Guided missiles lacking punch

[ForScience6686]

Good morning everyone.  So today I have been messing around with a short range UAV for KSC patrol.  It is outfitted with 4 guided missiles that have performed quite well so far.  However, they don't do much damage, if any.  Now I was able to destroy the launch pad in one attempt.  But to a flying aircraft I had 4 hits that resulted in only one horizontal stabilizer being destroyed.  2 of the hits I am guessing were most likely destroyed by the engine exhaust, and 1 hit was to the right flap with no result.  Is there some trick to getting a bit more bang?  I am playing stock for the most part

Guardian 4

Guided missile

Damage?
 

I don't plan to mess around too much with defense contracts, so I think I would only consider small mods.  I am in 1.1.3 BTW.

TIA for any input.

[Andiron]

I don't think that jet engines have enough punch to speed up the missile enough. Try with a Spark engine and/or multiple twitch engines. The faster you will go, the more damage you'll make

[DrLicor]

Hmm I don't make guided missiles alot, but what I've done once, worked pretty good.

So I had kind of a 2 staged rocket, first stage is like you have now, but I had one with a little fairing on top, in the fairing where 10 small missiles, just boosters (used tweakscale). So when I was near the target, I staged, the 10 little booster hit the target first and finally the 'first stage'. Worked out pretty well with a lot of damage. 

[EpicSpaceTroll139]

I've found that having something with a high impact tolerance (for example, an I-beam) helps with damage. That or having a high mass. How full are the fuel tanks on your missiles?

[ForScience6686]

I have not experimented with rocket engines yet.  My thoughts are they just won't have much range like the jets.  My tanks are full except for the rear to help with flight performance.  I had better luck with adding one more full tank than what you see above.  My guess is the added mass helped.  But as far as damage goes, I've only had about 3 hits that were fatal to the performance of the plane, out of a couple dozen.  But these missiles were completely computer controlled, just targeted the plane.  Had much better luck with controlling them myself.  For now I'm happy with the current design.  I think I will try out a rocket engine next time.  Increasing mass would be the only other thing I can think of for better damage though.

[Plusck]

This question intrigued me, so I did a little investigating in pure stock 1.1.3.

And came upon a surprising result - the AV-R8 fin is actually pretty effective as armour. Far more effective than its fairly average impact tolerance suggests. I would expect that this impact protection extends to other control surfaces too...

So I created a test setup with a plane protected by AV-R8s, and tried a variety of missiles to see what might work best. I initially tried a long-range test but got quickly bored, and decided to get up close and personal instead. This is the set-up:

Spoiler

That's a Flea (minimal fuel) with 4x small elevons, probe core, empty Mk1 fuel tank, and a variety of things stuck on the front.

The main problem was that the AV-R8s were killing the missile. So I tried putting a number of objects on the front to get through: extended basic antennae seemed to work well, especially if combined with cubic struts and an OKTO core, but only sometimes... at other times only a single AV-R8 was damaged. The OKTO+antennae version had a failure rate of about 20%.

In the end, though, it was I-beams and the smaller modular girders that worked best.

I-beams clipped behind fairing, damage report

Modular girders clipped together, damage report

 

So yes, some plane parts survive attempts to destroy them surprisingly well in stock. You just need something that'll punch through them. One junior I-beam might be sufficient, but spacing them out a bit seems to work well. If you can't put them in the nose (because of intakes), I'd suggest surface attaching a pair and offsetting them forward a touch. They will cause drag but it shouldn't be too much of an expense.

[ForScience6686]

Nice, like to see someone adding some other tests to this.  Unfortunately I'm trying to stick to the mk0 sizes.  I think part of my problem is the testing is being done with sas set to target, and watching the missiles TRY and hit the target.  That's entertaining in itself.  When taking manual control the results are a bit better.  The best strike took out an entire wing, but many times a puff is all I get.  Hard to tell from the f3 screen, but my guess is the initial impact knocks the missile off course, and unless the fuel tanks collide, I get nothing.  

[Jarin]

I highly recommend switching to rocket engines of some sort. I'd suggest solid fuel, but you understandably want to stick to the mk0, so LF is where it's at. It's entirely likely that your plane can outrun your missiles with those puny mk0 jets. These are air-to-air, not cruise missiles, right?

[ForScience6686]

Correct the plane can out run it.  The idea of this plane is to patrol the ksc area and "protect" rockets on the pad.  Since there are no other aero space companies we could find on the planet, I'm only really concerned about ground units.  I have been able to destroy the launch pad, but that's it, was unable to damage any other structures.  I used the plane for target for time and entertainment reasons.  It's quite entertaining to watch the missiles gain on the target, and hopefully connect.  And the critical hits were fun to attempt a return landing.  I generally don't do defense contracts but I have a long wait until my next window and my Duna campaign begins.  I think I'll give the rocket engines a chance, but what would be the best part for the nose?  I would guess something with high impact tolerance, or would it be better to put something soft so the fuel tanks can make contact.  The f3 logs seem to indicate a need for fuel tank collision to cause damage.

[Plusck]

On 30/09/2016 at 10:11 PM, ForScience6686 said:

Nice, like to see someone adding some other tests to this.  Unfortunately I'm trying to stick to the mk0 sizes.  I think part of my problem is the testing is being done with sas set to target, and watching the missiles TRY and hit the target.  That's entertaining in itself.  When taking manual control the results are a bit better.  The best strike took out an entire wing, but many times a puff is all I get.  Hard to tell from the f3 screen, but my guess is the initial impact knocks the missile off course, and unless the fuel tanks collide, I get nothing.  

I went back to test this in mk0 - and got very similar results:

Spoiler

The two "M-Beam 200 I-Beam Pocket Edition" girders were surface-attached to the front fuel tank, then offset back so that just the ends poked out. It is quite manageable to fly without SAS and just pitch trim, top speed about 290 m/s at sea level. With SAS, it wiggles about. Impact speed was a lot slower than F3 indicates, but enough for the I-beams to destroy one AV-R8 and the precooler on the target.

Seriously though I don't know how you ever manage to hit anything with missiles. I almost managed to hit one of my stationary targets by flying at it properly (not just from launch clamps) after about 5 tries, then gave up...

[ForScience6686]

Flying in target mode, locked to target.  Adjust flight to keep prograde on target.  The sas in this game is too slow to react and over compensates.  It took some practice but I can hit the target almost every time now.  Granted, the target isn't evading.

Next time I get on I'll try out the I beams.  Thanks for the testing and input!

[Plusck]

Just now, ForScience6686 said:

Next time I get on I'll try out the I beams.  Thanks for the testing and input!

A pleasure!

If you want the setup I used for testing, the persistent.sfs file for this "default" sandbox 1.1.3 is here and the missile craft file is here