Tug falling apart

[Spaceisbeautifulul]

Hey all, I was trying to create a Apollo-style Mun mission, and my tug (service module) keeps falling apart in launch.

I do my gravity turn, and all that jazz, and then halfway through the launch, the

THIS PART just collapses.

Here's a picture of the whole rocket:

It gets going pretty fast, so could it just be collapsing under pressure?

I tried launching it 5 different times, and it all happened more or less at the same time, so its not just some weird glitch.

And as you can see I tried strutting it up a lot, it didn't help.

Thanks in advance!

PS: The only mod used is the chatterer: (link incoming!) http://kerbalspaceprogram.com/chatterer/

[EndOfTheEarth]

All your strut connections are to the engine, instead of higher up, where the actual weight is.

Try moving the radial set of struts so that they connect from the radial boosters to the SM main fuel tank.

Also if this is a mun tug, then you might be better off with a different engine.

[Spaceisbeautifulul]

Alrighties I'll try that.

Edit: It still fell apart! Maybe its a bug with the game?

Edited June 20, 2013 by Spaceisbeautifulul

[capi3101]

Hmm...try stitching the decoupler to that Rockomax adapter. Just run a couple of struts between the two. Maybe also between the adapter and that tank it connects to on the booster. If it still fails, try to launch at 2/3 throttle and see if that has any effect; the payload on my heavy TSTO lifter will come off if I run the third stage engine much faster than 1/3 during orbital insertion, so too much booster could also be the problem.

Out of curiosity, what are your stage TWRs? If they're much above 2.2 you definitely want to throttle back.

[falofonos]

Most likely cause of that part failing is through compression due to high g. As your booster stage loses fuel mass it gains TWR to the point where you are crushing the stack with thrust.

Try reducing the number of struts, 1 from each exterior tank to the mission capsule and 6 from the booster stage to the mission capsule.

Make sure you aren't exceeding 2 g acceleration by throttling back. Decouplers pretty much explode if you put them under too much load and at 3g any mass they support will be too much.

Edited June 20, 2013 by falofonos

[EndOfTheEarth]

Alternately, switch out that engine, tiny decoupler, and conical bit and replace it with the large decoupler and poodle engine.

I think falofonos is on the right track though. I've run into similar issues for similar reasons.

[Sirrobert]

Alternativly reduce the acceleration. You'll still get where you need to go, it just takes a little longer.

Mechjeb 2,0 has an option to limit acceleration to x m/s2 (you pick x yourself)

[Spaceisbeautifulul]

Alright, so it looks like the best way to fix it was to throttle down. Thanks all!

Errr, moderators? Close thread?