2.5 Missile designs

[welchbloke (OP)]

I know these ASM and AMM missile designs aren't terribly clever for 2.5; what I did was start with some design from a much older edition so that I have a starting point to use for advice. I think they are too slow and probably have too much mass for fuel. What does a sensible AMM and ASM design look like in 2.5? I know there will be a variety of options given people's fleet doctrines but I haven't designed a missile in a long time and have no clear understanding of the 2.5 considerations/trade offs with options like ATG/decoys etc.

Engine tech is magnetic fusion, warhead tech is 2 stage thermonuclear (6xMSP).

Code: [Select]

Dart AMM

Missile Size: 1.00 MSP  (2.500 Tons)     Warhead: 1.02 (MW-2)    Radiation Damage: 1.02
Speed: 23,000 km/s     Fuel: 1,250     Flight Time: 22 minutes     Range: 29.78m km
Cost Per Missile: 0.930     Development Cost: 152
Chance to Hit: 1k km/s 230%   3k km/s 76.7%   5k km/s 46%   10k km/s 23%


Code: [Select]

Arrow ASM

Missile Size: 5.00 MSP  (12.500 Tons)     Warhead: 12 (MW-3)    Radiation Damage: 12
Speed: 16,000 km/s     Fuel: 3,750     Flight Time: 35 minutes     Range: 33.32m km
Decoys: 1 ECM-2     
Cost Per Missile: 6.20     Development Cost: 393
Chance to Hit: 1k km/s 160%   3k km/s 53.3%   5k km/s 32%   10k km/s 16%


Any advice/alternate designs gratefully accepted.

Welchbloke

[Demonides]

I prefer faster AMM/ASM (Magneto-Plasma / 5xMSP)

Code: [Select]

Missile Size: 1 MSP  (2.5 Tons)     Warhead: 1.0    Radiation Damage: 1.0
Speed: 46 800 km/s     Fuel: 150     Flight Time: 4 minutes     Range: 10m km
Cost Per Missile: 1.42     Development Cost: 188
Chance to Hit: 1k km/s 468%   3k km/s 156%   5k km/s 93.6%   10k km/s 46.8%

Code: [Select]

Missile Size: 6.0000 MSP  (15.00000 Tons)     Warhead: 10    Radiation Damage: 10
Speed: 24 000 km/s     Fuel: 2 093     Flight Time: 16 minutes     Range: 23.2m km
Active Sensor Strength: 0.26   EM Sensitivity Modifier: 8
Resolution: 25    Maximum Range vs 1250 ton object (or larger): 2 379 229 km
ATG: 20%     Retarget Capable
Cost Per Missile: 7.216     Development Cost: 424
Chance to Hit: 1k km/s 288%   3k km/s 96%   5k km/s 57.6%   10k km/s 28.8%


[Nori]

For your AMM. The speed is quite low and your range is way more than you need. Sensors simply can't track missiles out that far. I aim for sub 5m range.
Also, you should check out fractional warheads. A 1WH will 100% kill any missile but you could halve it and still kill any missile 10MSP or below. Personally, I've been using 0.3WH size, it'll kill any missile 6MSP or below and still has a 60% chance to kill a 10MSP missile.

Read more here: http://aurora2.pentarch.org/index.php?topic=13090.msg164041#msg164041

ASM seems fine. Probably easy to shoot down and not particularly fast, but it hits hard for its size.

I find retargeting useful across the board. If you fired your ASMs against a ship that was traveling at 5k you would miss with 68%. Retargeting would let them keep trying to hit till they run out of fuel or are shot down. I put it on all my ASMs though it would probably require a slightly larger missile.

[Ulzgoroth]

Retargetting isn't a trivial add on either kind of missile, but it's quite good.

On AMMs, getting it while retaining high enough performance to make the intercept can be a design problem or push you to build larger AMM. (But a size 2 AMM that always hits is still better than a size 1 AMM that hits 30% of the time...)

On ASMs, the re-attack happens on a separate tick so the missile has to challenge all the enemy final defense fire again with fewer friends to draw fire, unless the targets don't have fast-cycling defenses.


For the OP, yes much too slow. Are you using engine boost? You probably want more of it. If you haven't researched it all yet it's a cheap tech and extremely important for missiles.


At the tech level in play it may not be important, but note that ASMs will eventually need ECCM: target ships with missile jammer ECM become literally unhittable if they've got a big enough ECM advantage.

