How the hell do ground invasions work in Star Wars?

[Sea Skimmer]

Ground to space fire is more expensive than a ground protecting shield?

But it's quite possible that with the ease of sending ships to space in Star Wars, it may have come about that they decided that ground-to-space weaponry was largely unnecessary because if your enemy controls the space around you anyway, you're probably screwed in the long run and ground-to-space weapons only make sense in a limited tactical envelope, such as covering escapes to space like at Hoth.

After a certain low point fixed ground weapons would simply have no possible advantage compared to simply keeping mobile warships inside of your shield. Thus they cannot be defeated by an enemy fleet prior to breaching the shield, and the enemy fleet cannot mass against a weak spot in the fixed ground defenses. These ships could simply be regular warships, or they could be dedicated atmospheric only craft built for the job.

Worth remembering the primary point of shore batteries has always been to deter a naval attack, rather then defeating it outright, something rather hard to do since the enemy will just decline to blunder into range. If you raise the attack price enough the enemy is far less likely to ever try in the first place. Mounting enough weapons to stop a full scale invasion outright will probably never make fiscal sense.

Aerosols' a smart idea. I bet we'll have that IRL for laser-weapons. Didn't they use weirdass sprinkler systems - or at least theorize that - as counter for laser-designated strikes?

Aerosols are what smoke is...it works awesome and you can put silica into it to massively increase its laser resistance if you want. Of course this will also mean the smoke cloud scatters still blinding laser light EVERYWHERE...

The Sweds deployed water foggers full scale to protect shore batteries from laser guided attacks which is what I think you are thinking of. They also tested this on the CV90.

The problem is this idea works by randomly reflecting the laser back onto the ground around the a target, so it's erratic and the maximum miss distance will be low unless the bomb completely looses lock and goes dumb. That was in fact a likely result with a 1980s first and second generation laser seekers, the later ones are much less likely to fall for this due to major improvements against the backscatter/multipath problem in general which had always made LGB use touchy. The bomb now has some serious image processing in its brain and can still try to figure out the center of the laser scatter. Since then a lot more advanced laser decoys that actually use mast mounted lasers themselves have been tested. Most people some content with smoke for the role.

If you want to defeat a laser weapon attack then smoke is generally a lot better then a reasonable water fog because you'll get way more protection per weight of stuff blown in the air. The Sweds didn't want to use smoke because it would mask their own visual observation devices, and it would actually mark the turret locations for non guided Soviet air attacks. Meanwhile since these were fixed 75mm turrets around 200mm thick by the seashore inducing only small misses was okay, nothing but a direct hit would hurt them, and the water supply was unlimited.

But its not like a giant anti orbital gun site couldn't have a 500,000 gallon tank of fog oil under it, in relative terms that would probably barely cost anything. Hell you could have giant piles of space coal you burned on demand, about anything is plausible in a universe with death stars.

Since like even the Ottomans used bombards for centuries!

That's a reality, its on thing not to have a trained up mass army, it's another to go and throw all your weapons away! The later is just insane and leads to obviously stupid problems like Europe somehow being threatened by Russia on the GDP of Italy. Naboo was weak, but it was a BS sector capital that's probably like Utah territory was in 1862. Even then the 50 or so fighters they had isn't exactly a joke either, pretty much was a defense against anything short of a organized invasion.

In space where hyper drive means an enemy army can appear from anywhere in the galaxy without warning even in time of peace people would keep serious ass firepower around. They can probably make ammo with a shelf life of thousands of years, modern guns would already last like that if kept dry with the return springs taken out. Its not like real life where at the least, a major armored invasion can only come directly across a national border, or to a port which provides strategic warning.

[The Romulan Republic]

So, what would be the minimum defences necessary to secure a world against attack by, oh, a squadron of capital ships (such as the force deployed at Hoth by the Empire)? Which I'm guessing is the most that would typically be allocated to a single world unless it was an incredibly high-value/well-defended target like Coruscant.

I'm thinking, minimum, theatre shields over all major population/industrial centres and key military facilities, with at least one (preferably multiple) ion canon or turbo laser battery per shield (enough to provide full coverage of planetary orbit, as previously discussed in this thread), plus several squadrons of torpedo-armed star fighters, and sufficient ground troops to secure the shield generators/ground batteries from sabotage.

[Abacus]

So, what would be the minimum defences necessary to secure a world against attack by, oh, a squadron of capital ships (such as the force deployed at Hoth by the Empire)? Which I'm guessing is the most that would typically be allocated to a single world unless it was an incredibly high-value/well-defended target like Coruscant.

I'm thinking, minimum, theatre shields over all major population/industrial centres and key military facilities, with at least one (preferably multiple) ion canon or turbo laser battery per shield (enough to provide full coverage of planetary orbit, as previously discussed in this thread), plus several squadrons of torpedo-armed star fighters, and sufficient ground troops to secure the shield generators/ground batteries from sabotage.

Well, firstly, let's be fair and remind everyone that Death Squadron was not a normal deployment. They were a special task force put together by Darth Vader for the sole purpose of hunting down the Rebel leadership and Luke Skywalker.

I would think that a typical Imperial assault line, which, according to older (technically non-cannon) sources would be:

...three to six ships depending upon the outfit of ships present; heavy cruisers and other large ships were generally fewer in number in attack lines, whereas light cruisers and frigates were were in greater number.

The purpose of the attack line was to engage enemy starships of equivalent size, or, when in the presence of a Star Destroyer or other, larger capital ship, to engage the enemy within range of the Star Destroyer, making sure the Star Destroyer is out of effective range of enemy ships, thus allowing the Star Destroyer to concentrate on destroying any enemy starship rather than focus on defense.

