Congressional candidate: Moon-colonizing companies could destroy cities by dropping rocks

[Elderberry]

You would have to propel that rock with a sizeable amount of energy so that it would impact the earth and not just orbit around it. How much energy was required for the Apollo vehicles to return to the earth? And they were by no means  city destroyers. Any city destroying rock is going to have to be accelerated with a huge amount of energy.

[bigheadfred]

Footfall, The Moon is a Harsh Mistress, and a few (IIRC) John Ringo novels.

@EC

Hammer of God was an asteroid, I think, A. C. Clarke. It wasn't Hammer of the Gods.

Lucifer's Hammer was one. I think there was a similar Greg Bear book.

[Ghost Bear]

Lucifer's Hammer.

Lucifer's Hammer was a big comet that hit Earth, completely natural.  Footfall featured the attacking aliens dropping rocks to take out centers of human opposition.

As others have pointed out, in The Moon is a Harsh Mistress the Loonies repurposed the mass drivers meant to send raw materials to Earth into bombardment cannons.

Kinetic bombardment a.k.a. "Project Thor" a.k.a "Rods from God" was one of the advanced weapons concepts thought up by the Air Force during the "Star Wars" push in the late-80s. Jerry Pournelle talks about it in a couple of places on his blog.

[bigheadfred]

Lucifer's Hammer was a big comet that hit Earth, completely natural.  Footfall featured the attacking aliens dropping rocks to take out centers of human opposition.

As others have pointed out, in The Moon is a Harsh Mistress the Loonies repurposed the mass drivers meant to send raw materials to Earth into bombardment cannons.

Kinetic bombardment a.k.a. "Project Thor" a.k.a "Rods from God" was one of the advanced weapons concepts thought up by the Air Force during the "Star Wars" push in the late-80s. Jerry Pournelle talks about it in a couple of places on his blog.

Thanks for the clarification. I've read a lot of books and can't seem to keep them all straight in my head anymore. Forgetful.

[Ghost Bear]

Thanks for the clarification. I've read a lot of books and can't seem to keep them all straight in my head anymore. Forgetful.

You're welcome.  ^-^ I have the same problem, especially with books that I read as a kid. Sometimes I'll start reading something and think, "This is very familiar...."  and it's because I read it before.   

[bigheadfred]

You're welcome.  ^-^ I have the same problem, especially with books that I read as a kid. Sometimes I'll start reading something and think, "This is very familiar...."  and it's because I read it before.   

I went and looked. I have Lucifer's Hammer and Footfall. 

[r9etb]

You would have to propel that rock with a sizeable amount of energy so that it would impact the earth and not just orbit around it.

Actually, no... it's easier to crash into the Earth than to put something in orbit about it.

How much energy was required for the Apollo vehicles to return to the earth? And they were by no means  city destroyers. Any city destroying rock is going to have to be accelerated with a huge amount of energy.

The Apollo vehicles approached Earth at something north of 24,000 mph, which represents a whopping kinetic energy.  All of that energy was bled off into the atmosphere by the ablative heat shield.  Had they gone straight through the atmosphere without burning up, they'd have left a very large crater.

[bigheadfred]

Actually, no... it's easier to crash into the Earth than to put something in orbit about it.

ain't that the truth

[Ghost Bear]

I went and looked. I have Lucifer's Hammer and Footfall. 

They are both great books!  I re-read each of them every few years.

I mean, deliberately... not just by accident. 

[bigheadfred]

They are both great books!  I re-read each of them every few years.

I mean, deliberately... not just by accident.

The Greg Bear I was thinking of are Eon and Legacy. Sorta like Rama. Sorta not.

[geronl]

Was that Footfall? Hammer of the Gods? I can't remember.

@Jeff Head included it as a weapon system in his book!

[geronl]

Actually, no... it's easier to crash into the Earth than to put something in orbit about it.

The Apollo vehicles approached Earth at something north of 24,000 mph, which represents a whopping kinetic energy.  All of that energy was bled off into the atmosphere by the ablative heat shield.  Had they gone straight through the atmosphere without burning up, they'd have left a very large crater.

aiming it might be a bigger challenge

[Smokin Joe]

I was shooting for tactical. Like dropsies. Any dang fool can play planet killer.  ^-^

What-evurrrr!

I didn't mean that big. Just enough to give it an effective radius a couple times the diameter of the target area.  It isn't like someone on the moon is going to throw rocks at Monaco or Lithuania, they'll be aiming at a bigger target, anyway, like Helmland Province, or Guangdong, or Yemen. If it's smaller than that, nuke it from orbit...

[Joe Wooten]

Brianna Wu, a Dem, claims that Moon valuable militarily because rocks ‘have power of 100s of nuclear bombs’


A transgender-issues activist and Democratic candidate for Congress says the advent of the space tourism industry could give private corporations a “frightening amount of power” to destroy the Earth with rocks because of the Moon’s military importance.


