Attacking Darius:

cthia wrote:Everyone is making one of the most common thus frequent mistakes on the forum. Time and time again it is reproduced. But, when attacking Darius this mistake could be fatal. Very well will be.

We know it won't.

What the game-changer will be, we don't know. But something will make that attack possible.

Possibilities:

• the GA develops effective, even if limited, spider detection capability;
• the attack happens before the MAN can build sufficient spider-driven defences;
• the attacking force is so disproportionately large (RMN, IAN, RHN, GSN, SLN) that it offsets the stealth advantages;
• a fifth column inside the Onion thwarts plans to defend, defecting with plans and/or sabotaging defences.

Or maybe there will be no attack on Darius and a revolution inside the Onion deposes the Detweilers.

Attacking Darius is taking on a completely different paradigm in tactical and strategic planning. You cannot treat the MAN as if it is a traditional navy. Because it isn't. Everything will be different. You cannot judge a MAN by his clothing, or his attire by your closet. Case in point, let's address a major wound ...

No one is treating them as a conventional navy here.

Gentlemen, you have just hypered into a system that turns its weaknesses into strengths. This system has formulated its tactics and strategy around its own technology and not around the wedges of enemies. When you hyper into the Darius System you cannot expect the tactical situation to resemble anything outside of that system.

That's a vague statement. Tell us concretely what it means in terms which assets are used, where they are placed, and how they're used.

And, you cannot fly rings around emplacements that you cannot see.

A fort with no bubblewall is extremely vulnerable against a lucky shot. See the post above for why it has to be close to the planet it's defending. And like Jonathan and munroburton have said, an asset that moves like a ship, fights like a ship, and quacks like a ship is a ship, not a fort.

And you don't have to see the attacker to keep evading. Make long, zig-zagging courses, spiralling down the gravity well towards the planet, so the defender forces which you don't see get all garbled up.

Plus! This system uses the enemies strengths against them. This system turns the enemy's higher accel into a liability. When warships are pulling five hundred gravities they can't instantly alter their bearing like a dogfighter. And an enemy that has totally infested its system with invisible system defense pods and invisible forts and Spiders will have those weapons emplaced at very specific strategic positions to ward off the much quicker but far more clumsier flies flying blind. Have you ever played the game of Fox & Geese? Making the right move - strategic and methodical - traps the fox every time.

No, but a ship pulling 500 gravities can change its vector much more quickly than one pulling 150 that was trying to shadow it can. The problem with the smaller acceleration is that the defenders MUST take the inner position, which means they must be at a much more limited volume of space than the attackers.

The lower acceleration is a weakness. It cannot be turned into a strength.

I would imagine that while Forts may enjoy specific positions of mutual support, Spiders also crawl to specific predefined locations at the first sign of invasion. Spiders and Forts don't need to be quicker, just smarter. As long as those faster ships don't outrun the calculated engagement range of the Spiders plus their graser torps. That is what I meant by ...

Agreed. They must fight smart to compensate for the weakness of their acceleration. The capital ships may use their stealth to their advantage too.

And don't forget that whatever GR drones, LACs, or other expendable or semi-expendable assets you have scouting ahead of your fleet will have wedges (and every one of them is higher acceleration than any spider ship or torpedo).

If the MALign did somehow fill that approach area with vast numbers of ships and weapons if they manage to avoid detection then sooner or later one of those recon asset's wedges will physically touch a spider ship or weapon; which will be pretty spectacular.



Though, hell, if the GA fleet hypers in and can't see any defenders start by lobbing an Apollo strike at the planetary orbit. You should be able to optically see stations against the planet, but launch some missiles even if you can't. Apollo is accurate and reliable enough to be somewhat trusted near an inhabited planet and the incoming fire will give the MAlign navy a bit of a quandary.
* If they engage those missiles they'd be exposing some non-trivial amount of their hidden defenses (which will then be targeted with follow-up strikes (possibly forcing even more defenses to expose themselves)
* But if they don't engage they'll start losing their orbital infrastructure and yards which they need (longer term) to supply and maintain their fleet and defenses.

(And of course the inbound missile salvo also might run over and destroy, in passing, hidden spider ships or weapons that can't get out of their way)

The MA stealth system is really very good.