[nuclearslurpee]

Code: [Select]

Dart AMM

Missile Size: 1.00 MSP  (2.500 Tons)     Warhead: 1.02 (MW-2)    Radiation Damage: 1.02
Speed: 23,000 km/s     Fuel: 1,250     Flight Time: 22 minutes     Range: 29.78m km
Cost Per Missile: 0.930     Development Cost: 152
Chance to Hit: 1k km/s 230%   3k km/s 76.7%   5k km/s 46%   10k km/s 23%


This is really, really, really way too slow. At MP Drive tech level it is entirely reasonable to have AMMs with speeds in the 60,000 to 80,000 km/s range (although the higher end of this range is impractical). To my eyes it looks like your problem is fuel loading, 1,250 L is half of your MSP dedicated to fuel which is excessive. Convert 90% of that into engine tonnage and your AMM will look a lot better. Otherwise this design looks okay for a size-1 AMM. You could go larger (1.5 or 2.0 MSP) and mount a retargeting module if you wanted to, but I think since the bug fix in 2.5 this is not critical.

Code: [Select]

Arrow ASM

Missile Size: 5.00 MSP  (12.500 Tons)     Warhead: 12 (MW-3)    Radiation Damage: 12
Speed: 16,000 km/s     Fuel: 3,750     Flight Time: 35 minutes     Range: 33.32m km
Decoys: 1 ECM-2     
Cost Per Missile: 6.20     Development Cost: 393
Chance to Hit: 1k km/s 160%   3k km/s 53.3%   5k km/s 32%   10k km/s 16%


Here the fuel problem is even worse as you are dedicating 60% of your missile size to fuel, which is way too much. The problem here appears to be that you are using the maximum EP modifier which makes fuel consumption too high for the needed range. You will get much better performance by reducing the EP modifier and cutting the fuel load by a lot to increase engine mass.

Additionally, multiple-warhead on a ASM is usually not too useful (unless you intend to use these as anti-fighter/FAC missiles, then maybe it is useful). It is usually better to concentrate your strike power into a single warhead to try and hole enemy armor as deeply as possible. Multiple warheads are usually better for AMMs when the fragmentation effect can improve hit rates.

[welchbloke (OP)]

Thanks to everyine that has taken the time to post a reply. A lot of mechanics have changed since the last time I designed a missile in Aurora.

As Nuclearslurpee says, I have spent way too much of my mass on fuel for both designs; something that I had already suspected but helpful that people with more experience have confirmed it. I've redesigned the missiles based upon the advice so far:

Code: [Select]

AMM

Missile Size: 1.00 MSP  (2.500 Tons)     Warhead: 0.6 (MW-3)    Radiation Damage: 0.6
Speed: 72,000 km/s     Fuel: 250     Flight Time: 62.1 seconds     Range: 4,471,200 km
Cost Per Missile: 2.15     Development Cost: 231
Chance to Hit: 1k km/s 720%   3k km/s 240%   5k km/s 144%   10k km/s 72%

If I've done the maths correctly this AMM fractional warhead has a 100% kill against anything up to size 12 (assuming it hits). Also this design has 3 warheads, can someone point me at how this affects %age chance to hit for AMMs?

Code: [Select]

ASM

Missile Size: 5.00 MSP  (12.500 Tons)     Warhead: 12    Radiation Damage: 12
Speed: 26,160 km/s     Fuel: 175     Flight Time: 22 minutes     Range: 33.75m km
Decoys: 1 ECM-2     ECCM-1     
Cost Per Missile: 7.32     Development Cost: 427
Chance to Hit: 1k km/s 261.6%   3k km/s 87.2%   5k km/s 52.3%   10k km/s 26.2%


I've backed off the powerboost for this design, significantly reduced the fuel mass and increased the engine mass.

Thoughts?

Welchbloke

[nuclearslurpee]

I would personally want the ASM to be somewhat faster. Maybe cut the warhead down to about 9 or so and add that mass back to the engines? Nominally ASMs can be around half the speed of AMMs at the same tech level as you do need speed to penetrate enemy anti-missile defenses.

If I've done the maths correctly this AMM fractional warhead has a 100% kill against anything up to size 12 (assuming it hits). Also this design has 3 warheads, can someone point me at how this affects %age chance to hit for AMMs?

