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Cis-lunar space is no place to get whanged
July 28, 2006 11:18 AM   Subscribe

War in Spaaaaaaaacccccce! A practical discussion of weapons that would work in space and orbital combat.
posted by Divine_Wino (42 comments total) 11 users marked this as a favorite

 
This is an intensely long, intelligent piece on the possibilities of doing violence to each other once we escape these earthly chains. Illustrated with some excellent sci-fi covers and other art. It sometimes descends into physics gobbledegook that I cannot understand but I'm sure some of you can. Do what I did and just skip those parts. It's the future of how we'll hurt each other, neat!
from the good folks at Atomic Rocket, via
posted by Divine_Wino at 11:19 AM on July 28, 2006


Semi-off-topic: as our energy surplus vanishes, the likelihood of getting into space in any meaningful way vanishes with it. The window for this particular civilization to slip the surly bonds of Earth is closing.
posted by George_Spiggott at 11:36 AM on July 28, 2006


That's when we go with the Orion drive, George, like in Footfall. Just like lettin' off firecrackers under a coffee can only many orders of magnitude more demeneted. Plenty of nukes laying around.
posted by Divine_Wino at 11:47 AM on July 28, 2006


Cool site. I’d like to think though that, given the harsh environment of space, we wouldn’t be shooting at each other for a while.
posted by Smedleyman at 11:49 AM on July 28, 2006


Exactly... years of peaceful exploration, science, humanity and then blammo solar system wide sissy-fight like two skinny old bikers tanked on tang screwdrivers slappin' at each other in the parking lot of the Beef Baron in Bethlahem, PA.
posted by Divine_Wino at 11:53 AM on July 28, 2006 [1 favorite]


Smedleyman writes "Cool site. I’d like to think though that, given the harsh environment of space, we wouldn’t be shooting at each other for a while."

That reminds me of Shismatrix. Since everyone is living in fragile structures in a vacume, things like projectile weapons are considered taboo. One stray bullet can kill an entire culture.

Fun link.
posted by brundlefly at 11:56 AM on July 28, 2006


I'll settle for Heim Effect propulsion. All you need is a suitably powerful electromagnet, and space and time will literally bend over backwards for you.

Any way, I'm disappointed to find no solution to the silence of space in this article. Of what use are point-defense beam weapons if they don't make cool kshewww! kshewww! sounds?
posted by Iridic at 11:58 AM on July 28, 2006


The vintage covers really bring the site together.
posted by absalom at 12:04 PM on July 28, 2006


If I didn't have such a spacewar boner I would have pointed out the whole site is a howto, thus:

Your imagination has been captured by the roaring rockets from Heinlein's SPACE CADET or the Polaris from TOM CORBETT, SPACE CADET. But are such rockets possible? How does one go about defining the performance of these atomic-powered cruisers?

This document gives some hints and equations that will allow back-of-the-envelope calculations on such matters. Though horribly simplistic, they are far better than just making up your figures.

...

posted by Divine_Wino at 12:15 PM on July 28, 2006


The Kinetic Kills section reminded me of a book I read a long time ago. Essentially a poorly armed group was trying to take on a very well armed opponent. The poorly armed group had no missiles or lasers or whatever it was that the Evil Empire baddies had.

So they stayed way out of range and used mass drivers to fire hundreds of thousands of ball bearings at the enemy ships. The ball bearings acted like micro-meteorites and devastated the enemy fleet.

It was a neat hard-ish science solution to space warfare.
posted by quin at 12:25 PM on July 28, 2006


Are there any sites out there giving thought to the idea of how ships would plan maneuvers in space-war? Given near-unlimited visibility and limited manuverability, one imagines a "dogfight" between two spacecraft would look very, very different from any concept of a "dogfight" in air combat, or even the newtonian model from B5.