If you can't detect a fort until within a light second then the odds that you'll get anything close enough to detect it is small.

Those really hot reactors on the RMN recon drones are not easy to hide, and once you detect them it's fairly easy to kill them. IR seeking missiles are not exactly something that the HV is unable to build.

kzt wrote:The MA stealth system is really very good.

If you can't detect a fort until within a light second then the odds that you'll get anything close enough to detect it is small.

That's close enough for a missile to strike. And said missile can be launched from many light-minutes away, as Jonathan was suggesting.

And if the missile finds nothing? Well, fire a "warning shot across the bow" of the planet, sweeping if possible. It might hit something.

Another point is that the shipyards are not stealthed. Wherever they are in the system, they stick out like a sore thumb. The GA attacking force can lob missiles at them soon after translating from hyper. And like Jonathan said, the MAN must defend them, which will reveal the defence assets, which will be the target of the next salvo.

The drawback is that pieces of the destroyed shipyards may fall on the planet and cause mass destruction. You know, like Oyster Bay.

Jonathan_S wrote:And don't forget that whatever GR drones, LACs, or other expendable or semi-expendable assets you have scouting ahead of your fleet will have wedges (and every one of them is higher acceleration than any spider ship or torpedo).

I was thinking that the attacking fleet could adopt a spherical area (volume)-denial approach.

Energy weapons have a range of up to a million km. So let's create a shell of recon drones keeping pace with the fleet at R=1.5 million km (5 light-seconds) radius. The surface of that sphere is 4πR², or 28 trillion km². If Ghost Rider recon drone has sufficient probability of detection at r=100,000 km or less, its cross-section of detection is πr². To perform the packing, let's say it's a regular hexagon, so the area of responsibility for each drone is 3√3r² / 2. Dividing the area of the sphere by the area of each hexagon and ignoring the curvature of the sphere, we get that the number of drones N = 8πR² / 3√3r² = 8π√3(R/r)² / 9. Putting our numbers in the equation gives N = 1088.27 drones.

If the grand fleet came with just 250 SD(P)s, that's just 4.3 drones per SD(P), not including any drone launched by an escort vessel. In other words, that number of drones is believable.

At half the 1.5 million km radius, the fleet has wall-escort ships, consisting of CAs, CLs, DDs, and LACs. All those ships are equipped with FTL transceivers. Let's say for the sake of the argument that the coordination is done by the ship at the very centre of the arrangement. Since the detection occurs at 5 light-seconds from said ship, it'll receive the information in 5/62 = 0.08 s = 80 ms. The command to the nearest interceptor takes 40 ms to reach it. If the target hadn't moved, the graser beam firing at it would take at a minimum 2.5 s. That means the minimum possible interception time is 2.62 s. It's going to be a bit more than that because fire control is not instantaneous and the closest ship is not going to necessarily be at the minimum possible distance of 750,000 km. On the other hand, the target has moved into the sphere.

By how much? A Leonard Detweiler-class ship can maintain 250 gravities for short periods of time and 150 gravities indefinitely. Or, in other units, 0.0176 c/h sustained acceleration and 0.00049 c/min emergency acceleration. As calculated above, the entire engagement from hyperlimit to zero-zero with the planet is about 5 hours, so an LD could get up to 0.088 c in that time. Let's say it adds 250 gravities in the last 10 minutes, it'll have reached 0.093 c. That's the speed at which it crosses the 1.5 million km detection shell. If I round up the time for intercept to 3 seconds, this ship can move 83846 km in the direction it was travelling.

And in 3 seconds, it can only deflect its base vector by 11 km. So one graser shot may not suffice to hit it, much less kill it. But a few dozen might.

Moreover, since this ship is only moving at less than 28,000 km/s, it'll take 17.9 seconds from detection to its minimum energy weapons range. And it has to between engaging only with the chase grasers or turning broadside, which is a trade-off between the smallest profile presented to the oncoming grasers and the biggest.

So I conclude the chance of a lone LD penetrating this shell and reaching weapons range is minimal.

ThinksMarkedly wrote:Moreover, since this ship is only moving at less than 28,000 km/s, it'll take 17.9 seconds from detection to its minimum energy weapons range. And it has to between engaging only with the chase grasers or turning broadside, which is a trade-off between the smallest profile presented to the oncoming grasers and the biggest.

