From: curt@quest.UUCP (Curtis Gibson)
Subject: Wrecking an O'Neill (Was: Re: Wrecking a Planet)
Organization: Quest Research, Inc.
Date: Fri, 08 Jan 1993 20:50:52 GMT

>rwallace@unix1.tcd.ie (russell wallace) Writes:
>As I explained in another article, a piece of gravel is not at all going
>to drill a hole in a 1 billion ton O'Neill habitat. Even if it did, the
>population presumably have sealed compartments to get into during raids.
>Plus, your attack carrier will have to get reasonably close to throw the
>gravel. Probably within range of the defensive armament, plus the
>defenders will have interceptors, as well as lots of civilian ships that
>can be armed and used as interceptors.
>
>--- early posts omitted ---
>
>The habitat's defensive armament (which can be of almost any desired
>size and power output) can simply vaporize the rock a long way away.

If your 1 billion ton habitat is like the ones I'm familiar with from
all my reading, its a cylinder or sphere around 1 km in diameter.  
The cylinder type is 3 to 5 diameters long.  It is spun to supply
artificial gravity. Its main axis is lined up to the sun.  It has 3
BIG windows, (1/3rd the circumference wide) in the sides, with big
petal like mirrors to reflect sun light inside.  Thats 1/2 of the 
inside area is windows.  It will be paired with a twin for stability.
The end pointed at the sun will have the thickest rock and soil rad
shield, maybe 10 m thick.  The 10 m rad shield will aford a 99.9999
protection against hard radiation, figured from the rule of 90 %
reduction per 5 feet or 2 m of rock/soil.  Else where there will be
about 3-4 m of rock/soil for a 99.99 protection.

There will be rivers and streams, ponds and lakes, trees, srubs and
grass.  A wonderful place to live, I'll be the first to rent/buy a
home on one.  But if someone is shooting at it, its the last place
I'll want my tender little pink butt to be.

We have artillery shells that will penetrate 10 m of rock/soil 
to smash bunkers.  They are only travelling about 1000 m per
sec to do that.  Any thing that get thrown/shot at the habitat
is going to be going a lot faster, maybe on an order of 100 times 
faster.  The rad shield is not going to keep out anything trying to
get in.  And remember, 1/2 the area is window.  No 10 m or even 3-4
m of rock/soil.  I can think of the problems of fusing the projectiles
to keep them from passing clear thru the habitat before they explode!

Senearo 1.
We attack from sunward to mask ourselves in the powerful signal of
the sun.  Their IR and radar is blinded.  We launch from 500,000 km
out a salvo of 12 missiles at each habitat in the pair.  They are
going to be travlling at 2 or 3 times the orbital velocity of the
habitats.  Flight time is under a day or 2.  (Wheres an envlope when
you need one 8^)).  As the missiles close with the habitats they are
still hidden in the sun.  But as the missiles get very close they are
bound to be detected.  Decoys and jammers are deployed.  The pack
starts to bob & weave with the decoys and jammers.  The defenders
start to take a toll of the decoys, jammers and the missiles.
They have to shoot fast, the missiles are very close now, there are
very few left.  The defenders destroy the last missile, huzzah!!!
The habitats are saved!  But wait, all that junk from the missiles
is still out there, speeding towards them at 100,000 m per sec.
(I'm making a guestamint here 8^)).  The defenders have a few bad
moments then remember they have 10 m of rock/soil the stop the junk.
There is going to be some damage, but nothing serious.  The junk
starts to hit.  Then a window explodes! followed by the other
2 windows.  Guess what happens when a big chunk of missile
penetrates the habitat going hypersonic?  The shock wave will blow
out your windows as sure as an explosion.

I submit that O'Neill habitats are not invulnerable.  They got windows.

Curtis S. Gibson   curt%quest.UUCP@cs.umn.edu