I once read a novel that discussed this, but I can't place it anymore. I remember that most of the spaceships were large cylinders that lobbed kinetic and laser weapons at eachother during their closest orbital approach, but I can't remember the title, author, or any other details. Sounds like a future AskMe... (I remember the spacefighters answered to "Wombat Control," if that rings any bells. Google's got nothing relevant.)
posted by Alterscape at 12:29 PM on July 28, 2006


Uh, the law of conservation of energy states that energy just gets transferred, it doesn't diminish. So I'm not sure you can say our energy surplus is diminishing. In fact, you can't really say we have a "surplus".
posted by tadellin at 12:35 PM on July 28, 2006


Mass drivers - if you want to see the effect of mass drivers on a planet, Babylon 5 does it fairly well (in episode 2x42 "The Long Twilight Struggle). One of the most horrific episodes, IMO, just for barbarity equalling the amount of destruction. The Centauri ring their ships around the Narn home world and proceed to beat the shit out of the planet with asteroids, causing a nuclear winter scenario and killing most of the population.
This page reminds me of the Science Essays that one fan did for B5, working out how much power the various weapons had, along with ship sizes and stuff. I've always liked geeking-out with intelligence. Sometimes it can actually get you girls! Well... at least get them a little interested, in my experience.
Wicked find D_W, this'll help my Ultimate Plan For Galactic Conquest&#153 move along that much smoother.
posted by Zack_Replica at 12:48 PM on July 28, 2006


I remember looking into the possibilities of a mass driver as a bombardment platform, and while it can be a fearsome kinetic-energy weapon, to my surprise it would likely suck at maritime interdiction unless the launch crew achieves total Pearl-Harbor surprise. A ship with the newest Aegis suite could probably evade a real big rock coming down on it if they can detect it in time, for many values of "real big" and "in time." That 8000-metric-ton lump of sped-up white-hot refined lunar metal coming down from 500 mi up ain't gonna hurt your Arleigh Burke-class destroyer if the folks in CIC detect the incoming lump high enough up. If the ship has enough warning, they go to flank speed and move 10,000 yards away in less time than it takes for said lump to come all the way down, then they get to watch an amazing splash. (Land targets, though, would get pasteurized.)

(On preview -- Alterscape -- are you thinking of The Mote in God's Eye and The Gripping Hand?
posted by pax digita at 12:48 PM on July 28, 2006


ummm. the "&#153" is supposed to be the 'TM' symbol. dunno why it's not showing..
posted by Zack_Replica at 12:49 PM on July 28, 2006


tadellin writes "Uh, the law of conservation of energy states that energy just gets transferred, it doesn't diminish."

No, it doesn't.
posted by signal at 12:50 PM on July 28, 2006


Cause this shit right here is creative commons, m'man!
posted by Divine_Wino at 12:53 PM on July 28, 2006


Let there be
War in Space
And let it begin
With me.

posted by squalor at 12:53 PM on July 28, 2006 [1 favorite]


Many Bothans died to bring us this information.
posted by brain_drain at 12:58 PM on July 28, 2006


Are there any sites out there giving thought to the idea of how ships would plan maneuvers in space-war? Given near-unlimited visibility and limited manuverability

Visibility may be unlimited, but space is big and ships are small and hard to see. I'd expect emissions control and other stealthing to be very prominent parts. Active ranging just makes you a big, giant target.

Model: sub vs. sub combat.
posted by ROU_Xenophobe at 1:20 PM on July 28, 2006


In Forever War, Joe Haldeman wrote that "at .99c it doesn't matter if you get hit by a missile or a spitball."

And he's right. Beam weapons would be very very difficult to hold on target across astronomical distances, but a bucketful of relativistic BBs will make a mess out of anything. The closer to C you get, the more mass you carry.

"If the ship has enough warning, they go to flank speed and move 10,000 yards away in less time than it takes for said lump to come all the way down, then they get to watch an amazing splash."

Um, no. An 8000-tonne object (no matter what it's made of) moving at meteorite velocity is going to make one helluva lot more than an "amazing splash." It would liberate as much energy as a large nuclear weapon. Have you ever been to Meteor Crater?

