Optimal Missile Size

[Theokrat (OP)]

Let’s have an analytical look at the optimal size of missiles. It can be easily demonstrated that missile size is a trade-off between two things: The ability to get missiles through enemy anti-missile defences, on the one hand. And, on the other hand the ability to cause internal damage to enemy ships, rather than only damage to armour.

Missile defences can shoot down a given number of missiles, regardless of their size, so using a large number of small missiles mean that more missiles get through the enemy missile defences. Conversely, using larger missiles means their individual warheads are larger, and damage will be “clustered” more closely together, and reach deeper into enemy armour or ships, if the missiles hit.

The challenge is to determine the quantitative result of these effects. Obviously, the relative magnitude of the effects differs, depending on the likely target, so in fact there is no optimal missile. Regardless, this analysis might still provide some insights.

Some limitations to this analysis: I will ignore several things that would make my life to complicated on the basis that these are not too common for most players: Sensors on missiles, ECCM on missiles, and armoured missiles. Not in this analysis, sorry. [EDIT]Forgot to mention: Shields are not in either. Ignoring them is in favour of large missiles, as shields negate the effect of clustering, and damage-per-second beocmes more relevant[/Edit]

Also we are going to compare equal total missile size scenarios (e.g. two size-1 missiles versus one size-2 missile) on the basis that these result in equal industrial costs, in equal weight of missile launchers, and in equal magazine space requirements, so broadly they reflect the costs-constraints hat players are facing. This is in favour of large missiles, because small missiles have at least two advantages that are not reflected: Small missiles cost less in R&D, and small missiles can be launched more quickly in succession. We are ignoring the effect that this means enemy AMMs have a lot more to deal with at the same time, and that targets could potentially be killed more quickly by this.

The first effect – ability to overcome enemy anti-missile defences – is easy to assess. If we launch X missiles, and Y get intercepted, then X-Y get through. Increasing X (more missiles of smaller size) means more missiles hit the enemy, and a larger total amount of damage is dealt to enemy ships. This is overall quite easy to asses.




The graph is pretty obvious:  The smaller the missiles, the less they are relatively affected by PD. The 1 Damage/MSP assumption is just to scale the graph and is otherwise not important. If we only cared about the total damage dealt, and face some anti-missile defences , then we should only ever use the smallest possible missile sizes.

However, we care how this damage is distributed between enemy amour and internal hits. Large missiles have an advantage due to damage clustering, but exactly how large is this advantage? Well, to be honest the math is really yucki, so I decided to run a numerical computer simulation:

A simulation requires a target so I had a look around the ship-design section and thought what might be a “typical” ship in regards to the armour layout. I decided on a design 40 armour tiles wide, with 6 layers of armours. That’s about 10,000 t, with slightly more armour than I saw I most designs, on the basis that we might be slightly more interested in destroying heavily armed enemies. I have now let this ship be hit by a given number warheads with a given size and recorded how much damage was caused. And because there are statistical fluctuations I have done this 10,000 times for each set-up.


The graph shows the resulting probability distribution for internal hits, with a total of 144 WH, which is either delivered as 16 strength-9 hits, 36 strength-4 hits, or 144 strength-1 hits. You can see that the WH1-missiles bombardment causes an expected 4.6 points of internal damage, while larger warheads have a higher probability of causing more internal damage (and a low probability of causing smaller internal damage). Note that the “kinks” in the graphs are not due to the finite sample size. One can let the situation run many times over and these do not materially change. Rather, these kinks are due to the way that multiple hits that are close to each other result in damage. In other words they are a part of the “real” probability distribution and not a sign of statistical weakness.

So larger warheads are better, but we knew that from the beginning. However, we can of course run the simulation with other set-ups as well. So we can use both effects at the same time and make a plot similar to the first one, but not with the total caused damage, but with the expected internal damage, given the remaining number of missiles and their respective warheads. As a simplifying assumption, we will consider every missile that penetrates the missile-defences as a “hit”, i.e. we assume that our missiles have a 100% hit chance.