Brianna Wu, a prominent “social justice warrior” in the “Gamergate” controversy who now is running for the House seat in Massachusetts’ 8th District, suggested in a since-deleted tweet that companies could drop rocks from the Moon.


“The moon is probably the most tactically valuable military ground for earth,” the tweet said. “Rocks dropped from there have power of 100s of nuclear bombs.”
SpaceX announced Monday it is planning to launch a tourism venture to the Moon in 2018.


Read More: http://www.isn-news.net/2017/03/congressional-candidate-moon-colonizing.html

Brianna Wu is a complete nutcase starting with the fact he is no woman. He is a surgically/chemically mutilated eunuch who thinks he's a woman.

[r9etb]

aiming it might be a bigger challenge

Not at all -- it's a straightforward launch window computation.

[Joe Wooten]

Not at all -- it's a straightforward launch window computation.

Sure, but you will need mid-course corrections in all likelihood.

[Cripplecreek]

Not at all -- it's a straightforward launch window computation.

You don't really run into any really unpredictable variables until you hit the atmosphere of earth.

Your speed is high enough that wind direction is meaningless. It really comes down to whether the rock will impact the surface, explode in the air, and if it explodes in the air will it be at a low enough altitude to do serious damage.

Plenty of titanium oxide on the moon, Is titanium resistant to extreme heating at hypersonic speeds?

[r9etb]

You don't really run into any really unpredictable variables until you hit the atmosphere of earth.

Midcourse corrections are reasonable.  There's probably not enough time in-atmosphere to make significant corrections, but re-entry bodies are steerable.

Your speed is high enough that wind direction is meaningless. It really comes down to whether the rock will impact the surface, explode in the air, and if it explodes in the air will it be at a low enough altitude to do serious damage.

Plenty of titanium oxide on the moon, Is titanium resistant to extreme heating at hypersonic speeds?

Here you've hit upon the re-entry body problem -- it's a matter of heat dissipation vs. speed vs. time.  Manned bodies are blunt.  Missile warheads are sharp.  For both cases, the heat dissipation works -- it's the angles in the middle that are problematic.  (The seminal paper on the topic is here: https://web.archive.org/web/20151013182336/http://naca.central.cranfield.ac.uk/reports/1958/naca-report-1381.pdf)

So a warhead-shaped projectile would be the proper choice.

[Smokin Joe]

You don't really run into any really unpredictable variables until you hit the atmosphere of earth.

Your speed is high enough that wind direction is meaningless. It really comes down to whether the rock will impact the surface, explode in the air, and if it explodes in the air will it be at a low enough altitude to do serious damage.

Plenty of titanium oxide on the moon, Is titanium resistant to extreme heating at hypersonic speeds?

Titanium dioxide (Rutile) melts around 1800 degrees C.

[Smokin Joe]

Sure, but you will need mid-course corrections in all likelihood.

It all depends on how 'surgical' you want the strike to be. If you have enough rock, say an anticipated radius of destruction 2 times the diameter of the intended target area or more, your success is more likely than just throwing something intending to take out a smaller area. in a situation where 'surgical' might mean the elimination of a major metro area, a little slop might get an extra country or two (thinking Europe or Africa, for instance). In larger countries an extra state or province. If you want precision, I'd think it would take something smaller, likely manufactured rather than cut loose as a chunk, and that can be maneuvered, both inbound, and possibly in atmosphere. (The 'Rods from god' approach to kinetic apocalypse.)

[Cripplecreek]

Titanium dioxide (Rutile) melts around 1800 degrees C.

Then Tungsten it is.

[Smokin Joe]

Then Tungsten it is.

Just factor in the ablation. Send some little ones over and see where they burn up...contact mass should be relatively calculable.

[Elderberry]

The meteor that crashed into Russia  was estimated to be about 55 feet in diameter, weighing 100,000 tons, at a speed of 46,000 mph, and had an energy of 500 kilotons, about 25 times the energy of “Fat Man” that exploded over Nagasaki.

http://www.dailymail.co.uk/news/article-2280920/Meteor-crashed-Russia-largest-space-rock-hit-earth-century-claim-scientists.html

What would the size and speed of Brianna Wu’s rock be to have the energy of 100’s of nuclear bombs?

[r9etb]

The meteor that crashed into Russia  was estimated to be about 55 feet in diameter, weighing 100,000 tons, at a speed of 46,000 mph, and had an energy of 500 kilotons, about 25 times the energy of “Fat Man” that exploded over Nagasaki.

http://www.dailymail.co.uk/news/article-2280920/Meteor-crashed-Russia-largest-space-rock-hit-earth-century-claim-scientists.html

What would the size and speed of Brianna Wu’s rock be to have the energy of 100’s of nuclear bombs?

For reference, a 1000 kg rock traveling at the speed of Apollo 13 (~40,000 kph) has the energy of about 1.5 tons of TNT.  You'd need a mass of 5000 kg to reach 1 kT.

[geronl]

"Brianna Wu" is an avowed mentally ill nutcase, not just your regular nutter