Realistic Space War

[tater]

In space over penetration is not really an issue. Have the warhead detonate at some distance and it ceases to be a long-rod penetrator, and becomes a cloud of smaller particles with the same KE.

[FungusForge]

Asteroid chucking would be a whole lot of effort and risk, just to ruin a planet for a good long while.  Ship-on-ship combat would also be a lot of risk and effort, but would allow the sparing of infrastructure and populace of the planet. Missile Pong, as I call it, would be low-risk, high reward, and wouldn't totally ruin the planet, but infrastructure and populace would still be wrecked.
Missile Pong trumps all, as has been determined by many an argument before this. Using a fleet of ships would only be useful in a situation where the planet, its inhabitants, or its infrastructure is desired relatively intact. 

And yes, all this still stands for a moon-to-moon conflict.

 

E:

That said, ship-on-ship combat would either be trading railgun slugs, missiles, or lasers. Missiles would hold the range game, where lasers would be the mid range. Railgun and other kinetics would dominate close quarters.

Edited April 21, 2016 by FungusForge

[p1t1o]

7 hours ago, radonek said:

You forgot to factor in two significant facts. First, Earth's mighty industry have to spend significant energy to get their stuff out of the well. Second, Mars is "up" in Suns gravity well, which pretty much gives Martians kinetic weapon for free.

So, one quite reasonable Martian War scenario is that martians quickly deploy few small guided Rods, use them to destroy Earthlings precious spaceports and arrive to dictate their terms.

For exactly this reasons any such war would more likely be waged between Moon loyalists and Belters. Like I said, planets are overrated.
 

That doesn't sit quite right somehow. Mars is "up" only if the finish line is escaping from the Sun's SOI - in terms of who has it easiest launching kinetic weapons at each other, a projectile needs the same amount of dV to get from a Mars altitude to an Earth one, Mars can't just "drop" stuff on us, it has to be de-orbited "down" from Mars, most of the kinetic energy of the projectile (unless boosted spectacularly)  will come from falling into the target planets gravity well. A rock falling to periapsis at Earth will have a similar rock/planet speed difference as a rock flying up to apoapsis at Mars, just that the one headed towards Earth "hits Earth" but the one headed towards Mars "gets hit by Mars". And both fall a significant distance into a planetary gravity well.

Mars has a shallower gravity well, but it also has a far thinner atmospheric shield.

Most of that is up for debate admittedly, I dont have the maths to back it up

I'm sure there will be significant differences, but I don't think either planet has much of an advantage or disadvantage based on their orbital height above the Sun.

Ooh but here's a thought - if we are talking space rocks, I don't see any reason why the projectiles would come from the originators home planet, unless we started chipping bits off our moons, but then we have a gravity well to boost them out of. I think both sides would have a presence in the asteroid belts and the threat would be originating from there. Mars has a disadvantage here as they would have less warning of an incoming projectile, though the converse is also true, that they would be closer to their military operations.

[radonek]

1 hour ago, p1t1o said:

Mars can't just "drop" stuff on us, it has to be de-orbited "down" from Mars, most of the kinetic energy of the projectile (unless boosted spectacularly)  will come from falling into the target planets gravity well.

My bad, my Moho expeditions apparently left me with wrong ideas. But event if it comes from our dear dirtball's stronger  gravity, I still hold that martians are at advantage. According to handy graph at wikipedia martians will give their rod nudge of 2.3km/s to send it from orbital assembly on its way, then somehow forget to do a capture burn and arrive at LEO with 3.9km/s to spare. Earthlings, being in reversed situation are clearly at disadvantage. Surface-to-surface difference is 6.7km/s in martians favor, minus earths denser atmosphere which I have no idea how to factor in. But I have a hunch that Rods are being a rods to minimize that.

 

2 hours ago, p1t1o said:

Ooh but here's a thought - if we are talking space rocks, I don't see any reason why the projectiles would come from the originators home planet, unless we started chipping bits off our moons, but then we have a gravity well to boost them out of. I think both sides would have a presence in the asteroid belts and the threat would be originating from there.