BTW, energy weapons range is just 250,000 km from the inner shell, which is counter-missile range. And the CMs can range 313,855 km in those 17.9 seconds at 200,000 gravities.

So I conclude the chance of a lone LD penetrating this shell and reaching weapons range is minimal.

Of course, that's not the strategy that the MAN would adopt. That's clearly suicide.

I'd expect them to send all the ships and the kitchen sink, so as to increase the number of detections and maximise the probability that some reach weapons range. Moreover, I'd expect them to deploy the torpedoes before detection. Now, I have no clue how many an LD can deploy... I'd expect them to pre-deploy patterns of them and tractor them behind the ship (because you can't limpet them on the hull!), but this may affect their acceleration too. So I'm going to make a wild guess and say that each LD can deploy 30 immediately before detection and each Shark can deploy 10. If the MAN defending forces consist of 3 8-ship LD squadrons and 6 8-ship Shark squadrons, that's a total of 24*30 + 48*10 = 1200 torpedoes inbound. Plus the 72 ships, that's 1272 contacts.

That's a much higher chance that some of them will reach energy weapons range.

Still, the GF would definitely target the ships first, of which there are only 72. If we assume all of them are wiped out before reaching energy weapons range but no torpedoes were, that leaves 1200 torpedoes. Earlier I said that I'd expect a 5:1 ratio of torpedo-to-ship to guarantee a kill, which should be enough for 240 SD(P)s. However, 5:1 was without the benefit of knowing the attack is coming, when and where from, coupled with a shot from much closer range, not 1 million km. The ships at the centre of the shell have had nearly 18 seconds of advance warning, during which they can fire swarms of Dazzlers and Dragon's Teeth in defensive mode. Plus, those ships can turn their wedges towards the incoming detection, though I expect that 18 seconds is not sufficient for a full turn in the worst case (but the attackers can't count on that case either).

So I don't see this attack with 24+48 ships working at all. It will kill some SD(P)s, but not sufficiently. Obviously, it would be better to have more ships attacking at once, from the same angle, so as to saturate the defences in any cone, but this is where the lower acceleration of the defenders hurts them: if their forces must be distributed around the system in order to react to an enemy emerging from any point, then they can't all arrive time-on-target because they can't choose the time in the first place.

So how many SD(P)s can a 24+48-ship attack like this kill? It's difficult to say and I guess that David will roll the dice on his random number generator plus use whatever Plot Hammer he needs to get to a result. It could be as low as 12 or as high as the 120 for a 10:1 kill ratio. If it's an average of 62.5, then the MAN needs 4 such attacks to neutralise the capital ships. And wipes out the MAN but leaves all of the GF battlecruisers. Moreover, this assumes the GF showed up with only 250 SD(P)s; remember that Honor had 500+ under her command when she paid a visit to Sol.

I'll go further and say that the MAN having 4 * 24 Leonard Detweiler-class ships anywhere before 1930 pushing the boundary of belief, worse if we talk about 120 ships. I've posted before on this topic, so I won't rehash it here.

And finally, to make a bad day even worse for the MAN, all this assumed the defending task-force managed to get to 0.093c on a straight vector towards the centre of the invaders' formation, which would take them 5 hours @ 150G and 10 minutes @ 250G to achieve. Remember a few posts above when I said the minimum time could be as low as 228 minutes, though the low ends of the range imply more predictable courses. On the other hand, the invading force can pull a fast one and take longer to arrive, by changing vectors, going backwards, and overall making a zig-zag & spiral course. The defenders cannot afford to be left out of position and zooming past at 0.075c outside engagement range, so they have to wait. Which in turn means they will not have anywhere near 5 hours of constant acceleration in a straight line. I wouldn't give them more than 1 hour even if I were feeling the most generous possible, which brings their top speed to one fifth of that 0.093c and thus multiplies by 5 the time it will take them to cross the detection shell to their weapons' range. That's a whopping 85 seconds, during which time the invaders are shooting at them and all they can do is shoot at the escorts.

