The Capital Ship Armor Thread

I came up with a solution to my weakness versus drones.

It comes with missiles. 150mm diameter missiles with 30 seconds of burn time at nearly 7 gravities, for a powered range envelope of 60 kilometers and a burnout velocity of over 4000 meters per second. The warhead is a 7.5 kilogram flak bomb.

These missiles are specifically designed to be deployed in tactical engagements instead of launched in waves on the strategic map. Each of its two launchers cycles once every two seconds. It carries over 400 missiles in its magazines.

The best part? Each missile costs less than 200 credits. You can empty your magazines for less than half the cost of a single Stinger drone.

Please take screenshots. :3 -- UserDesigns.txt (42.06 KB)

Edit: I'm very proud of our scientists on this one. They went hard to work with pocket calculators and a borrowed copy of Kerbal Space Program to design these munitions. Where else can you get 5 kN, 3.10 km/s decane/LOX rocket engines for less than the two one-credit chips clinking together in your pocket? Buy Salacia Space Force surplus today!

Edit #2: We take no responsibility for magazine explosions resulting from the use of lithium turbopumps for pressurizing LOX. Read the damn instruction manual.

Yeah, I'm not super happy about the missile guidance algorithms: they seem to be either full pursuit or naive proportional navigation, both of which are really suboptimal. If/when there's a modding API, adding an EPN guidance button will be high on my to-do list.

I may need to break down and make a 3 MW laser optimized for irradiance at range. I hate doing it, because I love CIWS and countermissiles, but needs must.

I've got a small nuclear warhead I was considering placing on the missiles. It's not as small or as cheap, but my navy lacks the ability to compress fusion fuel to those densities. I limit myself to 800 kg/m^3 and say that I'm using a deuterated/tritiated hydrocarbon or something. Still, I could be using interceptors with 300t warheads on them, which is still no joke when you're expending them like candy.

Anyway! This is an armor thread. How'd the armor do? The fact the destroyers survived the drones running out of gas seems encouraging.

Edit: 45 kg is the lowest you can go with a stoich mix of decane and oxygen, unfortunately. My original paper design only called for 30 kg of propellant. I may need to switch my small missiles to a different mix, but I really love decane's density and the high burn temperature of decane/LOX.

Good to hear that about the armor! Amorphous carbon seems to work pretty decently as a budget alternative to RCC for spall liner duty.

I'm consistently shocked by how well that 5mm of osmium does compared to 2.5cm of steel. The mass is terrifying, but a little seems to go a long way.

The main thing I've had against drone warfare is the expense of RTGs. However; I've read the reactor thread and was clearly ignorant of just how tiny a reactor could be made. I probably won't push the limits as drastically as they do -- this is the navy of cheap practicality, after all --  but a sub-ton, 75 cm diameter reactor made as cheap as humanly possible is probably high on my list of priorities. I want to do something unique with my drones, though...maybe something missile-related. Or drones that launch micro-drones. Actually, that sounds amazing.

I'll also see about clearing away any unused modules, or creating a separate UserDesigns files for experimentation and stuff I want to share.

I love those. They're tiny and adorable. Impressive dV performance, too. I love using missiles in tactical engagements.

If you look at blothorn's post above, the missile he posted there is my 15.0 cm design with the original 15kg flak bomb swapped out for a small nuclear warhead. They cost about 160c each in the flak configuration. Unfortunately, decane/LOX has a lower limit on propellant mass of about 45.0 kg due to the stoich ratio and the 10.0kg minimum tank size.

I'll probably try a monoprop design tonight. I really want to keep the small diameter, but I've noticed that puts a pretty hard cap on your gimbal angle, which has some pretty significant repercussions in terms of maneuverability. I'd love to get my missiles and launchers down to the size where drones can use them, though. (We should really start another thread centered around cost-effectiveness in all its forms!)

To bring this back to armor discussion though: has anyone studied the effects of both flak and pure kinetic missiles against armor? I may start testing to counter those threats along with cannons, since those seem to require a different approach than hypervelocity stuff.

I've been blowing up some test hulls, nothing particularly extensive. How flak behaves depends on the grain size though. Small-grain flak can generally be handled much like small-caliber hypervelocity rounds, whipple shields stop them nicely. However, because each missile puts out hundreds of fragments (or thousands, for medium/large flak missiles) and flak salvos often contain 50+ missiles, a full salvo will often fully deplete the whipple shield where it hit and leave the area looking like it got hit by the sandblaster of the gods. Especially since right now, the guidance computer likes to detonate point-blank no matter what the arming distance is.

Honestly, other than "don't get hit" I'd say the best way to deal with flak missiles is to make sure you don't put anything that you're going to miss between your main radiators, and put said radiators forward enough that your engines don't get caught in the flak cone. The point-blank detonation means that very few fragments will hit the radiators themselves (though a large enough salvo can still take them out), so if the inside of your ship is arranged right, you might be able to just let the missiles core your ship and you'll only lose one fuel tank.

Setting that aside, a few cm of vanadium chromium steel can render important things like the crew and reactor immune to stray flak hits. I haven't tested osmium but it would probably work too. Ever since I moved those two components into a VCS citadel, my test targets have only ever been hard-killed by radiator loss (though they tend to lose all their dV to engine/fuel hits long before that).

Diamond under silica aerogel also seems to be pretty amazing against nukes. When I put that on my test targets I could bombard them with gigaton nukes, they'd only ever lose engines and radiators, even after the aerogel had been mostly vaporized it took an extremely close hit to get through the diamond. With the armor fully intact they would survive direct hits almost unscathed, sans engines and radiators.

I looked into that, but decided the expense of a reactor was too much for the theme of my missile builds. I was able to squeak out a couple km/s from a 1kN ethylene oxide motor massing under 700 grams, which will drive a 14 kg missile at 5g for 30 seconds on 10kg of propellant. That meets my target of a powered range envelope of 50km or more, at a price tag of around 60c per missile.

For more capable missiles, the lower limits on propellant tank size are less of an issue, and I'm getting around 3.1km/s out of my larger decane/LOX engines where limiting diameter isn't quite as critical. I consider that a decent Ve for a munition, and not having to carry a generator is wonderful.

I may turn to resistojets for drones, though, particularly since compact nuclear reactors are so much cheaper than RTGs, and getting 600 kilowatts is actually easier than getting 6. I purposefully avoid the far limits of the customization and put a decent reflector on my drone reactors just as a theme/flavor thing, but they're still a solid choice and using a resistojet might allow me to shrink my drones down a little, which would be nice.