So it would appear that smaller vessels, like the VicStars and maybe older Venators, Dreadnoughts, etc, would make up an attack line -- with smaller frigates and corvettes accompanying in escort formations. If we're going by more canon sources, then let's look at the most numerous examples -- those given by the Grand Army of the Republic in Star Wars The Clone Wars tv series. We constantly see the Jedi generals making attacks on planets with 3-6 Venators, with smaller ships occasionally in attendance (the extra escorts are naturally not in the show, since that means more animating and more money).

Minimum defense against that kind of attack? A simple planetary shield is enough as a defense. Combine it with orbital platforms and other ground based weaponry, and it could be something far more effective.

If you other have theatre shields then you're leaving the planet itself open to attack. Heavy turbolaser barrages can melt a planet's surface, causing all sorts of unnaturally-created earthquakes and tidal shifts. Nothing quite as dramatic as the low-powered attack as seen made by the Death Star in Rogue One, but a similar, if slower, effect.

That again is dependent upon the objectives of the attackers. If they only want to set an example, then orbital bombardment is fine. If they wish to capture a planet? Then your description of theatre shields becomes far more effective. That effectively makes it a ground war; one which, unless the attacking forces have technological or strategic advantages, the defenders will have the advantage.

[Lord Revan]

Thing to remember is that attacker will generally have a secure logistical base (since it won't be on the planet being invaded), while the defender won't (since all their logistical capacity will be on the planet being invaded) giving the attacker an inherent strategic advantage at least when we view each invasion in isolation. Since if we won't view them isolation the question comes more complex, since the defenders can have allies that can threaten the logistical base of the attackers or provide off-world aid to the defenders.

since if the attackers won't have such a numbers or techlogical advantage that invasion is over in at most in few days, but probably in hours. Logistics are gonna play a much greater role then the initial numbers. Since if once side can replace their losses in troops and material without a real challenge while the other has to deal with constant attacks on their training centres, armories, supply centres and so forth it's not hard to see which side has the advantage.

[The Romulan Republic]

Well, firstly, let's be fair and remind everyone that Death Squadron was not a normal deployment. They were a special task force put together by Darth Vader for the sole purpose of hunting down the Rebel leadership and Luke Skywalker.

Granted, but my point is more that it was a strong force committed to a high priority mission against a well-defended (relatively speaking) planet, which means that its probably pretty close to a high-end for what you would normally expect to be devoted to a planetary assault.

I would think that a typical Imperial assault line, which, according to older (technically non-cannon) sources would be:

...three to six ships depending upon the outfit of ships present; heavy cruisers and other large ships were generally fewer in number in attack lines, whereas light cruisers and frigates were were in greater number.

The purpose of the attack line was to engage enemy starships of equivalent size, or, when in the presence of a Star Destroyer or other, larger capital ship, to engage the enemy within range of the Star Destroyer, making sure the Star Destroyer is out of effective range of enemy ships, thus allowing the Star Destroyer to concentrate on destroying any enemy starship rather than focus on defense.

So it would appear that smaller vessels, like the VicStars and maybe older Venators, Dreadnoughts, etc, would make up an attack line -- with smaller frigates and corvettes accompanying in escort formations. If we're going by more canon sources, then let's look at the most numerous examples -- those given by the Grand Army of the Republic in Star Wars The Clone Wars tv series. We constantly see the Jedi generals making attacks on planets with 3-6 Venators, with smaller ships occasionally in attendance (the extra escorts are naturally not in the show, since that means more animating and more money).

Well, as you say, that's non-canon now.

I would think, then, that the best guide to planetary assault forces would be what we see during the film and TV depictions of the Clone Wars, and Galactic Civil War.

Minimum defense against that kind of attack? A simple planetary shield is enough as a defense. Combine it with orbital platforms and other ground based weaponry, and it could be something far more effective.

A planetary shield might stop an attack (provided the shield generators are secured against attack by infiltrators or turncoats on the ground). But without ground batteries and/or ships, it forces the defenders into a purely defensive role, with no ability to hit back. Which means that barring outside aid, the attackers can choose the time and place of battle, and take their time to concentrate their forces, while maintaining an effective blockade.

If you other have theatre shields then you're leaving the planet itself open to attack. Heavy turbolaser barrages can melt a planet's surface, causing all sorts of unnaturally-created earthquakes and tidal shifts. Nothing quite as dramatic as the low-powered attack as seen made by the Death Star in Rogue One, but a similar, if slower, effect.

Well, theatre shields are not a perfect defence, but perhaps all some worlds can afford, and enough to seriously impede an attacker unless they're prepared to go to genocidal extremes.

That again is dependent upon the objectives of the attackers. If they only want to set an example, then orbital bombardment is fine. If they wish to capture a planet? Then your description of theatre shields becomes far more effective. That effectively makes it a ground war; one which, unless the attacking forces have technological or strategic advantages, the defenders will have the advantage.

Pretty much.

[Galvatron]

Aerosols are what smoke is...it works awesome and you can put silica into it to massively increase its laser resistance if you want. Of course this will also mean the smoke cloud scatters still blinding laser light EVERYWHERE...

For what it's worth, this is how the anti-laser aerosols were portrayed in the novel (which also depicts a planetary invasion force of Republic gunships versus a defending force of Separatist interceptors):

“Alliance weapons should have us in target lock by now,” Salvo said as the gunship continued to descend.

Other assault ships were also punching through the cloud cover, only to be greeted by flocks of incoming missiles. Struck by direct hits, two, four, then five craft were blown apart, flaming fuselages and mangled troopers plummeting into the churning scarlet waves of Murkhana Bay. From the nose of one gunship flew a bang-out capsule that carried the pilot and co-pilot to within meters of the water before it was ripped open by a resolute heat seeker.

In one of the fifty-odd gunships that were racing down the well, three other Jedi were going into battle, Master Saras Loorne among them. Stretching out with the Force, Shryne found them, faint echoes confirming that all three were still alive.