I was talking about some variant of Rods, because those are afaik most readily available weapons. You forge a metal rod, add some simple guidance, mount it atop a rocket booster and fire it on its merry way. Moving rocks takes a lot of time (barring some miraculous new propulsion method), which IMO would turn whole affair into a Belt war, with both sidespushing on suitable rocks and interrupting similiar operations of other side. Or, if it comes to worst, deflecting incoming projectiles in reversed scenario. A big rock that is nearly on a collision course could become quite a battlefield. And Earth would have more suitable rocks to choose from, but they would also be easier to deflect.

3 hours ago, p1t1o said:

Mars has a disadvantage here as they would have less warning of an incoming projectile

If you see collision on current orbit, its already too late anyway. Big rocks have to be pushed a long time to change their orbit - one way or other. Rock-throwing war is to be waged at scale of decades or even centuries.  (Unless you happen to have some Apophis at hand anyway.) Its quite possible for one side to "win" and then find some forgotten rock a century later that was easy to deflect then, but impossible to move now.

Also, another thing is that plantes closer to Sun have more solar energy at their disposal… but I don't think that will be a factor until Mercurian Independence War :-)

[FungusForge]

@radonekis hitting the nail on the head here. Sending metal rods at the enemy to hit with the force of nukes would be the most efficient method of defeating the enemy. Flat out. If destruction of the enemy is desired, there's no need to bother grabbing rocks from the belt when you can just hurl depleted uranium sticks at them. And those sticks can be built with stealth tech too.

Asteroid bombing is arduous, constantly vulnerable to attack, and just plain overkill. I mean, if we asteroid bombed the other guy, that planet is going to be cooked, and its crust would probably be molten. With RftG you can hit the most strategic targets and cripple the enemy without totally obliterating them. Less total energy in your attacks would also drastically reduce any residual damage the planet itself may face.

[tater]

Any SF universe where ships have loads of dv invariably results in a threat of very powerful KE weapons dominating strategic thought. That doesn't mean that "conventional" conflict is impossible, but it all happens under the umbrella of a MAD type system. 

[Bill Phil]

2 hours ago, tater said:

Any SF universe where ships have loads of dv invariably results in a threat of very powerful KE weapons dominating strategic thought. That doesn't mean that "conventional" conflict is impossible, but it all happens under the umbrella of a MAD type system. 

Unless the propulsion system is friggin massive. Then you'd have to deploy your KE weapons and then veer off course.

Edited April 22, 2016 by Bill Phil
Beer=\= veer

[SSgt Baloo]

6 minutes ago, Bill Phil said:

Unless the propulsion system is friggin massive. Otherwise you'd have to deploy your KE weapons and then beer off course.

"You heard the man. After we dump the missiles, we're getting beer!"

Edited April 22, 2016 by SSgt Baloo

[WinkAllKerb'']

you need a sponsor to do so:

try "nike"

Edited April 22, 2016 by WinkAllKerb''
...

[sojourner]

4 hours ago, FungusForge said:

@radonekis hitting the nail on the head here.

He did?  Boy, I'm glad I brought it up.

[tater]

4 hours ago, Bill Phil said:

Unless the propulsion system is friggin massive. Then you'd have to deploy your KE weapons and then veer off course.

I'm not aiming them at ships. You attack me, and I aim them at worlds. Any SF universe where some guy in a cheap, "tramp" ship can burn his blowtorch drive forever just made every cheap ship a planet-killer.

[p1t1o]

15 hours ago, radonek said:

If you see collision on current orbit, its already too late anyway. 

One still might appreciate more time to launch a counter-strike, or time to get people into bunkers? Or at least more time to scream silently into the void...

[FungusForge]

What if the goal isn't the total annhilation of the enemy? What if there are important assets planetside or you want to use the planet itself? What if you're stepping in to free the civilian populace? IMHO I think asteroid and kinetic missile bombardments wouldn't quite work for those jobs, and would mostly defeat the purpose.

