Orbital bombardment

[Destructionator XV]

What would orbital bombardment look like in a relatively hard sci fi setting (by that I mean no Star Wars style planetary shields or anything like that, but some leeway could be made for fancy tech), and more importantly, is there any defence to it?

I am thinking that small bullets would just burn up, energy weapon fire would probably be mostly absorbed by the atmosphere (I am guessing there; is that at all accurate?), and missiles would have a hard time in entry of the atmosphere, and would probably not connect.

But there is one thing that would definitely work: taking a big rock or something and tossing it at the planet. Is there anything the targets can do to defend themselves there?

Right now, I am thinking the only thing stopping that from happening is economy. Is it worth it to expend the energy driving the mass toward the planet? Do they have the mass to spare (probably; pick up a near earth asteroid and chuck it)?

The other thing is it would almost certainly cause quite a bit of collateral damage, and if you are going to capture something, you probably want it intact.

But assume the attacker is willing to accept the collateral damage. How practical are various forms of bombardment (mass driver, energy weapon, etc)? Is there any way to stop it? Could you stop it if you had some kind of theatre shielding technology, or would there still be too much collateral damage or something?

[Ra]

The so-called "Rods From God", or use of tungsten rods, would be reasonably accurate with advanced enough sensors, but unless your civilization is reasonably advanced (meaning not hard sci-fi, but softer sci-fi level), no orbital bombardment is going to get the kind of precision seen from, say, the Gulf War or the Iraq invasion. Even a 1 degree variation in your RFG turret could send your Rod off by dozens of miles; hardly accurate.

I personally still have my doubts that "Rods From God" wouldn't burn up in reentry as well anyway, so the idea I always had (though it's probably too complex and expensive) was to drop spherical high-explosive bombs with detachable heat shields like the Viking landers had. Then it'd basically be normal bombing, since your shielded bombs, once freed of the shields, could have fins and rocket guidance like modern bombs do. Unlike RFG's, they can be steered.

In fact... what if the bomb had little wings that folded out, allowing it to glide to the target? Your orbital bomb could then fly and adjust its course for possibly thousands of miles before reaching the target. That would be interesting.

As for interception, I suppose sufficently advanced lasers and targeting systems could shoot a bomb or even RFG down, but if you don't have them, then the orbiting ship could basically bomb you with complete impunity.

Asteroids would be a "quick and dirty" solution, but they would still require you landing something on them to attach engines, or attach cables, making that kind of resource-intensive as well.

[Stofsk]

Orbital bombardment would look like kinetic kill 'rods', nukes, and asteroids and antimatter planetkillers. The first two aren't necessarily 'end of the world' level, but the last two are potentially mass extinction level events.

[frigidmagi]

If your computers are good enough and fast enough, Interceptors can be used. Keep in mind no defensive system is going to be 100%, if they toss enough down at you, something will get through.

[Stofsk]

There isn't much you can do if the enemy has the high ground.

And if you go into relativistic projectiles through mass drivers, there may not even be enough time for you to bend over and kiss your arse good bye between finding out there's an array of mass extinction events heading at you at significant fractions of c.

[frigidmagi]

It does depend on a bit, but we're getting into a lot of maybes and ifs here. Course if they get to close, which I wouldn't recommend, they'll get shot at in turn. Railguns, missles, Energy weapons, etc, etc, etc.

[Kreshna Aryaguna Nurzaman]

Right now, I am thinking the only thing stopping that from happening is economy. Is it worth it to expend the energy driving the mass toward the planet?

If HUGEMOUNGOUS energy consumption is pretty much common for the sci-fi civilization (like in Star Wars, where even a fighter's laser cannon is in multi-megaton range), then it is definitely worth it. To such civilization, an orbital bombardment is pretty much nothing more than shore bombardments we have today.

Do they have the mass to spare (probably; pick up a near earth asteroid and chuck it)?

IIRC in HTTE trilogy, Thrawn pulled cloaked asteroids with tractor beam and rained them upon Coruscant. I don't quite remember the reason why he even bothered to do that, by the way, because SW already have Turbolasers for such purpose.

[Narsil]

The Algebraist by Iain M. Banks used asteroids launched at 'significant fractions of lightspeed' as a tool for planetary bombardment. I'll have to root out the book again, but it had an excellent quote about it.

[Batman]

Right now, I am thinking the only thing stopping that from happening is economy. Is it worth it to expend the energy driving the mass toward the planet?

If HUGEMOUNGOUS energy consumption is pretty much common for the sci-fi civilization (like in Star Wars, where even a fighter's laser cannon is in multi-megaton range), then it is definitely worth it. To such civilization, an orbital bombardment is pretty much nothing more than shore bombardments we have today.