He clamped his right hand on one of the slide door’s view slots as the pilots threw their unwieldy charge into a hard bank, narrowly evading a pair of hailfire missiles. Gunners ensconced in the gunship’s armature-mounted turrets opened up with blasters as flights of Mankvim Interceptors swarmed up to engage the Republic force. The anti-laser aerosols scattered the blaster beams, but dozens of the Separatist craft succumbed to missiles spewed from the gunships’ top-mounted mass-drive launchers.

“High Command should have granted our request to bombard from orbit,” Salvo said in an amplified voice.

“The idea is to take the city, Commander, not vaporize it,” Shryne said loudly. Murkhana had already been granted weeks to surrender, but the Republic ultimatum had expired. “Palpatine’s policy for winning the hearts and minds of Separatist populations might not make good military sense, but it makes good political sense.”

As you can see, the aerosols required both sides to rely on missiles.

[Simon_Jester]

I wonder if there are planetary superlasers that act similar to the Death Star's in that they can converge to a point high enough above the planet's surface and then be redirected towards a target that would normally be out of their line of sight.

I imagine such a weapon would be tremendously powerful as well.

Converging beam weapons are seen multiple times throughout Star Wars, but I don't think we've ever seen one that can fire "off-axis." The LAAT's converging-beam weapons are mounted in ball turrets, for instance, and I'm pretty sure that's because the weapon can't fire off-axis. So I doubt that such a planetary superlaser is viable using Star Wars technology.

Something that did occur to me earlier. Even in the old EU, planetary shields were commonplace but majo ground to space weaponry was rare. Given that a shielded planet can be besieged/bloackaded quite easily if they can't hurt ships in orbit, is it reasonable to think that the Empire allowed planet shields but severely restricted planetary defence weapons? TO make it easier to bottle up and bloackade rebellious planets without having to expose ships to serious risks?

Very much reasonable.

Every centralized government, whether it's good or evil, tends to restrict the power of local and provincial authorities to fortify their own home bases. This is a big part of how Europe transitioned from decentralized feudal power to centralized governments after the Middle Ages. The landed, military aristocracy's old castles were now obsolete. So it was possible for the government to enforce its own laws on their territory, without having everything come to a screeching halt every time some random baron decided to rebel, forcing the crown to spend a year or two besieging his castle.

Honestly, I suspect that the old Republic would have limited planetary defense artillery too. Insofar as they stopped doing it, that probably resulted in the rise of the CIS, with swarms of independently fortified systems that the Republic couldn't police, and who would have found Republic laws annoying and burdensome.

Ground to space fire is more expensive than a ground protecting shield?

Maybe, but there's no real evidence in Star Wars as a whole that an energy weapon is more expensive than a shield capable of stopping that energy weapon.

Indeed, on the small scale the opposite seems to be true- most fighting vehicles are armed with heavy weapons, but not with heavy shields. The only people we've seen making use of defensive force fields on a large scale in ground combat are the Gungans, whose military technology is just too freakish for words.

Now, things may scale differently on the level of planets and starships, but even there, we don't see examples of weapons being expensive while shield generators are cheap. So I'd be surprised if planetary shields cost much less than planetary defense artillery.

But it's quite possible that with the ease of sending ships to space in Star Wars, it may have come about that they decided that ground-to-space weaponry was largely unnecessary because if your enemy controls the space around you anyway, you're probably screwed in the long run and ground-to-space weapons only make sense in a limited tactical envelope, such as covering escapes to space like at Hoth.

Under the Republic (back when the Republic was functional-ish) it usually would have made more sense for a law-abiding planet that was threatened to hide under its shields and scream for help from the Republic fleet, yeah. And I think a lot of planets simply didn't revisit that decision as the Republic began to collapse and the Empire rose. "Alderaan is a peaceful planet, we have no weapons."

After a certain low point fixed ground weapons would simply have no possible advantage compared to simply keeping mobile warships inside of your shield. Thus they cannot be defeated by an enemy fleet prior to breaching the shield, and the enemy fleet cannot mass against a weak spot in the fixed ground defenses. These ships could simply be regular warships, or they could be dedicated atmospheric only craft built for the job.

Worth remembering the primary point of shore batteries has always been to deter a naval attack, rather then defeating it outright, something rather hard to do since the enemy will just decline to blunder into range. If you raise the attack price enough the enemy is far less likely to ever try in the first place. Mounting enough weapons to stop a full scale invasion outright will probably never make fiscal sense.

That's a fair point. On the other hand, it's a reasonable aspiration to at least have enough firepower to deter a naval attack all around your planet. Given how the firing arcs for a planet work, that requires a fairly large number of individual weapon mounts.

Having mobile ships fly around under cover of your defensive shield might work about as well, but you'd have a couple of problems.

One is response time. If the ships are based on one side of the planet, and for reasons of firing arc you want them on the other side, then either they have to go hypersonic in the atmosphere for long periods, or they're going to take quite a while to arrive. They can't go exoatmospheric without passing through the shield, at which point they no longer benefit from its protection and have to be space-capable. That in turn increases the size and defensive requirements of the mobile platforms, until you're effectively buying your own star destroyers.

Which brings up the other problem. See, having your own ships fly around under your shield and potentially go exoatmospheric to deal with the attackers would be fine for an independent planet that had that kind of money. But in the context of planets normally being vassals of some major interstellar power, it won't fly. Fixed defenses are fixed; you can't use them to go commerce raiding. A mobile hover-battleship that can win duels with raiding frigates and can plausibly be refitted with a hyperdrive is a different matter.

[Lord Revan]

Aerosols are what smoke is...it works awesome and you can put silica into it to massively increase its laser resistance if you want. Of course this will also mean the smoke cloud scatters still blinding laser light EVERYWHERE...