[Bill Phil]

7 hours ago, tater said:

I'm not aiming them at ships. You attack me, and I aim them at worlds. Any SF universe where some guy in a cheap, "tramp" ship can burn his blowtorch drive forever just made every cheap ship a planet-killer.

And what if 95% of the population, industry, and the like aren't on worlds?

[sojourner]

2 hours ago, Bill Phil said:

And what if 95% of the population, industry, and the like aren't on worlds?

A space colony is more fragile than a planet.

[FungusForge]

42 minutes ago, sojourner said:

A space colony is more fragile than a planet.

More fragile, sure, but unlike planets, a fleet of ships or even an assisted station can move out of the way. They can just keep doing evasive maneuvers once they realize they are under fire. Heck, they could be hiding behind planet or moons, completely blocking shots. In fact, a fleet a ships and stations could be stealthier then a planet-based city, meaning you can't actually shoot them until you have confirmed their location, which would mean getting your own ships up close.

Opposite to striking at a planet-based enemy, long-range bombardments would actually drag the conflict out longer than needed I think.

[sojourner]

A large space colony wouldn't be able to move fast enough to dodge a "rod from god" approaching at relativistic velocities. The detection time would be far too short.

[tater]

58 minutes ago, FungusForge said:

More fragile, sure, but unlike planets, a fleet of ships or even an assisted station can move out of the way. They can just keep doing evasive maneuvers once they realize they are under fire. Heck, they could be hiding behind planet or moons, completely blocking shots. In fact, a fleet a ships and stations could be stealthier then a planet-based city, meaning you can't actually shoot them until you have confirmed their location, which would mean getting your own ships up close.

Opposite to striking at a planet-based enemy, long-range bombardments would actually drag the conflict out longer than needed I think.

They cannot possibly move fast enough. To have even a chance of a miss vs a single projectile the station needs to offset itself randomly by a cross-sectional radius. Say it's an O'Neil colony cylinder, and the radius is 2 km. That means it needs to be able to (best case, end-on to attack) move 2km unpredictably between detection, and impact. That only allows for a chance the weapon will not hit, not a guarantee. If dv is cheap/free because magic drives, then the weapon has the same. At some range, the weapon can disperse shrapnel one way or another. Then evasion become even more difficult.

[FungusForge]

Why go for the overkill crown when it'd be cheaper, and saner, to try and recapture the station? I mean, if I was the general or admiral or whatever, and my military was strong to even possess a relativistic cannon in the first place, I'd just go in with a cruiser and pop their life support. Once they're all suffocated popsicles, I'd send guys in to clean out the station, repair it, and keep using it. No real point in using a multi-million dollar slug to overkill an equally expensive station when I can send a three-thousand dollar slug to kill all the problematic guys in a very efficient manner that even nets me an (almost) free station to use for my own purposes.

 

Besides, if I was the leader of the guys going against the dudes with relativistic guns that they are happy using to atomize me, then I sure as all heck won't stay still long enough to meet one of those slugs. It takes light more than 3 minutes to reach Mars on a good day. And, a relativistic gun isn't something you can hide, and a relativistic shot that's self-propelled would be too expensive (resource and currency) to use on anything other than a planet, barring magical drives, which goes beyond realism.

Edited April 22, 2016 by FungusForge

[tater]

This is the entire point of my original post in this thread. Every single aspect of the scenario in question needs to be stated as the "given," including the relevant politics, goals of combatants, etc.

You could argue that everyone has an Age of Sail sensibility, and they board with cutlasses, too.

[FungusForge]

4 minutes ago, tater said:

This is the entire point of my original post in this thread. Every single aspect of the scenario in question needs to be stated as the "given," including the relevant politics, goals of combatants, etc.

Well, I figure "realistic" as the OP asks, means assuming that the technology present is based in realism. So, science fiction magic drives that have Dv in the vigintillions of m/s are out. We also should assume that both sides are not super-evil Empires hell-bent on destruction of anything that disagrees with them.

