equivalent of about 15 tons of TNT. Not much.
>
> "Not much"?? I daresay there are generals who sell their souls
>for the ability to drop 15-ton TNT bombs anywhere on the planet for the
>cost of digging up a ton of rock and generating the power to launch it
>from a lunar mass driver. ;-)
You forget the cost of a guidance system capable of delivering said
rock to your assigned target, with a precision of few tens of meters
(since for a hardened target, 15 ton of TNT beyond this radius will be
useless.
Pat
Steve Brinich <ste...@access.digex.net> wrote:
>>me...@cars3.uchicago.edu (Mati Meron) wrote:
>
> > Suppose you launch a 1 ton rock from the Moon, to hit earth (1 ton
> >is equivalent in weigh to a real hefty, multimegaton warhead). Assuming
> >that it arrives to Earth at roughly escape velocity (11.2 km/sec) and
> >ignoring any slowing down in atmosphere (which is very significant) the
> >energy on impact will be
> >
> > E = 10^3 /2 * (1.12*10^4)^2 = 6.27*10^10 Joule
> >
> >which is the equivalent of about 15 tons of TNT. Not much.
>
> "Not much"?? I daresay there are generals who sell their souls
>for the ability to drop 15-ton TNT bombs anywhere on the planet for the
>cost of digging up a ton of rock and generating the power to launch it
>from a lunar mass driver. ;-)
except add in the capital costs of the launch system, the rather slow delivery
rate and the amazing fragility of the launcher and you have something
financially devastating to the building nation and militarily insignificant.
realize that what you are talking about is equal to 15 one ton bombs
or what two F-15s deliver without waiting 3 days for the payload to
transit to target.
Pat
Graham R Pearson <cee...@cee.hw.ac.uk> wrote:
>> In article <44vc33$n...@Mercury.mcs.com>, jna...@mcs.com (John Napier) writes:
>> >Given the old Urban Legend that dropping a penny off the Sears tower
>> >(BT DT) it would embed itself into cement. I'd just throw rocks
>> >at the Earth from space. Make 'em large enough so they dont
>> >disintegrate and you have bombs more powerfull than the A-Bomb.
>> >It was good enough to kill off the dinos.
>
>Is it true that the plaza around the Sears Tower is closed in winter because
>people would get stabbed by falling icicles, or is that a UL?
wind.
when i was a kid, they used to have to put ropes out to allow people
to cross it. add ice and snow ont he ground and it's probably too
dangerous to use.
falling ice is a hazard, but not the only one.
Joseph Askew
> "Not much"?? I daresay there are generals who sell their souls
>for the ability to drop 15-ton TNT bombs anywhere on the planet for the
>cost of digging up a ton of rock and generating the power to launch it
>from a lunar mass driver. ;-)
I doubt it. Not if they have to wait four days for it to
arrive. Not that the cost of that power is insignificant
either. Let alone the mass driver and the support for it.
Joseph
Adam Felson
: me...@cars3.uchicago.edu wrote:
: Assuming your figures are correct - I haven't checked them yet, 15 -
: tonnes of TNT is still a lot, and there's a virtually unlimited supply
: of rocks in the moon. Given that the launch site is kept secret, the
: amount of damage done could be horrific. 15 tonnes of TNT will not
: flatten whole cities - but it willcause a lot of disruption, esp. if
: there's a habit of sending 2 or 3 in a row. There'd be a terrible rush
: to get out of the city. Major probs.
Not really. An H-bomb, which is thousands of times cheaper than
mucking around with moon rocks, can deliver a blast of 15 MILLION tons of
TNT.
Simon Rowland
>(if it did) you need asteroid size masses, in the few billion ton
>range.
Hmmm...
It reminds me of a (Zubrin?) mars teraforming paper I read. It
involved blasting Mars with some comets rich in greenhouse gasses (ie
methane, etc). Apparently, with the help of gravity assists, only about
300 m/s need be imparted on the body in question to get it to Mars. A
fission pile using the asteroid as propellant would do the trick. Or
maybe exploding nukes to nudge it in the right direction.
The comet could be redirected to Earth.
Joshua B Hopkins
>In article <45chdt$7...@access1.digex.net>,
>Steve Brinich <ste...@access.digex.net> wrote:
>>>me...@cars3.uchicago.edu (Mati Meron) wrote:
>>
>> > Suppose you launch a 1 ton rock from the Moon, to hit earth (1 ton
>> >is equivalent in weigh to a real hefty, multimegaton warhead). Assuming
>> >that it arrives to Earth at roughly escape velocity (11.2 km/sec) and
>> >ignoring any slowing down in atmosphere (which is very significant) the
>> >energy on impact will be
>> >
>> >which is the equivalent of about 15 tons of TNT. Not much.
>>
>> "Not much"?? I daresay there are generals who sell their souls
>>for the ability to drop 15-ton TNT bombs anywhere on the planet for the
>>cost of digging up a ton of rock and generating the power to launch it
>>from a lunar mass driver. ;-)
>except add in the capital costs of the launch system, the rather slow delivery
>rate and the amazing fragility of the launcher and you have something
>financially devastating to the building nation and militarily insignificant.
There's an even simpler objection. The calculation above determines the
energy the rock has when it reaches the upper atmosphere, *not* when it
reaches the ground. Even if a one ton rock reached the ground (which
it wouldn't), it would be moving much more slowly. Since kinetic energy
is a function of the square of velocity, even a small drop in speed is
significant. The final result is that small rocks or rock-like objects
(by small, I mean less than, say, 100 tons) are barely competitive with
conventional explosives of the same mass.
One last time: Reasonable sized rocks launched from the Moon just
aren't very dangerous.