Kinetic energy^ increases as the square of the velocity.

Also note such an actual impact would create a very, very large wave.
posted by zoogleplex at 1:24 PM on July 28, 2006


Any way, I'm disappointed to find no solution to the silence of space in this article. Of what use are point-defense beam weapons if they don't make cool kshewww! kshewww! sounds?” - posted by Iridic

Ach! Don’t be daft! You broadcast that to the other ship’s speakers corrected for doppler shift. Unless you’re at war with the JAXA, then you leave a short delay for speech.
posted by Smedleyman at 1:47 PM on July 28, 2006


posted by George_Spiggott: Semi-off-topic: as our energy surplus vanishes, the likelihood of getting into space in any meaningful way vanishes with it. The window for this particular civilization to slip the surly bonds of Earth is closing.

Dude, didn't you hear about the space elevator?
posted by zonkout at 1:56 PM on July 28, 2006


Still need a pretty big rocket - and all the industrial/chemical and logistical apparatus and experts it takes to build and launch one - to lift the "starter pack" for the SE out to geosynchronous orbit. It's not like you can string the thing up from the ground!
posted by zoogleplex at 2:05 PM on July 28, 2006


Uh, the law of conservation of energy states that energy just gets transferred, it doesn't diminish. So I'm not sure you can say our energy surplus is diminishing. In fact, you can't really say we have a "surplus".

I wasn't talking about physics, I was talking about the available, exploitable energy, on this planet. In much of the 20th century, we had access to as much energy as we could possibly use, and the public would entertain the space program. But when we start having blackouts and rationing, nobody's going to stand for it. Even though there is a limitless supply of energy avaialble in the rest of solar system in countless forms, the huge investment required to tool up to obtain and use it will be regarded as too costly.

Dude, didn't you hear about the space elevator?

Also expensive in terms of energy to build. And I'm pretty sure our current materials science is not up to it. Maybe when we can make nanocarbon tubes in bulk, if we ever can...
posted by George_Spiggott at 2:07 PM on July 28, 2006


I've always imagined the three main priorities for viable long term space deployment are extremely high tolerance shielding and speed for escape and evasion (and travel of course). And numbers of small, redundant ships as opposed to one large boat.

Basically, you'd want to be able to bear the brunt of any unforeseen attack, be able to scatter at speeds that would discourage pursuit and mitigate any losses through redundancy and decentralization. It would make the idea of attacking someone in space useless for the most part.
posted by effwerd at 2:13 PM on July 28, 2006


This is awesome! Thanks!
posted by cellphone at 2:24 PM on July 28, 2006


[this is good]
posted by Optimus Chyme at 3:09 PM on July 28, 2006


Good ideas, great cover art!
Silly as they are, plasma weapons are a popular SF concept that just won't go away.
Their main draw-back is that they won't work.

Plasma is the so-called "fourth state of matter", and is basically hot air.

Sci-fi explores and oft creates future inventions, yet is basically hot air.
posted by uni verse at 4:34 PM on July 28, 2006


ouch
posted by uni verse at 4:37 PM on July 28, 2006


zoogleplex, I used to make the same argument you did until I talked to a couple of naval officers who know more physics than I do (like that's real hard, tshyeahright).

We're not talking relativistic speeds, are we? If we are, then forget that poor little old US Navy destroyer; ze entire planet, she is focked, monsieur. I was thinking maybe a few thousand feet per second, tops, for a weaponized mass driver somebody could actually afford to build and then steer around in orbit to point at terrestrial targets. I've seen a figure of 30 km/sec mentioned in literature about mass drivers to get aluminum ore from lunar orbit to L5, but I bet an accelerator capable of accelerating 8k metric tons to that sort of speed would be pretty hard to aim at a ship less than 500 feet long with any kind of intended precision. I mean, Saddam Hussein could build an 800-mm supergun, but it was going to be a fixed emplacement, no?

