Docking Port within cargo bay suddenly explodes - do not use time warp!

[TheDog]

wow, the new heating is somewhat... weird... at least for me.

Mk2 spaceplane in LKO, some part still showing temp gauges from the ascend to orbit, but nothing serious, some bars slightly in the green.

Always been this way (in 1.0.2).

Attempting standard reentry - coming in shallow, hitting 60km at about 2300m/s.

Out of the blue the docking port jr. INSIDE the CLOSED cargo suddenly explodes & rips the plane into 2 parts!

WHAT THE ****????

No temp gauges, no warning, nothing - inside the cargo bay!

At 60km shallow reentry??

So, whatever the intention of this heating changes was - I cannot let a crew of 4 die this way.

Someone please tell me which parameters in the physics conf do I have to alter to bring the behaviour closer to 1.0.2?

Thanks!

Edited June 26, 2015 by TheDog
found cause - time warp

[Snark]

What exactly does the "flight event" log say when you press F3?

[TheDog]

From the log file:

[LOG 23:06:38.110] [00:09:29]: Clamp-O-Tron Docking Port Jr. exploded due to overheating.

[LOG 23:06:38.110] dockingPort3 Exploded!! - blast awesomeness: 0.5

So it is actually the docking port exploding due to overheating.

But again: inside a closed cargo bay? At 60km? at ~2300m/s???

This is not right for me - so anyone got an idea which physics parameters I can touch to revert to a more 1.0.2 style heating?

[rofltehcat]

You can probably play around with the stats in the servicebay stats (make copies of the part somewhere before editing it):

heatConductivity = 0.04

thermalMassModifier = 5.0

emissiveConstant = 0.95

MODULE

{

name = ModuleConductionMultiplier

modifiedConductionFactor = 0.001

convectionFluxThreshold = 500

}

I wonder what happens if you set the modifiedConductionFactor to 0 or 0.00000000001 or something like that and increase the convection threshold.

[TheDog]

OMG, found the cause...

Using time warp within the atmosphere makes the docking port overheat and explode within seconds!

Descending without any time warp -> zeor problem, no temp gauges, no heat warning, just a soft splash down.

How annoying - will file a bug report for this (in support - modded installs).

[Starwhip]

That definitely sounds like a bug if it is in fact the cause.

Can you replicate it?

[Empiro]

I've also encountered a similar issue during my ascent. I'm using FAR, so that may or may not have anything to do with it, but I definitely can get this if I use physical time warp, including once when I was outside the atmosphere (firing small engines that were nowhere near the port).

[jwenting]

OMG, found the cause...

Using time warp within the atmosphere makes the docking port overheat and explode within seconds!

Descending without any time warp -> zeor problem, no temp gauges, no heat warning, just a soft splash down.

How annoying - will file a bug report for this (in support - modded installs).

Experienced the same explosion in the stock LearStar 1A when attaching something to the docking port inside the bay. Thought to use it to launch some comsats for my remotetech network.

Difference: it exploded the moment I engaged the first stage engines, no time acceleration involved.

[FlipNascar]

I had something similar in atmosphere - after 21 minutes a battery exploded due to overheating while in atmospheric flight. It was in a cargo bay and should have been occluded. Haven't yet tried to replicate it though... Time warp was involved.

[Laie]

Also see this:

It's a bit long and winding for a bug report, but then again, it's actually fun to watch. If you only care about the cold hard facts, skip to about 2min. Instant overheat the moment the bay closes. I don't know if the part clipping is necessary... but then again, this is no clippy kraken, this clearly is overheating.

Edited June 26, 2015 by Laie

[Mic_n]

Be aware that something being occluded doesn't prevent it from heating. Parts can also heat up from heat being conducted from other parts.. The big spaceplane parts have a huge thermal mass and while they generate a lot of heat, they also radiate it pretty well. I haven't looked at the actual numbers, but I suspect that some of those parts - particularly ones inside bays - aren't able to radiate it away quite as well, so they build up conducted heat from the attached parts but don't really get rid of it very well. I've complained of the same thing happening to command pods and batteries in service and/or cargo bays.

With the new radiator parts and skin/core temperatures, the thermal mechanics are obviously still a work in progress. Hopefully the guys will have it sorted out shortly.. it seems better in 1.0.3 than it was previously, but still a bit of a problem. I'd suggest mucking about with radiators in the meantime, and try to avoid hooking straight up to parts that generate a lot of heat, maybe put some rads there to wick away some of the heat before it gets to those critical components.

[Empiro]

I think it's still likely to be an odd bug of sorts. The fact that it only happens when you physical time warp probably indicates that some heating constant isn't handled properly.

Does anyone know if closing the cargo bay also hides the part from the temperature gauges? For me, it's definitely the case that I don't see the gauge before it explodes, and none of the parts around it show the gauge.

[Mic_n]

Nope.. I've most certainly seen bars come up on objects inside bays (both cargo and service)

[jwenting]

I think it's still likely to be an odd bug of sorts. The fact that it only happens when you physical time warp probably indicates that some heating constant isn't handled properly.

it also happens when not in time acceleration, see my previous post. Docking ports blowing up the moment you start the engines on the launch pad, but only if there's something attached to them.

Starting to think vibration from the engines overstresses the docking port when there's mass suspended from it while in a high-g environment, it breaks and the game engine falsely reports that as overheating (iow, wrong message).

[Mic_n]

it also happens when not in time acceleration, see my previous post. Docking ports blowing up the moment you start the engines on the launch pad, but only if there's something attached to them.

Starting to think vibration from the engines overstresses the docking port when there's mass suspended from it while in a high-g environment, it breaks and the game engine falsely reports that as overheating (iow, wrong message).

Out of curiosity, are you strutting your payload inside the cargo bay? That should reduce (or eliminate) those stresses. Also, launch clamps to be able to fire up the rockets without moving your craft. If it still happens, that's one less possibility. Also, try alt-f12 and check out the 'show thermal debug' option in there somewhere, you can check the figures live.. but if it happens straight away, you might not have the chance.

[jwenting]

no, it wasn't strutted. Good idea, if it's indeed mechanical stresses that are incorrectly reported.

Thermal overlay won't do any good, it explodes 1-2 seconds at most after engaging the engines, while still supported by launch clamps.

[rmzalbar]

no, it wasn't strutted. Good idea, if it's indeed mechanical stresses that are incorrectly reported.

Thermal overlay won't do any good, it explodes 1-2 seconds at most after engaging the engines, while still supported by launch clamps.

I have a surface-to-LKO space station module lifter. I had my payload module assembly attached via docking ports under a long aero fairing.

At some point between MECO and circulization, the docking port attached to the nose of the lifter would overheat and explode, whether or not I had ejected the aero shell. Monitoring heat in debug showed a normal amount of heat in the ports (about 210) and normal heat flow through them (-65.) However, I happened to catch it just before it exploded. The heat suddenly dropped to zero, then cycled rapidly between 0 and over 4000 for about 1 second before it blew.

The way it cycled rapidly between 0 and 4000+ like that has to be a bug, as it's way outside the normal range. It's not the heat creep you get when you are adding heat faster than it can escape.

My time scale was 1 at that point.

I fixed the problem by removing the exploding port in the VAB, and attaching the payload port directly to the nose of my lifter. Still decouples just fine, so it was redundant anyway.