parts disconnecting and drifting away

[Michel Bartolone]

I've run into a strange issue, and I have not seen any threads that seem to match this symptom. I build a station using tanker ships I've been using for quite a while. Everything looks fine. Very recently (in the last week?) my stations start shedding parts. I'm not talking about falling apart due to the kraken. Example: two fuel tankers, docked to a central core, one other ship docked with some kerbals inside. One kerbal goes EVA to attach some struts, or something similar. Everything seems fine at that point. I have the kerbal board the ship. Everything seems fine so far. No shaking, vibration etc. Go to transfer some fuel, and I can't. I look carefully, and the tanker I just got done adding struts to, to make it stronger and more kraken-proof, has separated (gently) at a point farther from the core, than the most recent strut attachment, and the back half of that ship is now just drifting away. It isn't at a stack separator, or decoupler, it is at the junction between two tanks, connected in the VAB, with auto-strut, and ridged attachment turned on. I've even tried reinforcing some of those joins in the VAB, with multiple struts, and it still happens. It is as if you used a glue to join them together, and the glue loses it's adhesive properties in the cold of space. 
 

Has anyone else seen this? Is this something that is a known bug (that I was not able to find) and maybe has been patched in 1.4.5? (I'm running 1.4.4.)

[4x4cheesecake]

Very strange issue, never hear of it.

Does your ingame flight protocoll (hit F3) show any events? Any events in your logs, like joints breaking?

[Gargamel]

Interesting. 

There is a bug, caused by a variety of mods, that will have various parts shift their locations upon loading the ship.  The shifting can be quite severe at times, with parts floating next to the craft, but technically still attached.   But if the part is truly separated from the main vessel, then you should be able to tab over onto it, even if it is debris.  Hit [ or ] to see if you can tab to control the loose part/vessel.   If you can, then it truly is a being treated as a separate vessel by the game, if you can't, then it is still attached, and something very wonky is going on. 

If you're using KAS/KIS to do your strutting, I've had a similar issue where I accidentally clicked on the wrong part of the ship and didn't notice that I had cut my off a part of the station.   There maybe something you are clicking on, repeatedly, and by accident, that is cutting away parts. 

Can you recreate this with a new ship of similar design or is it this vessel only?

And along with cheese's suggestion of checking the logs, a few pics wouldn't hurt either. 

[Michel Bartolone]

17 hours ago, 4x4cheesecake said:

Very strange issue, never hear of it.

Does your ingame flight protocoll (hit F3) show any events? Any events in your logs, like joints breaking?

I'll give that a try, and get some screen shots as well. Probably in the next day or two. I did notice an additional one, very similar, with a new vessel. I was in reentry, I had a standard mk3 command pod with a 2.5m heat shield, then a decoupler below that. When I staged the decoupler, the heat shield came lose as well. I am using KIS/KAS.

Definitely _not_ still attached and just looking detached...I was not able to transfer fuel from the disconnected part to other parts not disconnected, and I was able to switch to the disconnected parts as a separate vessel. And now, things like heat shields are disconnecting from items they are directly attached to, when a stack decoupler on the other side of the heat shield is staged.

Edited August 15, 2018 by Michel Bartolone
additional info

[Michel Bartolone]

I was able to reproduce the heat shield disconnection. I don't know why this is happening now (when it hasn't previously) but the stack separator crashed into the heat shield, causing a "structural failure on linkage between Heath Shield (2.5m) AND MK1-3 Command Pod". It will take a while for me to reproduce the other (original failure) as I will have to rebuild a station to test it on.

 

[Gargamel]

7 hours ago, Michel Bartolone said:

I was able to reproduce the heat shield disconnection. I don't know why this is happening now (when it hasn't previously) but the stack separator crashed into the heat shield, causing a "structural failure on linkage between Heath Shield (2.5m) AND MK1-3 Command Pod".

That's the atmosphere pushing the decoupler back into the heat shield.  If you are ditching a service module prior to reentry, do it just before entering the atmosphere.   Even better, use sepatrons to push it away from the command module.    If you don't want to use propulsion to separate the craft, then turn sideways, stage, then turn back to retrograde.    That will 'push' the service module to the side and out of the way.    Be aware though of the extra EC this extra SAS maneuvering will require.  If your batteries are on the service module, you won't have a lot of left over juice to play with. 

[JoE Smash]

On 8/14/2018 at 12:49 PM, Michel Bartolone said:

I've run into a strange issue, and I have not seen any threads that seem to match this symptom. I build a station using tanker ships I've been using for quite a while. Everything looks fine. Very recently (in the last week?) my stations start shedding parts. I'm not talking about falling apart due to the kraken. Example: two fuel tankers, docked to a central core, one other ship docked with some kerbals inside. One kerbal goes EVA to attach some struts, or something similar. Everything seems fine at that point. I have the kerbal board the ship. Everything seems fine so far. No shaking, vibration etc. Go to transfer some fuel, and I can't. I look carefully, and the tanker I just got done adding struts to, to make it stronger and more kraken-proof, has separated (gently) at a point farther from the core, than the most recent strut attachment, and the back half of that ship is now just drifting away. It isn't at a stack separator, or decoupler, it is at the junction between two tanks, connected in the VAB, with auto-strut, and ridged attachment turned on. I've even tried reinforcing some of those joins in the VAB, with multiple struts, and it still happens. It is as if you used a glue to join them together, and the glue loses it's adhesive properties in the cold of space. 
 

Has anyone else seen this? Is this something that is a known bug (that I was not able to find) and maybe has been patched in 1.4.5? (I'm running 1.4.4.)

I don't use rigid attachments, but I do use auto struts....but I have never seen this before.

Are you using other "strut" mods on top of using autostruts in game? I ask because you are also trying to attach EVA struts too?

I'm wondering if you are "overdoing" it. Autostruts are usually more than sufficient to keep a ship together....

You are not also using Kerbal Joint Reinforcement and/or Quantum struts on top of auto struts in game are you?

I believe those strut mods were developed before in game autostruts were included. I'm not sure they are necessary if you are already autostrutting in the game.

Also try autostruts WITHOUT also using rigid attachments....

Rigid attachments can make the joint between two parts brittle and more prone to breakage....

Again I would try JUST auto strutting....to like the grandparent part for general ship stability...