Fact is every time I've seen one of these discussions on the web, everyone goes for this solution:

Spoiler

Everyone loves the pure overkill solution and always assumes that the only way a conflict can end. To say the least I have yet to see that in real life. The closest thing is Hiroshima and Nagasaki, but it was only those those cities when we could've turned all the major Japanese cities into radioactive wastelands and basically plunged the country into the stone age. If Mars got their knickers in a twist and decided to revolt, why would we turn the planet into a uninhabitable molten rock with an asteroid when we just send Rods at their major colonies. Why vaporize a revolting station with the ultimate in overkill when you can go in and swiftly kill the occupants without scattering the station across the cosmos.

Yes, wars end when Side A gets a big enough stick to knock out Side B, but assuming the only way to win is dropping a massive tree on his head is ridiculous.

[tater]

Then realistic means at most anti-sat weapons in earth orbit, as nothing else is remotely plausible in the distant, foreseeable future.

[FungusForge]

My definition of realistic:

28 minutes ago, FungusForge said:

So, science fiction magic drives that have Dv in the vigintillions of m/s are out. We also should assume that both sides are not super-evil Empires hell-bent on destruction of anything that disagrees with them.

I guess it could use the addendum of no magic shields or yet-to-be-built weapons like plasma cannons and the such. We can stretch the bounds of what we have, of course, otherwise a space war isn't even possible. At the least can we should keep in mind that nuclear option doesn't mean first choice, but last resort.

[Bill Phil]

4 hours ago, sojourner said:

A space colony is more fragile than a planet.

But a space colony doesn't have to shave off every unneeded gram of mass. Armor plating and defense systems guarentee it'll be fine. If the projectile is going fast enough, it'll just go straight through the colony. Leaving a few holes. But that's not a problem either. There's so much air that it would take years for all of it to leak out. The only issue, then, is the number of deaths and injuries. Along with costs of destruction.

Space colonies don't have to be fragile. If anything, they're stronger than your average city, what with tonnes of steel per square meter to block radiation.

2 hours ago, tater said:

They cannot possibly move fast enough. To have even a chance of a miss vs a single projectile the station needs to offset itself randomly by a cross-sectional radius. Say it's an O'Neil colony cylinder, and the radius is 2 km. That means it needs to be able to (best case, end-on to attack) move 2km unpredictably between detection, and impact. That only allows for a chance the weapon will not hit, not a guarantee. If dv is cheap/free because magic drives, then the weapon has the same. At some range, the weapon can disperse shrapnel one way or another. Then evasion become even more difficult.

Depends on distance. If they know something's coming, and they have an Orion drive, then they can dodge quite a bit.

[wumpus]

2 hours ago, FungusForge said:

Well, I figure "realistic" as the OP asks, means assuming that the technology present is based in realism. So, science fiction magic drives that have Dv in the vigintillions of m/s are out. We also should assume that both sides are not super-evil Empires hell-bent on destruction of anything that disagrees with them.

Fact is every time I've seen one of these discussions on the web, everyone goes for this solution:

You do realize that both the USA and Russia built the capacity to destroy each other and then bounce the rubble multiple times?  And that large chunks of the forum lived through that?  And that whats left of those space war systems can still basically end life as we know it (mostly through civilization collapse after the major cities get nuked and related ecological catastrophe).

Once you start building such a massive part of your gross national product toward weapons systems, there isn't much incentive to build one that can lose.  So you build one that will at least not lose, that at least one "super-evil Empire" began building one that could destroy the other in hopes that it would incur only "acceptable losses".

We have exactly one type of spacewar that was planned, prepared for, and ready to happen if one of two men pressed a single button (actually I have no idea of the means the USSR had to launch a nuclear war.  I strongly suspect that nobody was willing to follow the American system after their experience with Stalin).  We have exactly one type of space war that could have happened *within minutes* of pressing those two buttons, and it lasted for *decades*.

Pretending human nature is different than historical example is pretty foolish.  Human leaders love to beat the drums of war.  Their followers fall over each other to give them more power, and the cycle keeps going until wars happen.  Then everybody wonders how it got started and pretends not to be involved.