And now we are talking. You can see that when the enemy has no capacity to destroy our missiles (0 on the x-axis), larger missiles are certainly better, as they are expected to cause more internal damage. However you can see that the blue line falls of much quicker than the other lines. At around 4 destroyed missiles, strength-9 and strength-4 missiles cause the same amount of internal damage (i.e. through 36-4=32 strength-4 explosions, vs. 16-4=12 strength-9 explosions).

Of course by comparing the blue and the red graphs we can nicely identify in what areas what missile size is better. Of course it depends on the target, and the total of launched WHs, but it still might be a nice pointer.

And there is a very interesting aspect when observing the green strength-6 warhead line. 6 is not a square number (unlike 4 and 9), and therefore has a slightly different damage profile. You can immediately see how inefficient this is! Even without any enemy missile defences, the advantage over a strength-4 warhead is minimal, and this small advantage erodes away very quickly. More importantly, a strength-6 warhead design is never optimal – either strength-9 is better, or strength-4 is better. And strength-6 is not even a good all-rounder. Strength-4 is much better suited to deal a good amount of damage across the entire spectrum. Note that the fact that the strength-6 warhead is not optimal anywhere is not only because it lies between the larger and the smaller number, but only because it’s a non-square number. If we plot the same graph with only square numbers you can see that every square-numbered WH size is optimal somewhere. Initially, strength-16 is best, then strength-9, followed by strength-4, and finally strength-1.




So, if you take anything away from this its don’t use warheads that are not a square number. They are almost certainly worse than the closest a squared-numbered warhead.

[jseah]

How does this affect the calculation if we take into account PD hit chance as follows:
Assuming a 20% AMM hit chance against a standard 1WH per MSP, how would raising or lowering the WH per MSP change the scenario, at the various tech levels?

At WH4 tech, 0.25 MSP is warhead to get 1 WH per MSP.  At WH5, only 0.2 of the MSP is warhead. 
At increasing tech, less of the missile is WH and fuel and thus the proportional speed increase is less when you decrease warhead and likewise the proportional speed decrease for increasing warhead is also less. 

0.05 of an MSP is not that much difference in terms of speed.  At WH5, size 4 missile might do better with strength-5 warheads instead of 4 and eating the lower speed (and thus higher interception rate from enemy AMMs)


Also, any chance of releasing the source and binary of the program you wrote to do the simulations?  I certainly don't think you did ten thousand live fire trials in Aurora.  =)

[blue emu]

Excellent analysis, Theo. Size-4 looks like a good GP warhead, when facing unknown PD defenses and armor.

[Nathan_]

As tech gets better missiles should definitely get smaller. I typically design size 6s first, then 4s, then 1s for fighters/mines.

[sloanjh]

And now we are talking. You can see that when the enemy has no capacity to destroy our missiles (0 on the x-axis), larger missiles are certainly better, as they are expected to cause more internal damage.

You need to add "and has no ability to shoot back at us, and has no shields" to the caveats in this statement.  If you're under fire in the engagement, then RoF (which you've ignored) becomes critical and heavily weights the analysis in the direction of missiles with an RoF of 5s (or size-1, if you don't have the tech for a 5s RoF).  Similarly, if the enemy has big enough shields that they can significantly recharge between salvos, the RoF again becomes important.  I expect that if you presented your data in terms of time to destruction of the enemy (assuming destruction at a specific number of internal damage points) that these effects would be pronounced.