For what it's worth, this is how the anti-laser aerosols were portrayed in the novel (which also depicts a planetary invasion force of Republic gunships versus a defending force of Separatist interceptors):

“Alliance weapons should have us in target lock by now,” Salvo said as the gunship continued to descend.

Other assault ships were also punching through the cloud cover, only to be greeted by flocks of incoming missiles. Struck by direct hits, two, four, then five craft were blown apart, flaming fuselages and mangled troopers plummeting into the churning scarlet waves of Murkhana Bay. From the nose of one gunship flew a bang-out capsule that carried the pilot and co-pilot to within meters of the water before it was ripped open by a resolute heat seeker.

In one of the fifty-odd gunships that were racing down the well, three other Jedi were going into battle, Master Saras Loorne among them. Stretching out with the Force, Shryne found them, faint echoes confirming that all three were still alive.

He clamped his right hand on one of the slide door’s view slots as the pilots threw their unwieldy charge into a hard bank, narrowly evading a pair of hailfire missiles. Gunners ensconced in the gunship’s armature-mounted turrets opened up with blasters as flights of Mankvim Interceptors swarmed up to engage the Republic force. The anti-laser aerosols scattered the blaster beams, but dozens of the Separatist craft succumbed to missiles spewed from the gunships’ top-mounted mass-drive launchers.

“High Command should have granted our request to bombard from orbit,” Salvo said in an amplified voice.

“The idea is to take the city, Commander, not vaporize it,” Shryne said loudly. Murkhana had already been granted weeks to surrender, but the Republic ultimatum had expired. “Palpatine’s policy for winning the hearts and minds of Separatist populations might not make good military sense, but it makes good political sense.”

As you can see, the aerosols required both sides to rely on missiles.

that section from the novel (that's from the post ROTS vader one right?) also explains why (well gives one reason anyway) "blast them from orbit" isn't the silver bullet seem to think it will would be, any population that's been bombed to stone age is gonna be royally pissed off assuming they survive of course meaning that system will be rebellious even if it seems openly loyal, but limiting collateral damage to what's unavoidble makes it easier to win the hearts and minds of the opposition even if tactically it might not seem like the best option. So it's actually good military sense too from strategic PoV even if it's not best tactical sense.

Another reason while orbital bombardment isn't a silver bullet is that as the attacks aren't done in isolation the galactic neighbourghs of those systems bombarded might take a disliking to that so instead of 1 rebellious system you got several and there's a domino effect to it also, since at some point those protesting systems are gonna start eating up your potential logistical capasity (when enough systems previously loyal start to think "hmm maybe this empire isn't that good after all if it randomly depopulates planets").

[Galvatron]

Another reason while orbital bombardment isn't a silver bullet is that as the attacks aren't done in isolation the galactic neighbourghs of those systems bombarded might take a disliking to that so instead of 1 rebellious system you got several and there's a domino effect to it also, since at some point those protesting systems are gonna start eating up your potential logistical capasity (when enough systems previously loyal start to think "hmm maybe this empire isn't that good after all if it randomly depopulates planets").

I think that was the whole idea behind "The more you tighten your grip, Tarkin, the more star systems will slip through your fingers."

As I've stated before, the Empire really shit the bed, politically, when they both disbanded the Senate and destroyed Alderaan. I can imagine that even worlds loyal to the Empire were dismayed at having lost their political representation and then threatened with total destruction by Tarkin's new superweapon...until it was suddenly destroyed by the rebels.

If those worlds weren't suitably defended against Imperial subjugation before, I can imagine that they took steps to remedy that in the wake of the Battle of Yavin. They needn't even openly declare support for the Alliance, just that they were taking precautions against any hostile forces that may threaten them.

[Elheru Aran]

If those worlds weren't suitably defended against Imperial subjugation before, I can imagine that they took steps to remedy that in the wake of the Battle of Yavin.

I wonder if that's one inspiration for Tagge's build-up of Super Star Destroyers post-ANH in the new comic series? For the cost of a Death Star, build several smaller but still massive ships that can be split between several systems in order to sit on potentially rebellious movements?

[The Romulan Republic]

Another reason while orbital bombardment isn't a silver bullet is that as the attacks aren't done in isolation the galactic neighbourghs of those systems bombarded might take a disliking to that so instead of 1 rebellious system you got several and there's a domino effect to it also, since at some point those protesting systems are gonna start eating up your potential logistical capasity (when enough systems previously loyal start to think "hmm maybe this empire isn't that good after all if it randomly depopulates planets").

I think that was the whole idea behind "The more you tighten your grip, Tarkin, the more star systems will slip through your fingers."

As I've stated before, the Empire really shit the bed, politically, when they both disbanded the Senate and destroyed Alderaan. I can imagine that even worlds loyal to the Empire were dismayed at having lost their political representation and then threatened with total destruction by Tarkin's new superweapon...until it was suddenly destroyed by the rebels.

If those worlds weren't suitably defended against Imperial subjugation before, I can imagine that they took steps to remedy that in the wake of the Battle of Yavin. They needn't even openly declare support for the Alliance, just that they were taking precautions against any hostile forces that may threaten them.

Yup. They were planning, by the looks of things, to pretty much rely on the Tarkin Doctrine, and the dissolution of the Senate was predicated on having the Death Star to effectively crush any dissent.

But the Tarkin Doctrine is a horribly limited strategy, which only works if the populace believes that you have the will and means to inflict overwhelming retaliation on any foe. And when the Death Star went up right after Alderan, they lost that guarantee of instant, massive retaliation against any system with a planetary shield. And by their prior actions, they'd sacrificed any ability credibility and good will in the political arena.

[Galvatron]

If those worlds weren't suitably defended against Imperial subjugation before, I can imagine that they took steps to remedy that in the wake of the Battle of Yavin.

