Why is my lovely booster rocket suddenly disappearing parts?

[johnnyhandsome]

I've made an Asparagus booster rocket for future travel into deep space. There's a problem with one of the separate stages, where part of the rocket just disappears as stages drop away. See this gif:

What the heck is going on?

Here's the craft file if you want to investigate, it's stock. The Science lab at the top is the separating rocket pairs, so one knows where to watch.

Edited August 9, 2014 by johnnyhandsome
adding link to craft file

[Master Tao]

What does the flight log (Alt+F3) say after decoupling? Also, the craft link isn't showing up.

[Kryxal]

I think the seperatrons are causing this ... certainly I'm seeing massive sudden overheats of a couple of engines.

[johnnyhandsome]

Whoops, link added. Flight file says a lot of things were damaged by various Sep Motors.

[ProjectGemini]

Whoops, link added. Flight file says a lot of things were damaged by various Sep Motors.

Then yeah, the separation Motors are overheating your parts. Remove a few.

[Master Tao]

Yes, so Kryxal and ProjectGemini are right. "sepMotor1" is the internal name for Sepratrons.

I find one particular setup works best for Sepratrons: vertically center them on the outside of the booster, nozzle up. You should be able to set that up even with asparagus staging.

[johnnyhandsome]

Ok removing the Seps seems to work, but the odder problem is that the rockets that were disappearing are overheating, while others are not. Strange.

[Master Tao]

That sounds like the strange heat logic issues. Try putting very short tanks between long tanks and engines.

[SRV Ron]

Looks like a combo of the seperatrons and the fact that the two engines reach detonation from overheating just after staging.

A small fuel can under each big one will eliminate the overheat. Also, if you are not turning when staging, you won't need the seperatrons. Mod example similar to your design.

[Kerbart]

Ok removing the Seps seems to work, but the odder problem is that the rockets that were disappearing are overheating, while others are not. Strange.

Well they seem to be overheating to the point of exploding. And when they explode they disappear. Not really that strange that they're disappearing