Craft stuck when decoupling and separating multiple craft

[Korbat]

Hi,

I've tried all kinds off different things and as a final resort i come to you my fellow kerbalnauts.

I've constructed a small comms sat to launch for my remotetech network. I saved it as subassembly and then constructed my booster with enough delta v and then attached three satellites to the interstage nodes inside the fairing.

Now whenever i try to test the decoupling mechanism the following happens: satellite separates from booster, physics freak out, satellite is stuck floating mid air. At this point my controlled vessel is still the booster (root part is probe core on booster). However, if I switch to the detached satellite the game doesn't respond to my inputs anymore and it crashes.

I recreated the issue and recorded it so you guys can see what i'm on about here. I just did it with a single satellite.

https://youtu.be/1dPNdv4_9bA

 

I really don't get what's going on here. I also tried it re-rooting the part from the probe core on the booster to the core of the satellite i'm detaching. And that seems to work. But i don't remember this being a bug in the game or it might be cause by some mods. But all the mods i'm using I use for a very long time and never had this problem. Does this mean i have to manually click the satellite i'm about to deploy, then press 'control from here' and then detach the satellite?

 

Hope you guys can help a brother out,

Fly safe

btw how do i add a log file to my forum post without just pasting the whole page in here?

EDIT: https://drive.google.com/file/d/1-mPQAcyMVnawKMVzpwnrNT5X-84e70G3/view?usp=sharing

Mod list is also in there

Edited February 20, 2021 by Korbat

[paul_c]

What kind of core does the satellite have? Does it have comms and battery power at least? How is it detaching - eg TD12 decoupler firing? Something else? (The video doesn't show it clearly enough, but its nice to have!)

[Korbat]

It's the OKTO2 probe core in both the satellite and the upper stage of the rocket. I have sufficient power and comms for the crafts. It's using a TS-06 stack separator. Thanks for your reply

[Korbat]

"Does this mean i have to manually click the satellite i'm about to deploy, then press 'control from here' and then detach the satellite? "

I tried this btw, does not work for me either. So i think there's maybe a problem with using multiple probe cores on the same craft? I've had it before with a rover i tried to deploy on the mun. It was attached to a lander with a cubic strut and decoupler and the physics on that thing froze as well when i tried to decouple it.
I fixed it by replacing the decoupler and cubic strut but this method doesnt seem to work on my current rocket. After all, this stuff just has to work. In previous saves i launched rockets with 8 satellites on them and didnt have any problem with decoupling and physics freezing.

 

Really hope someone can help me out. This game means so much to me with the mods i currently have but it's pretty much unplayable if i can't even put a few sats in orbit

 

[Korbat]

I tried using docking ports instead of decouplers or stack separators but i'm still experiencing the same issue. The craft separates, physics on the separated craft immediately freeze up and when i switch to it the game freezes and I have no control anymore. Which then forces me to close down the game using the task manager.

The video below maybe is a bit more clear on what exactly happens than the previous one

https://youtu.be/4UI-1KDz6cM

[paul_c]

This is beyond my experience with KSP but you should definitely be able to design/build/launch a vehicle with several OCTO controllers and then separate them, and so long as each has electrical power/comms, it would be controllable. Of course for attitude control you'll need one of: reaction wheels, RCS, gimballing engine running; and it doesn't necessarily need an engine/fuel but if it does, it can go places or change its orbit etc (its possible to launch into an orbit, or leave on the surface, an 'unpowered' thing if you so chose).

The way I normally do it is ensure each has solar panels/batteries/small engine/fuel tank/aerial, ie its a fully functioning craft, then plan quite thoroughly the order in which they will leave the main ship in space. Of course, if a fairing was used for the flight uphill, this would be blown apart before any deployment.

Decoupler, docking port, stack separator - shouldn't make any difference.

I can only suggest, you design from a clean sheet, a very basic rocket which has the bare minimum eg some rocket stuff underneath, and 2x OCTO controllers (and maybe the basics of other parts as above) separated by a stack separator/decoupler. I am wondering if there's a corruption in the files of your existing craft; or a special/non-standard part in there somewhere?

[Korbat]

Thanks for your reply,

Did you take a look at the videos i sent? Because then you can see it's the game physics crahsing and freezing up instead of rocket design. I know how to build and design rockets in ksp. I've played since day one when the game released in alpha. So i know a fair bit about what i can't and cannot do with rocket design in this game. It's just that there's clearly a bug going on here and was looking for some help with that. The physics are freezing and from my personal experience it's nothing to do with the rocket design. To me it seems that one of the mods is not working correctly like it should.

Ofcourse there's non standard parts in here, hence i made this post in the modded technical help section of the forums. But its very minimal, only a few remotetech antenna's and a couple engines from Near Future packs. These are two mods that have been around for a very long time and have been very stable over the past few years. That's the reason why i don't understand what's going on here.

Since i'm running like 35 mods it's not easy to just intstall one by one and check every mod on integrity, so was hoping someone has had the same problem but couldnt find it anywhere.

[Korbat]

 

I'm trying to troubleshoot building the satellite part by part onto the booster. So far all good. Got a probe core, remotetech antenna and a small fuel tank on there right now. Will update this with my progress

[Korbat]

Might have found the problem here. I hope that someone could please confirm this.

It remade the entire craft, part by part reconstructing the satellite. Testing on the launch pad everytime I added a part.

https://youtu.be/lo8iGNEFIxQ

In this video you can see that all the same parts as the very first video are on there, only this time i did not clip them into each other to make it look good.
It seems to be that clipping to many parts into such a small space or satellite like that makes the physics of the game freeze and therefore crash the whole game.

 

Anyone can confirm this?
Thanks in advance

Edited February 21, 2021 by Korbat

[Korbat]

Allright, after testing a few more things with the satellite with all the clipped parts. Apperantly the small Cubic-Family Strut seems to be the problem. If you use the strut to attach multiple craft together and fix the strut on the decoupler or separator, the physics on the to be separated craft freeze.
In the video below the craft is built without the strut and it is working perfectly fine. However if I use the strut the problem is there again.
 

Now, for this mission i can work my way around and just manually create some space between the separator and the satellite. However for bigger craft i pretty much always used to use these small cubic-family struts to space out objects from eachother. I got so far to finding the faulty part, only thing i'm not capable of doing is fixing this problem. So I really hope there's anyone on this forum who might have an idea on what to do with this bug/issue.

[Motokid600]

Wow. I cant believe I found this. Months later Im having this issue as well and go figure im using the hell out of that cubic strut attached to decouplers for this exact reason. Trying to launch multiple sats at once. Pulling my hair out trying to fix it. If its honestly just the damn cubic strut causing the issue then... oof..... Ill try removing them from my design and report back.

Edit: Yeah. Removing the cubic strut fixed it. Sorry I know this is months later. But @Korbat do you happen to recall if you were using restock at the time? That's my first suspect. But at this point im so burnt out on troubleshooting I think im just going to avoid using the cubic strut on decouplers. May have something to do with it being a part with no mass.

Edit2: Nevermind saw the list in the OP. Yeah I see both ReStock and ReStock Plus of which I also have.

Edited April 11, 2021 by Motokid600