One thing I realized from a post in the other thread - I've been assuming that size-1 missiles (and I do mean size-1, not strength-1) are better than size-2 missiles, since they'll have a 2x faster RoF.  This isn't necessarily true for high reload techs, since reload times have a 5s floor.  The correct statement is that, for the sandblasting regime, you want to put the biggest warhead that fits (assuming good range/performance parameters) into 5s reload-time missile.  As jseah points out, especially at low tech, this means that you won't be able to squeeze in warheads that have perfect-square strengths.  A different way to say it is that missiles are quantized in terms of size, which means that comparing e.g. strength-4 to strength-5 warheads in the abstract is missing an important design parameter.  If you can squeeze a str-5 warhead into the same size missile at a cost of 5% in hit probability, you'll have a better design.

John

[TheDeadlyShoe]

I would like to again point out that size 1 missiles are how you win the missile game purely because you need ~3 antimissiles per missile, which is 3 magazine space, so you need an absurd amount of magazine space to absorb size 1 attacks even ignoring cost efficiency problems.  'Conventional size' missiles, such as 4 or 6, always lose the magazine attrition minigame. 

which is why small missiles are broken even disregarding everything else

[jseah]

If you can squeeze a str-5 warhead into the same size missile at a cost of 5% in hit probability, you'll have a better design.

Nah, 5% hit probability is way too much.  Going from 20->25% interception rate is the difference between expending all missiles to no effect versus punching through PD. 

Maybe at 1%, I might take the str-5 over the str-4. 

[Theokrat (OP)]

How does this affect the calculation if we take into account PD hit chance as follows:
Assuming a 20% AMM hit chance against a standard 1WH per MSP, how would raising or lowering the WH per MSP change the scenario, at the various tech levels?

At WH4 tech, 0.25 MSP is warhead to get 1 WH per MSP.  At WH5, only 0.2 of the MSP is warhead. 
At increasing tech, less of the missile is WH and fuel and thus the proportional speed increase is less when you decrease warhead and likewise the proportional speed decrease for increasing warhead is also less. 

0.05 of an MSP is not that much difference in terms of speed.  At WH5, size 4 missile might do better with strength-5 warheads instead of 4 and eating the lower speed (and thus higher interception rate from enemy AMMs)

Well the analysis presented is relatively independent of technology. As I said , I try to determine the best absolute missile size, but not the relative size of the components. We can simply assume that we knew the best relative size, and taking this as given determine the best size.

There might be a bit of confusion because I expressed the final tradeoff in derived variables, i.e. the individual warhead-strength (and not the missile size), and the number of missiles that the enemy can shot down (instead of the number of AMM defences he has). This might be a bit confusing, but the reason is that these are independent of your preferences. For instance a fast missile is more likely to dodge enemy AMM fire, so you have to scale the x-axis in the last graph, depending on how far your missiles go. I don't know your preferences or your technology, so I decided to remain with the raw #of missiles shot down. Similarly, the size of the missile will depend on technology, and preferences, but I say it should result in a strength-4 warhead.

Lets take an example and assume you have the technology WH5 and that you devote 40% of missile space to the warhead. So in order to get a strength-4 warhead you would need a size-2 missile. Importantly, the 40% is determined by other factors, such as your preference for range, speed and hitchances. If you preferred missiles that go faster or further you might want to choose a size-3 missile. Or if you have a much better technology, you could go for a size-1 missile.

Importantly, the procedure is two-stepped: You first determine the relative composition to get the primary characteristics you desire (range, speed, hitchance). Then, in a second step you choose the absolute size, such that the total warhead strength of one missile is either 4 or 9.

I concede that one might want to keep the next technological step in mind. Missiles are built much faster than ships, and missiles need to be fired from launchers. So when the next technology level would allow for a very good size-1 missile design and you are not currently in the middle of an important war, you might as well pick a slightly suboptimal size-1 design now and replace the missiles later.

Also, any chance of releasing the source and binary of the program you wrote to do the simulations?  I certainly don't think you did ten thousand live fire trials in Aurora.  =)

Actually I did this in Excel. Certainly not the most elegant program for the task, but quickly “programmed”. Sure I could share the file, but should do some clean-up first and write a short readme. Indeed doing this in Aurora would be rather tedious, seeing that 10,000 runs of up to 144 shots were required for each of the 85 datapoints in the last two graphs, so overall some 60 million or so missile shots ;-).