I wonder if that's one inspiration for Tagge's build-up of Super Star Destroyers post-ANH in the new comic series? For the cost of a Death Star, build several smaller but still massive ships that can be split between several systems in order to sit on potentially rebellious movements?

Right after his promotion to grand general, Tagge said to Vader, "The starfleet is a sea. It is endless, cannot be beaten and given enough time turns even the strongest rocks to sand...our larger plans cannot be based around any individual asset. Not a Death Star. Not you, Vader. Such assets are best used, if you pardon the phrase, as a force multiplier."

So, yeah, it sounds like he was an old-fashioned military officer who preferred large fleets and protracted sieges to instakill battlestations.

[The Romulan Republic]

If those worlds weren't suitably defended against Imperial subjugation before, I can imagine that they took steps to remedy that in the wake of the Battle of Yavin.

I wonder if that's one inspiration for Tagge's build-up of Super Star Destroyers post-ANH in the new comic series? For the cost of a Death Star, build several smaller but still massive ships that can be split between several systems in order to sit on potentially rebellious movements?

Right after his promotion to grand general, Tagge said to Vader, "The starfleet is a sea. It is endless, cannot be beaten and given enough time turns even the strongest rocks to sand...our larger plans cannot be based around any individual asset. Not a Death Star. Not you, Vader. Such assets are best used, if you pardon the phrase, as a force multiplier."

So, yeah, it sounds like he was an old-fashioned military officer who preferred large fleets and protracted sieges to instakill battlestations.

Why does Tagge seem like the only top Imperial officer (besides Thrawn, maybe) who had his head on straight?

[fractalsponge1]

Theater shields are limited to forcing an enemy to fight on the ground if they want to take the planet intact. It doesn't help with threats of wrecking the place and everyone on it absent a surrender since the attacking fleet can just BDZ around the edge of the shield, or since presumably the theater shield would be less powerful than a planetary one, simply pound through it.

Shielded planets/continents in general are also going to still be vulnerable to massive direct attacks on the shield, because there's still momentum transfer. How able is a shield to transfer momentum of a petaton-exaton/s bombardment away without wrecking the planet around the generator foundations?

[Lord Revan]

If those worlds weren't suitably defended against Imperial subjugation before, I can imagine that they took steps to remedy that in the wake of the Battle of Yavin.

I wonder if that's one inspiration for Tagge's build-up of Super Star Destroyers post-ANH in the new comic series? For the cost of a Death Star, build several smaller but still massive ships that can be split between several systems in order to sit on potentially rebellious movements?

Right after his promotion to grand general, Tagge said to Vader, "The starfleet is a sea. It is endless, cannot be beaten and given enough time turns even the strongest rocks to sand...our larger plans cannot be based around any individual asset. Not a Death Star. Not you, Vader. Such assets are best used, if you pardon the phrase, as a force multiplier."

So, yeah, it sounds like he was an old-fashioned military officer who preferred large fleets and protracted sieges to instakill battlestations.

In Tagge's defense, large instakill battlestation or other individual assets repesent a single point of failure, so it's not a smart strategy to rely too heavily on those.

[Galvatron]

Why does Tagge seem like the only top Imperial officer (besides Thrawn, maybe) who had his head on straight?

Which leads me to wonder where the hell Thrawn was when Tagge got promoted. Did he not survive into the OT timeframe? Did he get sent to the Unknown Regions like his Legends counterpart? What about the other twelve grand admirals? Do they even exist in the new EU or could Thrawn be the only one? For that matter, what about the other grand moffs?

Shielded planets/continents in general are also going to still be vulnerable to massive direct attacks on the shield, because there's still momentum transfer. How able is a shield to transfer momentum of a petaton-exaton/s bombardment away without wrecking the planet around the generator foundations?

Good question for the calc-minded. Are you designing anything new based on the discussions in this thread?

In Tagge's defense, large instakill battlestation or other individual assets repesent a single point of failure, so it's not a smart strategy to rely too heavily on those.

True. Maybe the Empire always intended to create more than one Death Star for that very reason.

[Lord Revan]

Theater shields are limited to forcing an enemy to fight on the ground if they want to take the planet intact. It doesn't help with threats of wrecking the place and everyone on it absent a surrender since the attacking fleet can just BDZ around the edge of the shield, or since presumably the theater shield would be less powerful than a planetary one, simply pound through it.

Shielded planets/continents in general are also going to still be vulnerable to massive direct attacks on the shield, because there's still momentum transfer. How able is a shield to transfer momentum of a petaton-exaton/s bombardment away without wrecking the planet around the generator foundations?

the problem "just BDZings around the shield" is that you pretty much abandon that planet as a logistical asset, a living planet isn't a like an RTS zone where all that matters is the enemy units. indiscriminate devestation is only useful if you have absolutely no use for the planet and everyone else hates the target planet so much that there's no backlash from bombarding the planet.

terror bombardment has very limited strategic usefullness and 0 tactical usefulness. Wars of extermination are very rare and there's no reason belive that The Galactic Empire (or any other signifigant power for that matter) would want to wage such on their own terroritory.

That's one the things I hated about the Vong the absolute xenophobia to point that they massively waste assets just to kill things they didn't need to.

[Galvatron]

Yeah, turning a planet like Corellia into another Malachor would probably do the Empire little good aside from scaring the shit out of the rest of the galaxy. However, even doing that would probably just strengthen support for the rebellion.

[Sea Skimmer]

Converging beam weapons are seen multiple times throughout Star Wars, but I don't think we've ever seen one that can fire "off-axis." The LAAT's converging-beam weapons are mounted in ball turrets, for instance, and I'm pretty sure that's because the weapon can't fire off-axis. So I doubt that such a planetary superlaser is viable using Star Wars technology.