It's also not particularly hard SF anymore and if you have that much energy to spare, why bother with the asteroid? Especially that in a culture that advanced the asteroid is likely going to be blown to smithereens long before impact? And it's multi-KT.

Do they have the mass to spare (probably; pick up a near earth asteroid and chuck it)?

IIRC in HTTE trilogy, Thrawn pulled cloaked asteroids with tractor beam and rained them upon Coruscant. I don't quite remember the reason why he even bothered to do that, by the way, because SW already have Turbolasers for such purpose.

Is's because your memory is several parsecs off. Thrawn didn't bombard Coruscant with the asteroids, he cloaked them and parked them in orbit meaning the NR couldn't risk lowering Coruscants planetary shield, effectively cutting off any traffic to and from the planet.

[Stofsk]

It does depend on a bit, but we're getting into a lot of maybes and ifs here. Course if they get to close, which I wouldn't recommend, they'll get shot at in turn. Railguns, missles, Energy weapons, etc, etc, etc.

Are you talking about shooting at relativistic projectiles? There's nothing you can do. By the time you've detected them, there's not enough time to fire up any interceptors - to say nothing of their potential effectiveness. Only one need get through to seriously fuck up the planet you're defending.

More limiting would be building such a weapon in the first place, powering it up, and keeping it free from molestation by defending forces (who's only chance is to take it out before it becomes 'fully operational' to use the term). Since it's a lot easier to go down than up a gravity well, I'd say the strategic advantage is anyone who has the high ground.

[frigidmagi]

Are you talking about shooting at relativistic projectiles?

I thought we were discussing lower tech hard sci fi?

[LadyTevar]

I think the opening of the nBSG showed the best way for it to happen.

Nukes from orbit, airbursting above the major cities. Not that hard to aim at a major city, they don't move much and are large targets.

[Destructionator XV]

I thought we were discussing lower tech hard sci fi?

Yes. Not perfectly hard (some allowances are possible, but nothing like breaking conservation of energy or hypermatter fuel bullshit, etc.), but relatively low tech.

I have this in mind for my own fictional universe, and want it to be at least somewhat believable, and most importantly, consistant.

Thus far, interceptors seem to be the best defense I've heard.

In my universe, I might just make it a political thing: a treaty forbids it. After all, it seems to me that hard sci-fi war wouldn't be as much ruled by the technology as it would be by agreed upon rules of war. But a treaty is only good if it can be enforced, so that is where the technology comes in.

[Stofsk]

I thought we were discussing lower tech hard sci fi?

Yes. Not perfectly hard (some allowances are possible, but nothing like breaking conservation of energy or hypermatter fuel bullshit, etc.), but relatively low tech.

Sorry, but I didn't read the words 'low tech' in the OP. Hard SF yes.

Thus far, interceptors seem to be the best defense I've heard.

Fallout shelters are another thing.

In my universe, I might just make it a political thing: a treaty forbids it. After all, it seems to me that hard sci-fi war wouldn't be as much ruled by the technology as it would be by agreed upon rules of war. But a treaty is only good if it can be enforced, so that is where the technology comes in.

Well, not quite. The notion of mass-retaliation is what enforces a treaty like that. Even the best interceptor system wouldn't be 100% effective, and in any mass-strike scenario some would get through. And counter-interception technology would arise - let's say if you develop it along precision-guided lines, the counter to that would be to create a multi-vector entry system.

However, an agreement that says "If you hit us, we'll hit you back tenfold" does more to deter an enemy's aggression than dubious interceptors. That doesn't mean you don't have interceptors, but that you rely on other means rather than put all your eggs in one basket.

[frigidmagi]

Sorry, but I didn't read the words 'low tech' in the OP. Hard SF yes.

Hard Sci Fi, to be frank is generally lower tech then the "soft" stuff. Unless you got a Hard Sci Fi that out does Star Trek in your back pocket there?

In my universe, I might just make it a political thing: a treaty forbids it. After all, it seems to me that hard sci-fi war wouldn't be as much ruled by the technology as it would be by agreed upon rules of war. But a treaty is only good if it can be enforced, so that is where the technology comes in.

You're gonna have to answer a couple questions for this to work.

Why does this treaty exist? The modern rules of war didn't spring out of no where for example. Did someone do this and the result was so awful humanity decided en mass to lock it up in a box and throw away the key?

Whose idea was it/Who enforces it? This is importent, if it's the idea and cherished rule of the biggest nastiest dogs on the block, people are less willing to break it then say... If it's the ruling of a committee in an international body that can threaten you with... Paperwork.

When does it apply? I'll give an example. It is an unoffical rule of warfare that you do not gas, nuke or virus bomb US troops. Why? Because the US has over 10,000 nuclear warheads and would love to find a place to store of them, long as they can be delivered airmail at high speed. Indeed during Gulf War I, and Gulf War II (Operation Iraqi Freedom, sucks balls as a name), the understood policy was that any assualt on US forces using NBC weapons on a wide scale was going to result in Baghdad becoming a nice glowing hole in the ground. Brutal? Yeah, but it works.