If the GA showed up with this formation, I think the MAN would need to whittle down the escorts at the 750,000 km mark before sending in the capital ships. I'd do that using torpedoes, which reach 1,000,000 km mark from those ships and still be about a light-second away from the Ghost Rider recon drones.

Firing from a million km away against an evading target is by no means a guaranteed kill. So let's say it takes 2 torpedoes per target, on average. Let's say the GF brought 40 CLACs to the party. That's 3840 LACs if they were all Minotaur-class CLACs, or 4960 if they were all Covington-class.

Either way, we're talking 8000-10000 torpedoes reaching engagement range. Since they accelerate very slowly, there's a good chance that some may zip past the invaders, so I'd double that in number of launches.

Can the MAN produce 17500 torpedoes before the GF arrives? Each torpedo costs probably about the same as a LAC.

ThinksMarkedly wrote:BTW, energy weapons range is just 250,000 km from the inner shell, which is counter-missile range. And the CMs can range 313,855 km in those 17.9 seconds at 200,000 gravities.

I'm not quite sure what you're trying to say, but I'm seeing confusion about various weapon ranges - so here are two relevant quotes from On Basilisk Station. (Though IIRC energy range against a target protected by sidewalls snuck up to 500,000 km at some point in the series)

[with] "no sidewalls to interdict, effective laser range was right on a million kilometers"

"Sidewalls could be penetrated, particularly by missiles fitted with penetration aids, but it took a powerful energy weapon at very short range (relatively speaking) to pierce them with any effect, and that limited beams to a range of no more than four hundred thousand kilometers."

Oh and for completeness -- Havenite CMs seem to still have about a 1.5 million km range, while the latest RMN/GSN/IAN CMs, the Mk31s, have a 3.5 million km range -- so in all cases much further than energy range.

Trying to score energy hits against alerted / evading targets from a million km away is very far from a guaranteed kill; I'd put it more like a low probability hope of hitting.
You'd have to be firing from one of the relatively limited bearings from which no sidewall (or buckler) was interposed and still guess exactly where the ship would be 3.3 seconds from firing. Even minor changes in its heading or roll might interpose a sidewall (or wedge) and at that range even a LACs sidewall should be able to shrug off SD grade energy fire.

Trying to score impeller missile hits from that range is probably fruitless. You're so close that even at their full power the missiles would be sitting ducks for the even higher accel CMs - but they're no so close that they'll crash into laserhead (or contact nuke) range before the targets can react.

And trying to score hits with graser torps from that close a range, while probably your best best, still seems dicey. That's much closer than the MAlign can detect a spider drive's start-up energy spike; and so there's a non trivial risk that the GL's launch would be detected allowing CMs to be launched in that direction and the general area swept with energy weapons fire. But even if undetected, that's so close that unless you were lucky to be in just the right spot the GL would have trouble closing to an optimal attack point. It would likely actually be better to launch it further back, where it's drive start-up isn't going to get spotted and where it's got time to maneuver itself so into the vulnerable forward arc of the oncoming targets. (Without risking putting your spider ship there at close range; where it would likely lack the acceleration or the base velocity to remain out of the oncoming formation's detection radius)

Jonathan_S wrote:

ThinksMarkedly wrote:BTW, energy weapons range is just 250,000 km from the inner shell, which is counter-missile range. And the CMs can range 313,855 km in those 17.9 seconds at 200,000 gravities.

I'm not quite sure what you're trying to say, but I'm seeing confusion about various weapon ranges - so here are two relevant quotes from On Basilisk Station. (Though IIRC energy range against a target protected by sidewalls snuck up to 500,000 km at some point in the series)

[with] "no sidewalls to interdict, effective laser range was right on a million kilometers"

"Sidewalls could be penetrated, particularly by missiles fitted with penetration aids, but it took a powerful energy weapon at very short range (relatively speaking) to pierce them with any effect, and that limited beams to a range of no more than four hundred thousand kilometers."

Thanks for the datum. Indeed, I increased that range to 1 million km, giving the MAlign an advantage because we know they have a long-lasting graser beam. If they made a breakthrough in endurance and this weapon is basically a big reactor to power the graser, I think it's acceptable to say it could punch through a sidewall at a million km. Of course, if it's 800,000 km or 600,000 km, that makes it much easier for the invaders.