(Holding in abeyance how you're going to acquire and track a 500-foot-long ship from that high up without counterdetection to warn the skipper he'd better move his boat -- yet avoid getting your own @$$ taken out preemptively -- but I digress...)

But at 10k yards, a warship with robust construction and compartmentation and competent damage control will probably be OK. I doubt that the subsurface impulse -- which would be far more intense than the above-surface one -- would be bad enough at that range to screw up the packing in the glands on the propeller shafts and cause noticeable flooding.

An atmospheric shock wave radiating out from the impact site on the surface. That means there might be a significant atmospheric blast off the initial surface strike -- something a warship should be able to withstand, not without damage, but 1/r^2 applies there, so certainly without catastrophe. At 10k yards, I'll grant that the atmospheric shock wave coming off the 8k t mass entering the atmosphere might repeat might redistribute some loose gear topside, maybe cause enough shock damage to knock antennas slightly askew, and cause the odd broken arms or ankle if somebody gets caught off balance.

Just because the raw kinetic energy of our hypothetical "dropped rock" is on the order of a small nuke doesn't mean it has the same effects. Where's the thermal pulse? Where's the EMP? Where's the blast? This is, essentially, a big-ass rock hitting water, not land, with a strong downward vector -- no big craters, and water absorbs shock energy somewhat better than land can. It's easy to read "kinetic mass = nuke" and think "my god, that ship's gonna die!" but this is not an actual nuke we're talking about, and I did stipulate the ship would probably get a head start on clearing datum. So don't confuse this theoretical impact with how nuke detonation behaves -- they're similarly energetic but not equivalent in how the energy gets distributed.

Most of the energy of a high-speed mass hitting the ocean will be transferred downward into the ocean through the "air/water interface" the surface, with all that nice energy-absorbing surface tension that has to happen if you're going to displace enough water to make an appreciable local wave, and it will propogate downward and outward through even more water -- an amazing volume, even though we're talking about an amazingly energetic impact. Most of the ocean open is deep enough that our hypothetical 9200-ton destroyer 5+ miles away might ride a rogue wave a little funny if it's beam-to, less so if it's bow- or stern-to. Tsunami-type waves in the deep ocean don't affect surface ships all that much apart from some broken china in the wardroom. Closer to shore, in a relatively shallow estuary or a confined waterway like the Scheldt, Hormuz or Gibraltar, all bets would be off, of course, but again, that ship would have to be pretty close in to get really messed up, and 10k yards is several miles. Compared to a nuke, essentially none of the energy is thermal or EM.

Now, if you got a Tunguska-like airborne explosion -- they think a meteor basically blew up while still in the air -- you'd get less subsurface effects and obviously more atmospheric ones, but one thing they learned from the Bikini test was that it's pretty hard to sink a ship outright by setting off a bigass explosion if the ship's a few miles off to start with. You can break a lot of stuff topside and screw up our theoretical destroyer a whole lot more with a big shock wave and scare the hell out of the crew -- maybe even manage a temporary "mission kill" -- but gravely damaging a ship or sinking it outright is a lot harder than people think.

(Now, if the mass does hit the ship, these two ossifers granted, everybody aboard is going to have a really bad day and the COMDESRON will be writing an awful lot of letters.)

I've had too many beers to run a calculator worth a damn & am doing this off the top of my head, so if you can produce figures showing I'm wildly wrong, then the next time I talk to those ship drivers, I'll be sure to say "zoogleplex said to tell you your math and physics skills suck, sir."
posted by pax digita at 8:05 PM on July 28, 2006 [3 favorites]


Now that ^^^^ right fuckin' there, is how you nerd out folks, take a lesson. Pax Digita I am in awe, good man yourself.
posted by Divine_Wino at 9:06 PM on July 28, 2006


"You might see fires, if reactive materials are escaping. But not convection flames, of course. "

Of course.
posted by ®@ at 10:11 PM on July 28, 2006


pax digita, you rock.
posted by brundlefly at 10:58 PM on July 28, 2006


And previously, his 3D starmaps page. Nyrath's pages provide a real service to the world.
posted by jiawen at 12:34 AM on July 29, 2006


Why's everybody got to be using rigid mostly-convex spaceships? By having a deformable body with the bulky bits separated from the center of mass, targeting becomes far more difficult, even with just a little rotation.
By keeping the masses connected, you don't have to burn propellant to maneuver.