However gasing a nation the US doesn't really care for recieves no punishment, as Saddam used nerve gas against Iranian troops in the Iraq/Iran war without any real reaction of penalty.

Any questions?

[Cynical Cat]

You're gonna have to answer a couple questions for this to work.

Why does this treaty exist? The modern rules of war didn't spring out of no where for example. Did someone do this and the result was so awful humanity decided en mass to lock it up in a box and throw away the key?

Whose idea was it/Who enforces it? This is importent, if it's the idea and cherished rule of the biggest nastiest dogs on the block, people are less willing to break it then say... If it's the ruling of a committee in an international body that can threaten you with... Paperwork.

When does it apply?

The threat of retaliation in kind kept poison gas off the table for most of WW II (the British had plans to use it if the Germans managed a landing) and that was all the enforcement that was needed. The principles of deterence and retaliation in kind still apply with OB, but as frigid says, you need a sociological framework to hang it on. WWII and the Cold War had the threat of retaliation in kind for attacks against members/allies. Babylon 5 had a long history of various kinds of interstellar contact, not all of it nice, and the appropriate framework limiting what was allowable in acceptable, limited wars (which the Centauri and the Mimbari both violated at times when they believed themselves powerful enough to get away with it).

[Stofsk]

Sorry, but I didn't read the words 'low tech' in the OP. Hard SF yes.

Hard Sci Fi, to be frank is generally lower tech then the "soft" stuff. Unless you got a Hard Sci Fi that out does Star Trek in your back pocket there?

Hard SF isn't so cut and dry. There are a lot of far-out stuff that don't blatantly go against physics unlike soft SF conventions such as gravitics or FTL, for example. That doesn't mean they're low tech in comparison. Antimatter is pretty far-out, and you don't need soft SF to suggest an antimatter bomb wouldn't bust a planet.

Apparently Alastair Reynolds has written some Hard SF stories that has a lot of far-out stuff.

[Narsil]

A good way to bombard a planet is not to directly 'attack' it; just hit it with enough chemical weapons and pollutants to make the atmosphere pretty much unlivable.

[Destructionator XV]

A good way to bombard a planet is not to directly 'attack' it; just hit it with enough chemical weapons and pollutants to make the atmosphere pretty much unlivable.

Big problem there is the planet is now useless to you too.

EDIT: And that many chemical weapons would be extremely expensive. A planet is a really big place.

[Narsil]

It depends what you want the planet for.

If you're after resources like metals and oil the like, you're not going to really bother with keeping it inhabitable. And you only really need enough chemical weapons to destroy society to the point of 'No Real Resistance'.

[Destructionator XV]

But now it becomes far more expensive to extract the oil or whatever from the planet. If you destroy the local population, you need to train your own people and bring them in to do the work, whereas if they were still alive, you could possibly stick in a puppet government or something and profit off their work.

With the area being uninhabitable, any workers you bring in now need to wear life support gear and buildings need to be built with this in mind. It just becomes obscenely expensive.

And if you are going after natural resources, would you really hit a populated planet anyway? The solar system is a big place, or the galaxy even bigger if you have FTL, so why not just mine something empty? If it is oil you need, it might be harder to find, but still, odds are you can find a planet without human life and just use it. And without FTL and you are in one solar system, knocking out the Earth of the bunch is just a bad idea. You don't have more.

Moreover, once the gloves come off, all hell is liable to break loose. Little guys fear you, and when they are afraid is when they resort to something like terrorism. Big guys see you as savage, and you could next be facing an international coalition to put a stop to you. And with the gloves already being off, the other powers would be less reserved to use their WMDs on you too.

[Kreshna Aryaguna Nurzaman]

But now it becomes far more expensive to extract the oil or whatever from the planet. If you destroy the local population, you need to train your own people and bring them in to do the work,

Um, today's oil companies also brought their trained engineers and technicians to the drilling site instead of relying on the local indigenous people.

[frigidmagi]

Because in alot of cases, that was cheaper option.

[Graey]

If it absolutely had to happen, there'd be a way. One possibilty is good old missles, just like we have today, except with powerful attittude thrusters and the same manner of heat sheilding that is used for space shuttle re-entry.

[Batman]

If it absolutely had to happen, there'd be a way. One possibilty is good old missles, just like we have today, except with powerful attittude thrusters and the same manner of heat sheilding that is used for space shuttle re-entry.

Except at has been pointed out in this thread before (which has BTW been dormant for two months before your post) you can basically achieve the same by throwing really big rocks at the planet.