Excellent analysis, Theo. Size-4 looks like a good GP warhead, when facing unknown PD defenses and armor.

Thanks, appreciated ?

You need to add "and has no ability to shoot back at us, and has no shields" to the caveats in this statement.  If you're under fire in the engagement, then RoF (which you've ignored) becomes critical and heavily weights the analysis in the direction of missiles with an RoF of 5s (or size-1, if you don't have the tech for a 5s RoF).  Similarly, if the enemy has big enough shields that they can significantly recharge between salvos, the RoF again becomes important.  I expect that if you presented your data in terms of time to destruction of the enemy (assuming destruction at a specific number of internal damage points) that these effects would be pronounced.

I agree on the shields issue which I will add as a caveat. I did mention though that I ignored the effects of a higher rate of fire of smaller launchers and the resulting quicker kills (fifth paragraph).

However I am not sure that it is a very important aspect. Consider this: The rate of fire of even large launchers is very small compared to the time it takes for the missiles to travel to maximum range. So even small differences in the speed or range of the missiles of two opponents will typically result in the missiles of one guy arriving much earlier than those of the others. Say for example tow opponents who both have a range of 50m km. Blue’s missiles go 50,000km/s, Red’s missiles go 40,000km/s. Thus it takes Blue’s missiles 1,000s, while Red takes 1,250s. Let’s say Blue could fire 3 salvos, either with small launchers with a rof of 5s, or large launchers with a rof of 50s. Would this make a difference? Well no, the last salvo of the large launchers would still arrive before the first salvo of Red, so it would not matter if Red receives all hits within 15s or 150s. And the example is quite generous IMO, with only 250s between both opponents.

So yes, you are right, smaller missiles can cause kills much quicker and this advantage is not reflected in the analysis above. But I feel that overall the time it takes to a launch multiple salvos is small compared to the sluggish salvo-exchange in void space anyway. Of course things would look much different close to jumppoints, where damage per second become a much more relevant variable than damage per magazine space.

One thing I realized from a post in the other thread - I've been assuming that size-1 missiles (and I do mean size-1, not strength-1) are better than size-2 missiles, since they'll have a 2x faster RoF.  This isn't necessarily true for high reload techs, since reload times have a 5s floor.  The correct statement is that, for the sandblasting regime, you want to put the biggest warhead that fits (assuming good range/performance parameters) into 5s reload-time missile.  As jseah points out, especially at low tech, this means that you won't be able to squeeze in warheads that have perfect-square strengths.  A different way to say it is that missiles are quantized in terms of size, which means that comparing e.g. strength-4 to strength-5 warheads in the abstract is missing an important design parameter.  If you can squeeze a str-5 warhead into the same size missile at a cost of 5% in hit probability, you'll have a better design.

John

Personally, I also highly value another benefit of size-1 missiles: You do not need different AMM and ASM launchers. If, for example, one normally devotes 50% of launcher space to AMM-launchers and 50% to ASM-launchers, then by moving to size-1 one can double the size of ones ASM and AMM salvos simultaneously!

I would like to point out that even at later techs (when its viable to use a size-2 rof 5s launcher), you might still be better off using size-1 missiles.

I would like to again point out that size 1 missiles are how you win the missile game purely because you need ~3 antimissiles per missile, which is 3 magazine space, so you need an absurd amount of magazine space to absorb size 1 attacks even ignoring cost efficiency problems.  'Conventional size' missiles, such as 4 or 6, always lose the magazine attrition minigame. 

which is why small missiles are broken even disregarding everything else

Yes, this is correct. The problem is that you need 1 point of damage to destroy a missile, which is grossly high when you think about it.