With the scale of stuff the universe builds as routine a moving dish up to at least several hundred meters should be no problem at all, probably kilometer scale is no actual engineering problem depending on how fast you want it to point. Expensive, but you would figure even a 300m scale weapon, which is much larger then ISD scale turrets, would just start to blast all enemy heavy ships out of action. They certainly aren't going to bother to duel with it, they'd just bring up some kind of siege weapon in reply. Anything bigger would only make sense if it can counterfire against some sort of known siege weapon threat.

The advantage of the converging beam weapons in canon seems to be they make much longer bolts then normal turbolasers; so that might matter for injecting raw energy to blow up planets, or making a solid beam of anti infantry power, but it may have no practical point for a anti ship gun trying to penetrate heavily armored and shielded ships. We can't know with existing canon.

'Can blow up this big of asteroid' considerations also come into play. You don't need one hit kills, so some kind of relationship between the the cratering and vaporizing effects would come into play on however the hell that's going to work. The death star type weapon might become favorable if you were worried about someone dropping your own moon on you. Imagine the Death Star itself just functioning as a tugboat for that. Maybe not quick, but once that orbit is spiraling down you have one hell of a problem.

Such levels of fortification as this though probably could not make sense anywhere except the galactic capital or similar total city planet where you just don't want to accept any possible means of it's destruction. Even then that would predicate on your own fleets being strategically weaker.

Honestly, I suspect that the old Republic would have limited planetary defense artillery too. Insofar as they stopped doing it, that probably resulted in the rise of the CIS, with swarms of independently fortified systems that the Republic couldn't police, and who would have found Republic laws annoying and burdensome.

They probably had artillery to defend whatever naval stations and fighter bases they did have, heavier guns might not be present. Something to recall also is that Star Wars technology loves to massively explode when damaged. So if you have some rich ultra defense core city planet with a shitload of money all the people who actually live on that planet are probably going to favor defense systems that operate above the shield, and won't massively explode beside their houses. Ultra rich areas are also likely to have extensive facilities within 1 star system, which is where a mobile defense force would really pay off.

Enormous numbers of multipurpose missiles become pretty logical at that point. Cross load them between platforms and all that. So you can stockpile them on planets, but then partly mobilize the stocks later if you can move over to the offensive and actually destroy the enemy fleet. If you don't destroy the enemy fleet the fortress planet has to keep building, since the enemy will certainly keep building. It's not like a 1500s siege where mud might render the enemy logistics impossible if you build an insane enough heap of dirt and corpses. Starships work and work so well they can work when held together with bullshit.

That's a fair point. On the other hand, it's a reasonable aspiration to at least have enough firepower to deter a naval attack all around your planet. Given how the firing arcs for a planet work, that requires a fairly large number of individual weapon mounts.

I'd agree if your going to do much, you need at least some counter bombardment type coverage around your entire planet, so the enemy can't just chip away at your shield endlessly with a converted gun scow firing one turbolaser out of a hatch and surrounded by TIE escort. That might not take that many sites if you can exploit (by which I mean partly demolish and level off, with explosions and PROGRESS) existing mountain ranges for better coverage. Also star wars tech can build flak towers 10km tall basically anywhere it pleases so to a certain point it just depends how built up this place already is.

But low altitude anti invasion fire would just be crazy with blasters and turbolasers, just like it'd be crazy in real life to plan to kill every single enemy paratrooper in his chute. You'd want that kind of defense heavily massed on key points, where it might actually work. If you want wide area coverage, that's what technology is for. Build anti everything missiles to lob over the horizon, build OGW, build supermassive electromagnetic artillery. Anything else and you better start drilling society like North Korea to man all those flak guns.

One is response time. If the ships are based on one side of the planet, and for reasons of firing arc you want them on the other side, then either they have to go hypersonic in the atmosphere for long periods, or they're going to take quite a while to arrive. They can't go exoatmospheric without passing through the shield, at which point they no longer benefit from its protection and have to be space-capable. That in turn increases the size and defensive requirements of the mobile platforms, until you're effectively buying your own star destroyers.

I'm assuming a shield can stand up to some bombardment. Shields almost always make sense in Wars, only TIE fighters seem to sometimes not have them, on assumes to give an absolute speed advantage over shielded fighters, but near everything down to some man sized droids has a shield. So obviously shields work pretty damn well compared to the penalty of having them exist and be powered. If your guns are primarily fixed the enemy faces a lower attack price if he actually wants to make an assault. So it depends on what you really expect to defend against I suppose. Since shields work at any given level of budget increase your going to want to make sure you've added even more shield.

Massive fortifications have never been cheap, they do in fact compete directly with naval power as a strategy. On a planet where you can't run away you might justify nearly anything, like 3000ft thick cut and keyed rock walls, but if you can do that stuff you can certainly afford destroyers and gunboats. These ships could also attack an invasion force, and retreat behind successive theater shields you might deploy under your planetary shield. Because seriously, it's not like anything makes us stop. 300ft deep anti walker ditches will solve our walker problem and we can build those 8,000ft deep subways too......but generally you only want to do stuff like if you've got no choice.

Which brings up the other problem. See, having your own ships fly around under your shield and potentially go exoatmospheric to deal with the attackers would be fine for an independent planet that had that kind of money. But in the context of planets normally being vassals of some major interstellar power, it won't fly. Fixed defenses are fixed; you can't use them to go commerce raiding. A mobile hover-battleship that can win duels with raiding frigates and can plausibly be refitted with a hyperdrive is a different matter.

I suppose, but conversely by flying these defenses cannot be captured by a riot mob on the street demanding social justice or similar liberal nonsense. That's the very reason why all those European gunpowder era star fortresses began going back and adding dedicated citadels. The government control of the citadel prevented a clean rebel takeover of the city, restoring the role of the Norman era castle keep. Security for fixed ground sites would get really involved really quick when you consider a civilian YT-1300 freighter bomb isn't even the high end of the terrorist threat spectrum.