Not correct, sorry. The way multiple warheads works is that the total warhead strength is divided by the number of warheads, so you have three WH-0.2 fragments that will have 100% kill rate on missiles up to size 4. This isn't necessarily a bad thing. Against a size-8 missile for example each fragment has a 50% kill chance, which is the same as a WH-0.4 fragment, but having more fragments may help chew through missile decoys and give you more hits on the actual missiles - I'm not sure how the statistics work out here in specific cases.

[welchbloke (OP)]

I would personally want the ASM to be somewhat faster. Maybe cut the warhead down to about 9 or so and add that mass back to the engines? Nominally ASMs can be around half the speed of AMMs at the same tech level as you do need speed to penetrate enemy anti-missile defenses.

If I've done the maths correctly this AMM fractional warhead has a 100% kill against anything up to size 12 (assuming it hits). Also this design has 3 warheads, can someone point me at how this affects %age chance to hit for AMMs?

Not correct, sorry. The way multiple warheads works is that the total warhead strength is divided by the number of warheads, so you have three WH-0.2 fragments that will have 100% kill rate on missiles up to size 4. This isn't necessarily a bad thing. Against a size-8 missile for example each fragment has a 50% kill chance, which is the same as a WH-0.4 fragment, but having more fragments may help chew through missile decoys and give you more hits on the actual missiles - I'm not sure how the statistics work out here in specific cases.

Thanks for the correction, I'll drop it to 2 fragments and see how it plays out.

For the ASM, I'll play around and see what I can optimise for a 35k km/s speed version.

Welchbloke

[Ulzgoroth]

With only ECCM-1, despite my previous remark on it, you might want to take the ECCM back off.

Maybe not. It's not all that big relative to even your comparatively small AMM.

The effect of ECM/ECCM on your attack, per the source, is that your chance to hit takes a multiplier of (100% - 20% * ECM disadvantage). That means the possible benefits of ECCM-1 depend on the target's missile jammer ECM level:
0: no benefit.
1: 25% increase in hit chance (80% -> 100%)
2: 33% increase in hit chance (60% -> 80%)
3: 50% increase in hit chance (40% -> 60%)
4: 100% increase in hit chance (20% -> 40%)
5: Makes hitting possible (0% -> 20%)
6+: No benefit (0% -> 0%)

So if your enemies are using ECM at all the gain is substantial, but not huge unless they're using a lot of ECM. Which may be unlikely if they're at a tech level these missiles will be able to match.

Note that this rapidly changes as your ECCM level goes up, since ECCM 2 improves your hit chance by two steps rather than one against targets with 2-6 missile jammer ECM.


Also note that ECM for missiles is completely different, making ECCM for AMMs an whole other calculation that's less likely to be appealing.

[nuclearslurpee]

With only ECCM-1, despite my previous remark on it, you might want to take the ECCM back off.

The counterpoint here is to ask what we would replace the ECCM with, and how does that influence the resulting hit chances and net damage done by a missile salvo? If the target has ECM-1 jammers for instance, can we replace ECCM with some other system(s) that will result in more than 25% increase in damage delivered to the target? The answer is "maybe" which means it is not a trivial consideration and we have to actually look at different candidate missile designs and try to calculate which ones will work the best.

I don't mean this as a "no, actually..." post, just to provide an alternative perspective for OP to consider. 

(One other thing to think about: ECCM may be useless against a race that has no ECM, but on the flip side if a race doesn't use any ECM maybe they are lower-tech in general and we do not need to optimize for this particular case. In that sense, it is perhaps worth optimizing to defeat the more challenging opponents who have more ECM.)

[captainwolfer]

ECCM on offensive missiles is basically always worth it unless the missiles are for killing FACs or fighters, so far I've found most spoiler and NPR ships have missile jammers.

[welchbloke (OP)]

Thanks for the responses everyone - really useful feedback.

Welchbloke

[Mint Keyphase]

For AMM I just shove the biggest engine I can fit into a size 1 missile with warhead power 1, with range barely covering the max sensor.

[JacenHan]

For AMM I just shove the biggest engine I can fit into a size 1 missile with warhead power 1, with range barely covering the max sensor.

For the new missile updates I have been doing pretty much this same thing, but on a size 1.5 missile with retargeting and a smaller warhead (somewhere between 0.5-1.0).

[paolot]

Maybe I am about to ask a nonsensical stuff...    
What about shields on large ASM?
Is it possible? Did anyone try it? If so, can it be effective in reducing damages/destruction of missiles?