Put it like this: 1 point of damage can destroy a missile or destroy one armour box. One missile can be 0.05 Hull Space, while an armour box is about 0.2 Hull Space (Duranium). Or the other way around: 1 HS of armour can absorb 5 damage points, while 1 HS of missiles can absorb 20 damage points!

That’s right: Missiles (fragile tin cans full of ignitable fuel, explosives and fissionable material traveling at  high speeds) are about four times better at absorbing damage than armour (the material designed specifically for this purpose). And this is even ignoring that it’s much harder to cause the damage to missiles in the first place due to their high speeds.

Therefore my proposal to Steve: Allow missiles to have a 0.1 warhead, which is sufficient to kill other missiles, but does not cause damage to ships. Simultaneously allow fractional missile launcher sizes and missile sizes.  This way the smallest viable ASM would still be around size-0.5 (due to the requirement to have a strength-1 warhead), while AMMs could be size-0.1 with a 0.1-strenght warhead. This would make AMM a viable option again and avoid above mentioned gross relation between damage absorbtion.

[jseah]

In addition to allowing micromissiles, the game could track missile types and known characteristics in the diplomacy/intel screen.  The player could then check/uncheck an intercept button which would cause their PD launchers to ignore/fire on that type of missile. 

A good rule of thumb would be to ignore anything without at least a size 1 warhead. 


Bonus:
Allow the player to set overriding PD ratios for each missile.  The ships will use that ratio in the intel screen instead of the ones in their firecontrol. 

Would allow the player to set PD rates for each missile type independently.  So a slow WH1 missile bus launching a speedy WH4 ASM would have 1:1 for the bus and 3:1 for the ASM. 

[sloanjh]

I agree on the shields issue which I will add as a caveat. I did mention though that I ignored the effects of a higher rate of fire of smaller launchers and the resulting quicker kills (fifth paragraph).

I actually did see that.  I was just trying to point out that "larger missiles are certainly better" is a pretty strong conclusion for an analysis that's ignoring a lot of effects.

The way that I think the overall situation should be phrased is something like the following: "For non-combatants (i.e. ships with no AM defence capability), or for ships that can be taken out with a single salvo, larger warheads are better.  For hardened targets (i.e. ships with significant AM defence and armor) high RoF missiles are better."  This is the result of combining the better damage efficiency of large warheads with the offsetting effect of higher susceptibility of small salvos to anti-missile fire (in which 5s vs 50s salvo intervals can be significant).  A different way to say this is that in certain regimes big warheads are more effective, while in others big salvos are more effective.  The question is "where is the crossover". 

Consider this: The rate of fire of even large launchers is very small compared to the time it takes for the missiles to travel to maximum range.

Actually, I had considered that case - that's why I phrased the "under fire" bit like I did   The counteracting effect comes back to AM fire.  For larger missiles, you'll want to use reduced-size launchers in order to bump up the salvo size (since salvo size decreases the efficiency of e.g. point defence fire), especially if you're using FAC.  I typically end up in a situation with size-4 missiles with a 20 minute reload time.  This tends to be roughly the travel time to the missile range, so RoF can play a role here.  With a size-1 missile, you don't need to use reduced-size in order to get decent salvo sizes, and so you can go to extremely high RoF and flush your entire missile load (for an FAC) in what is effectively a single salvo.

That being said, you're right - missile defence saturation (and AMM ammo exhaustion) and strong shields are typically going to be bigger reason for the advantage that the large salvo size and high RoF of smaller missiles gives.

Personally, I also highly value another benefit of size-1 missiles: You do not need different AMM and ASM launchers. If, for example, one normally devotes 50% of launcher space to AMM-launchers and 50% to ASM-launchers, then by moving to size-1 one can double the size of ones ASM and AMM salvos simultaneously!

Yep - I always carry some "slug" (big warhead, size-1) missiles on my AMM ships.  They're also REALLY nice to have if it turns out that the enemy is using armored missiles.