My concern is situations where you have massed bombardment and then partial shield failure and an enemy invades. You can put up theater shields to continue coverage of other zones from orbital fire, but the enemy no longer has reason to risk his ships. All your fixed anti orbital guns won't fire another shot again, except maybe directly in their own defense against a ground attack. So how able and well is that going to work? Turbolasers only being direct fire is an issue, even if the horizon is far off. With mobile platforms meanwhile you have much more wide ranging ability to turn your guns on an invasion instead of awaiting defeat in detail by 10m caliber siege mortar attacks. The Empire I assure you commander, will not run out of ammunition.

[fractalsponge1]

It doesn't help with threats of wrecking the place and everyone on it absent a surrender

Um, see this part? What if an attacking force commander says "surrender or I'll turn the area around the shield edge into a lava lake and steam-cook everyone under it"? Political limitations are important, but that doesn't help a garrison or civilian population not hell-bent on suiciding for strategic astropolitical considerations. The Empire presumably would be taken on its word that it is willing to inflict massive casualties to crush opposition as a point of principle.

This demonstrates a key limit of partial shielding. The attacker might lose, but the defender cannot win. Not every continent will have a Luke Skywalker as an unwitting hostage.

[fractalsponge1]

Shielded planets/continents in general are also going to still be vulnerable to massive direct attacks on the shield, because there's still momentum transfer. How able is a shield to transfer momentum of a petaton-exaton/s bombardment away without wrecking the planet around the generator foundations?

Good question for the calc-minded. Are you designing anything new based on the discussions in this thread?

Certainly orbital/atmospheric defense platforms are moving up on the to-do list.

[Galvatron]

Are you designing anything new based on the discussions in this thread?

Certainly orbital/atmospheric defense platforms are moving up on the to-do list.

Any plans to do the TIE striker? Your LAAV/i and Zeta-class carryall would be excellent designs for use in a planetary invasion scene.

[Simon_Jester]

With the scale of stuff the universe builds as routine a moving dish up to at least several hundred meters should be no problem at all, probably kilometer scale is no actual engineering problem depending on how fast you want it to point.

Hm. Good idea. Should have thought of that.

'Can blow up this big of asteroid' considerations also come into play. You don't need one hit kills, so some kind of relationship between the the cratering and vaporizing effects would come into play on however the hell that's going to work. The death star type weapon might become favorable if you were worried about someone dropping your own moon on you. Imagine the Death Star itself just functioning as a tugboat for that. Maybe not quick, but once that orbit is spiraling down you have one hell of a problem.

Shooting it repeatedly with 'merely ordinary' heavy antiship weapons might do the job- you'd cause so much shattering that you might well knock the thing back into a stable orbit, and would tend to reduce the problem to one of large numbers of individually smaller fragments you could take on the planetary shields.

But you're not wrong to point out the issue.

Such levels of fortification as this though probably could not make sense anywhere except the galactic capital or similar total city planet where you just don't want to accept any possible means of it's destruction. Even then that would predicate on your own fleets being strategically weaker.

Or on not wanting to gamble on their eternal superiority. It's like building walls for your city in an ancient or medieval context. You hope your field army can keep them at bay, but it's so much better to have walls and not need them than to need walls and not have them!

Plus, hyperspace interdiction technology and the like is a thing in Star Wars, at least in the old EU and maybe in the new. It's not impossible to imagine a situation where some enemy could show up above your planet and somehow trap or prevent reinforcements from reaching you in time to prevent the planet from taking damage. Good planetary shields are the minimum needed to prevent that, and having some meaningful anticapital weapons for shooting back into space would be really helpful.

They probably had artillery to defend whatever naval stations and fighter bases they did have, heavier guns might not be present. Something to recall also is that Star Wars technology loves to massively explode when damaged. So if you have some rich ultra defense core city planet with a shitload of money all the people who actually live on that planet are probably going to favor defense systems that operate above the shield, and won't massively explode beside their houses. Ultra rich areas are also likely to have extensive facilities within 1 star system, which is where a mobile defense force would really pay off.

Hm. That's a good point.

Now I'm imagining designated island bases and stuff where the heavy weapons are installed, with an extra layer of shields that forms underground so that the entire island fortress can explode and burst up through the shield like a blowout panel if something goes wrong.

I'd agree if your going to do much, you need at least some counter bombardment type coverage around your entire planet, so the enemy can't just chip away at your shield endlessly with a converted gun scow firing one turbolaser out of a hatch and surrounded by TIE escort. That might not take that many sites if you can exploit (by which I mean partly demolish and level off, with explosions and PROGRESS) existing mountain ranges for better coverage. Also star wars tech can build flak towers 10km tall basically anywhere it pleases so to a certain point it just depends how built up this place already is.

Yeah, but you saw me do the math. No matter how tall your flak towers are, you don't really want to have to fire parallel to the horizon or at extremely shallow angles. So you do wind up needing at least 6-8 sites to cover the whole planet properly, and more would be highly desirable.

But low altitude anti invasion fire would just be crazy with blasters and turbolasers.

Agreed. The catch is that if you only have a single-digit number of installations spread across the entire planet providing surface-to-space firepower, the blind spots in your firing arcs are hundreds of kilometers high. That stretches the definition of "low altitude" pretty far.

Which brings up the other problem. See, having your own ships fly around under your shield and potentially go exoatmospheric to deal with the attackers would be fine for an independent planet that had that kind of money. But in the context of planets normally being vassals of some major interstellar power, it won't fly. Fixed defenses are fixed; you can't use them to go commerce raiding. A mobile hover-battleship that can win duels with raiding frigates and can plausibly be refitted with a hyperdrive is a different matter.