However, the million km does apply to firing on the spider ships, since they have no sidewalls.

Oh and for completeness -- Havenite CMs seem to still have about a 1.5 million km range, while the latest RMN/GSN/IAN CMs, the Mk31s, have a 3.5 million km range -- so in all cases much further than energy range.

Problem here is not range, but time. You can only fire at a target at 1.5 million km if you it's going to be there when you launch. In this scenario, the defenders aren't detected until they reach that 1.5 million km shell and 750,000 km from the nearest ship that can launch CMs.

Trying to score energy hits against alerted / evading targets from a million km away is very far from a guaranteed kill; I'd put it more like a low probability hope of hitting.
You'd have to be firing from one of the relatively limited bearings from which no sidewall (or buckler) was interposed and still guess exactly where the ship would be 3.3 seconds from firing. Even minor changes in its heading or roll might interpose a sidewall (or wedge) and at that range even a LACs sidewall should be able to shrug off SD grade energy fire.

Indeed and this goes both ways. I"m going to keep giving them 1 million km range on either direction: the MAN has much more powerful grasers, but they have no sidewall so GA grasers work at the same distance too. Both sides are evading, so both sides have difficulty in predicting where the other ship will be.

But the GA has three advantages here: first, they have FTL sensors with FTL comm that have (in this scenario) locked on the attackers, so they know where their targets were 3.3 seconds before the shot. The MAN has FTL sensors too, but all they can see is the wedge, not the ship inside the wedge. Therefore, they have double the round-trip time. Second, the GA ships are protected by said wedge and sidewall, so there are aspects that no shot can go through and some that, even if it does, may be attenuated sufficiently to negate a kill. The MAN ships have no such protection, so all aspects are available for the shot. Third, the GA ships have anywhere between 3.5x and 5x more acceleration. Given that they also have double the time to evade, that means they can change position up to 20x more than the MAN ships.

BTW, one thing I've wondered and never seen an answer for: can ships evade at full acceleration in any direction? Or can they only do that in directions parallel to their longitudinal axis? Or something in-between?

Trying to score impeller missile hits from that range is probably fruitless. You're so close that even at their full power the missiles would be sitting ducks for the even higher accel CMs - but they're no so close that they'll crash into laserhead (or contact nuke) range before the targets can react.

Firing guns from knife-fighting range.

And trying to score hits with graser torps from that close a range, while probably your best best, still seems dicey. That's much closer than the MAlign can detect a spider drive's start-up energy spike; and so there's a non trivial risk that the GL's launch would be detected allowing CMs to be launched in that direction and the general area swept with energy weapons fire. But even if undetected, that's so close that unless you were lucky to be in just the right spot the GL would have trouble closing to an optimal attack point. It would likely actually be better to launch it further back, where it's drive start-up isn't going to get spotted and where it's got time to maneuver itself so into the vulnerable forward arc of the oncoming targets. (Without risking putting your spider ship there at close range; where it would likely lack the acceleration or the base velocity to remain out of the oncoming formation's detection radius)

The startup sequence wouldn't be an issue, since we're assuming that the instant they cross the 1.5 million km shell populated by recon drones, they're going to be detected any way. That's why I proposed that the MAN ships would be towing the torpedoes behind them and activate them right before detection.

Firing GTs without the ships was the second scenario I made, but we're also assuming those have lower acceleration than the ships, since they have less area to mount spider tractors on. That in turn means they have much smaller terminal velocity going through the detection shell, which in turn means the time they can be engaged is proportionately greater.

Ah, I suppose we could have a hybrid scenario: the capital ships go out to meet the invaders, but then drop their accelerations to match that of the torpedoes a couple million km out. If those ships can carry internally more torpedoes than they can tow, they could have several times more torpedoes going through the detection shell than the 1200 I speculated.

ThinksMarkedly wrote:
The drawback is that pieces of the destroyed shipyards may fall on the planet and cause mass destruction. You know, like Oyster Bay.

If you are engaging from light minutes the real issue is that your missiles will strike the planet directly.

The MAN spent a lot of effort avoiding producing a geometry that intersected the planets because MDMs are very stupid and tend to lock onto things that they shouldn't.