I would like to point out that even at later techs (when its viable to use a size-2 rof 5s launcher), you might still be better off using size-1 missiles.

Yeah - that wasn't a very bright idea on my part, but not due to the interchangability argument.  The problem is that size-2 launchers give you 1/2 the salvo size, which means that you're trying to straddle two different regimes (large warhead vs. large salvos).  If you are going for the large salvo regime, you need to be using size-1 missiles.

Put it like this: 1 point of damage can destroy a missile or destroy one armour box. One missile can be 0.05 Hull Space, while an armour box is about 0.2 Hull Space (Duranium). Or the other way around: 1 HS of armour can absorb 5 damage points, while 1 HS of missiles can absorb 20 damage points!

This is the sort of argument that is very compelling to Steve, since he hates this sort of inconsistency.  I would recommend putting this argument somewhere where it's more obvious to him, for example a post in the official suggestions thread. 

Therefore my proposal to Steve: Allow missiles to have a 0.1 warhead, which is sufficient to kill other missiles, but does not cause damage to ships. Simultaneously allow fractional missile launcher sizes and missile sizes.  This way the smallest viable ASM would still be around size-0.5 (due to the requirement to have a strength-1 warhead), while AMMs could be size-0.1 with a 0.1-strenght warhead. This would make AMM a viable option again and avoid above mentioned gross relation between damage absorbtion.

The problem is that there's some exploit history here.  Basically, people were making VERY tiny str-0 missiles and using them to soak up AMM fire.  I think you're right that he needs to figure out a way to address the damage imbalance - I just don't know what it will be.  I personally think that the thing that's broken is the perfect scaling between size-1 missiles and e.g. size-10 missiles (assuming no armor) - if there were a fixed size penalty (e.g. 0.2 or even 0.5 missile size points) for all missiles, this would tilt things more in the direction of big (or at least bigger) ASM missiles (by offsetting the salvo size advantage of size-1 missiles).  This might, in turn, permit str-0 warheads which could only kill missiles (note that missile armor would need to be adjusted too) without being susceptible to exploit. 

John

[sloanjh]

Nah, 5% hit probability is way too much.  Going from 20->25% interception rate is the difference between expending all missiles to no effect versus punching through PD. 

Maybe at 1%, I might take the str-5 over the str-4. 

I meant a relative 5% penalty, not absolute, e.g. hit probability at 5KKm/s goes from 80% to 80*0.95 = 76% .  Since this will usually be caused by a change in speed, the probability of intercept will go up by 5%, i.e. 20% intercept chance --> 21%, which oddly enough is the 1% difference that I think you're talking about

John

[TheDeadlyShoe]

The problem is that there's some exploit history here.  Basically, people were making VERY tiny str-0 missiles and using them to soak up AMM fire.  I think you're right that he needs to figure out a way to address the damage imbalance - I just don't know what it will be.  I personally think that the thing that's broken is the perfect scaling between size-1 missiles and e.g. size-10 missiles (assuming no armor) - if there were a fixed size penalty (e.g. 0.2 or even 0.5 missile size points) for all missiles, this would tilt things more in the direction of big (or at least bigger) ASM missiles (by offsetting the salvo size advantage of size-1 missiles).  This might, in turn, permit str-0 warheads which could only kill missiles (note that missile armor would need to be adjusted too) without being susceptible to exploit.

Well the first and most obvious way would to eliminate or heavily flatten the reload rate curve, normalizing at size 4 or thereabouts.  This would dramatically reduce the heightened DPS that smaller missiles achieve.   It would also make antimissile defence more interesting, in that absolute capabilities would matter more relative to absolute magazine size. (For example, if your size 1 launcher has a 30s reload rate, it might be wise to cart around some AMM box launchers for defending against unexpected salvos.)