I suppose, but conversely by flying these defenses cannot be captured by a riot mob on the street demanding social justice or similar liberal nonsense. That's the very reason why all those European gunpowder era star fortresses began going back and adding dedicated citadels. The government control of the citadel prevented a clean rebel takeover of the city, restoring the role of the Norman era castle keep. Security for fixed ground sites would get really involved really quick when you consider a civilian YT-1300 freighter bomb isn't even the high end of the terrorist threat spectrum.

Hm. That's an interesting point, although there are a lot of good ways to manage the security.

Like having mounting the fortifications on islands hundreds of miles offshore or on top of remote mountains whose sides have been artificially steepened into 200-meter cliffs. Rioters aren't going to be able to get close unless they're flying. At which point you have light surface beam mounts to ionize and tractor anything that flies too close without a transponder code.

My concern is situations where you have massed bombardment and then partial shield failure and an enemy invades. You can put up theater shields to continue coverage of other zones from orbital fire, but the enemy no longer has reason to risk his ships. All your fixed anti orbital guns won't fire another shot again, except maybe directly in their own defense against a ground attack. So how able and well is that going to work? Turbolasers only being direct fire is an issue, even if the horizon is far off. With mobile platforms meanwhile you have much more wide ranging ability to turn your guns on an invasion instead of awaiting defeat in detail by 10m caliber siege mortar attacks. The Empire I assure you commander, will not run out of ammunition.

In that context the mobile platforms are very much useful, though the fixed platforms also remain useful by doing exactly what they did at Hoth: deterring the enemy from sending heavy starships in over the areas still under your control to provide direct orbital fire support, and preventing the attacker from establishing a close blockade. At that point, they are back to being deterrent weapons instead of trading fire with the attacking fleet, though.

Theater shields are limited to forcing an enemy to fight on the ground if they want to take the planet intact. It doesn't help with threats of wrecking the place and everyone on it absent a surrender since the attacking fleet can just BDZ around the edge of the shield, or since presumably the theater shield would be less powerful than a planetary one, simply pound through it.

Shielded planets/continents in general are also going to still be vulnerable to massive direct attacks on the shield, because there's still momentum transfer. How able is a shield to transfer momentum of a petaton-exaton/s bombardment away without wrecking the planet around the generator foundations?

If a super star destroyer's shield generators can absorb comparable fire without being wrenched off their mountings and blown out through the far side of the ship, and without the crew being cooked alive inside the hull, I'd expect planetary defense experts to be able to use the same system on a comparable or larger scale for planetary shields.

One trick that occurs to me is to mount the shield generator on top of a scaled-up tractor beam that exerts force on very large zones of rock (and mantle) underneath it. Set it up right, and when you shoot the generator the impact is transferred elastically to half a million cubic kilometers of molten rock. It'll cause earthquakes, but no localized catastrophe.

Planets should have more ability to absorb momentum transfer and waste heat than ships, not less. Presumably this problem has a solution, unless ships routinely wind up scooting across the sky at comically high accelerations with par-broiled crews when they take hits.

[Rhadamantus]

With the scale of stuff the universe builds as routine a moving dish up to at least several hundred meters should be no problem at all, probably kilometer scale is no actual engineering problem depending on how fast you want it to point.

Hm. Good idea. Should have thought of that.

I'd agree if your going to do much, you need at least some counter bombardment type coverage around your entire planet, so the enemy can't just chip away at your shield endlessly with a converted gun scow firing one turbolaser out of a hatch and surrounded by TIE escort. That might not take that many sites if you can exploit (by which I mean partly demolish and level off, with explosions and PROGRESS) existing mountain ranges for better coverage. Also star wars tech can build flak towers 10km tall basically anywhere it pleases so to a certain point it just depends how built up this place already is.

Yeah, but you saw me do the math. No matter how tall your flak towers are, you don't really want to have to fire parallel to the horizon or at extremely shallow angles. So you do wind up needing at least 6-8 sites to cover the whole planet properly, and more would be highly desirable.

How much would that cost, though? If your defenses cost as much as an ISD, then in the 25,000 ISD verse, most planets won't be able to afford them.

[Simon_Jester]

This is on the whole true. On the other hand:

1) Costs of fixed defenses can be amortized over very long periods. The First Galactic Bank might just float your planet a 100-year loan to build fortifications (that will remain useful for centuries, potentially). It probably won't float you a loan to buy a hyper-capable warship, because the question "and how will you make your investment pay for itself" is likely to lead to the answer "planning to commit a little piracy, eh?"

2) It may well be that the real logistical killer that caps the number of star destroyer-sized ships is NOT the cost of the hardware. For example:

2a) Given how much power Star Wars ships would need (if we use the high-end energy estimates from the old EU), and how much of that has to go into propulsion, using a mobile ship requires very high ongoing maintenance budgets. Fixed defenses are likely to require much less fuel, because they don't have to be brought up to full power very often. By contrast, starships, in order to be effective, will require fairly extensive live drills, and making effective use of starships to fully secure your space requires that you cruise around and take advantage of your mobility. Fuel budgets will be much higher for a starship than for fixed defenses of comparable firepower. There are valid counterarguments to this, but it's one possibility.

2b) I have heard it speculated that one of the main limits on the size of the Empire's forces is finding sufficiently reliable officers to command them all. Even if the economy of the galaxy permitted the fleet to be ten times larger, that might be actively counterproductive from Palpatine's point of view. A more numerous fleet means more potential defectors and dissidents. Having a larger number of ships also makes it more likely that certain ships will be permanently assigned to certain postings rather than being kept moving around... which in turn increases the risk that those ships will become more loyal to the locality they defend than to the Empire at large.

Just because the Empire is a military dictatorship, doesn't mean that unlimited expansion of the military is desirable for them. Think about the fate that faced Moammar Qaddafi during the Libyan Civil War: he had vast arsenals of tanks, planes, and heavy guns, but he could operate only a small fraction of that arsenal at any one time, due to limits on the supply of available fuel and loyal, trained personnel.