That does make accurate thrust control difficult though.
posted by Tzarius at 5:05 AM on July 29, 2006


Naaah, I just jazz-riff a little. If I really rawked, I'd have started my initial post with all the relevant data precise to three sigfigs and included the relevant formulae, like the nuke ETs do when they're showing off their mad math-&-physics skillz. As Dad used to joke, "We do precision guesswork!"

But I wouldn't have a problem with my brother's youngest (her first cruise was on a Burke as an undesignated fireman) aboard that theoretical ship if it got 10k downrange from the computed probable point of impact. (She's pretty studly and hairy-assed for a lady sailor, anyhow.)
posted by pax digita at 7:01 AM on July 29, 2006


Re: mass drivers: What I'd like to know is what exactly would one use as a platform for such a beast. Whatever it is, it would also have to carry enough reaction mass to cancel out the "equal and opposite reaction effect" of launching the projectile from orbit, otherwise the platform is going to be putting itself into a higher orbit every time it is used. Then there is the issue of getting the platform over the target in a timely fashion -- just not going to happen with any current space technology.

Then you add in the logistics and cost of actually putting such a platform (or network of platforms) with it's payload into orbit, and it really just doesn't make a lot of sense as weapons concept outside of magical sci fi. It's much, much less expensive and difficult to just launch a missile from a land or airborne platform to destroy a target.
posted by moonbiter at 9:45 AM on July 29, 2006


"I've had too many beers to run a calculator worth a damn & am doing this off the top of my head, so if you can produce figures showing I'm wildly wrong, then the next time I talk to those ship drivers, I'll be sure to say "zoogleplex said to tell you your math and physics skills suck, sir.""

I concede your pwnership, sir! *bows abjectly*

I will have to retreat to my batcave and crunch numbers...

I think 30km/sec is pretty high, let's give it 5 km/sec and go from there. I'll try to be back later...
posted by zoogleplex at 10:27 AM on July 29, 2006


Whatever it is, it would also have to carry enough reaction mass to cancel out the "equal and opposite reaction effect" of launching the projectile from orbit, otherwise the platform is going to be putting itself into a higher orbit every time it is used.

That depends on the relative masses of projectile and firing vessel. If the platform is huge and the missiles are small, it'd hardly be any problem. For the same reason that a battleship doesn't automatically capsize when it fires a full broadside, an orbital platform firing projectiles wouldn't necessarily be affected much. (A little, of course, but then it might be easy enough to carry enough reaction mass for that.)
posted by jiawen at 5:46 PM on July 29, 2006


zoog, kewl! I'm curious to see what you get off of an 8kt mass. I wonder if it would slow any due to atmospheric braking, or do you want to use that as the terminal figure? Be sure to remember that I stipulated that ship gets 10,000 yards away from Pretty Big Splash in deep water; I'm assuming a negligible sea state too. I'm talking a flight Flight IIA Arleigh Burke and I'll give ya a beam-aspect (31 ft of draft) even though a smart skipper would want to try for a bow-on presentation. Even the Flight I Burkes are pretty survivable platforms, it turns out...
posted by pax digita at 8:42 PM on July 29, 2006


jiawen: This is true, but good luck getting a battleship-mass platform into orbit using any feasable modern or near-future boost technology (and explaining why the cost and effort is worth it to taxpayers when surface and air-based platforms can do the same job with different tools at a miniscule percentage of the cost).
posted by moonbiter at 1:29 AM on July 30, 2006


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