Another method is to increase the relative importance of the size-independent missile attributes - armor, ecm, and active sensors.  Armor is dead weight for all but very large missiles currently, since any weight devoted armor could be devoted to the engine instead. Thus every point devoted to armor makes the missile easier to hit (relatively speaking) and so armor can be self defeating in its primary purpose.  ECM is essentially pointless for similar reasons - a faster engine spends less time in the AMM envelope and is harder to hit with beam PD, exactly the same result as applying ecm.  Even if ECM was more powerful, it's a lot easier for a ship to mount ECCM than for a missile to mount ECM.  Active sensors are the most useful of the three, but are essentially a luxury.

  A reworked electronic warfare model would go a long way in this respect - I've been thinking something like a 50% miss rate for an ECM-1'd target, while ECCM only provides a chance of ignoring ECM. That would simultaneously make missile ecm worthwhile and proportionally reduce the effectiveness of mass missile spam attacks.   Again looking at reworked electronic warfare, perhaps active sensor missiles could continue to seek targets even if they roll a miss.  So the same salvo would attack round after round until all missiles either hit or are destroyed.  IMO this would provide an interesting balance between agility and sensors and increase the importance of final defensive fire. 

I plan to have house-rule avionics in my 5.7 campaign - current plan is 0.2 + 0.1/msp points of armor per missile.

[CheaterEater]

Well the first and most obvious way would to eliminate or heavily flatten the reload rate curve, normalizing at size 4 or thereabouts.   This would dramatically reduce the heightened DPS that smaller missiles achieve.    It would also make antimissile defence more interesting, in that absolute capabilities would matter more relative to absolute magazine size.  (For example, if your size 1 launcher has a 30s reload rate, it might be wise to cart around some AMM box launchers for defending against unexpected salvos. )

What about making the reload rate cost some size? For example, if every reload rate above 1 costs 1 HS, a size 1 launcher with reload rate 6 would be 5 HS, while a size 4 launcher with reload rate 6 would be 9 HS.  At reload rate 1, the size 1 launcher puts out 2 MSP of missiles per minute per HS, while the size 4 launcher puts out 1/2 MSP of missile per minute per HS.  At reload tech 6, the size 1 launcher would put out 2 MSP of missiles per minute per HS (no damage advantage) while the size 4 launcher would be putting out 4/3 MSP of missiles per minute, a significant advantage.  You can tweak the reload rate cost to balance it out then.

[Erik L]

What about making the reload rate cost some size? For example, if every reload rate above 1 costs 1 HS, a size 1 launcher with reload rate 6 would be 5 HS, while a size 4 launcher with reload rate 6 would be 9 HS.  At reload rate 1, the size 1 launcher puts out 2 MSP of missiles per minute per HS, while the size 4 launcher puts out 1/2 MSP of missile per minute per HS.  At reload tech 6, the size 1 launcher would put out 2 MSP of missiles per minute per HS (no damage advantage) while the size 4 launcher would be putting out 4/3 MSP of missiles per minute, a significant advantage.  You can tweak the reload rate cost to balance it out then.

That is almost nullifying the benefits of the missile reload rate tech line. The issue is that larger missiles have a lower survivability than smaller missiles.

Possibly making armor a passive attribute linked to the armor tech line. At base armor you get .1 armor per MP of missile. Have that increase upwards as armor tech goes up. Smaller missiles are easier to knock down, larger missiles require 1 or more hits without depriving the missile of needed space for warhead/engine/fuel.

This could be extended to ECM also.

[CheaterEater]

That is almost nullifying the benefits of the missile reload rate tech line.  The issue is that larger missiles have a lower survivability than smaller missiles.

It doesn't nullify the benefits, especially if you tweak the penalty per reload level.  At 0. 1 HS/level, at reload tech 6 a size 1 launcher is 1. 5 HS, a significant penalty, while a size 4 launcher is 4. 5 HS, a relatively minor penalty.  It's still worthwhile at both levels though.  My first example at 1 HS/level was way overdoing it.  In any case, I was just offering a suggestion from a different angle is all.