Failure to undock 2 ports that are currently mated.

[_Zee]

My current project is building a low orbit space station. It is in the very earliest stages, and I've run into a problem.

I'm launching the pieces up one by one, and then using a "tug boat" to pick them off the launch craft, and then place the piece onto the station. I got the piece into place, but now I can't get the tug boat to disconnect from the piece that I've added to the station. If I try to disconnect the tub boat+solar array from the station, then it works just fine. But it won't allow me to simply remove the tug boat from the solar array. Pic included. Thanks for your help.

[TBryson2]

I too have issues with undocking and a similar situation as yours. I did notice that if I undock the part I just docked, THEN and only then can I undock my "tug" from that part. I cannot undock the tug from the "part" I just docked. Seems there is something hanging it up.

I'm hoping that someone will answer this post eventually with a suggestion.

TB

[CaptainKipard]

There is no solution. It's a known bug. You'll have to do what TBryson2 said. I've had this problem too and this is the only way to solve it.

[DMagic]

Yeah, this tug thing seems to come up a lot recently. It seems to have to do with docking parts that don't have any probe core or command pod, to each other. Even though the station as a whole has the cupolas, if the segment that you are docking doesn't have any control points it can cause this issue.

The game seems to maintain some understanding of how multipart crafts like this are put together. So that segment without a probe core is still, on some level, considered separately from the vessel as a whole (the parts are all listed together under the same vessel in the persistence file, but there are still some traces of it being separate).

Most of the time your solution of undocking one part, then the other works (you can sometimes push the part into place with the tug without actually docking). When it doesn't, or if you just want to learn how to fix it, there is a way.

This thread describes a few scenarios for how things look in the persistence file and how to fix them.

http://forum.kerbalspaceprogram.com/showthread.php/35777-Can-t-Undock-Bug

It is fixable, but it's not exactly straightforward, and it requires some knowledge of how to edit the persistence file (you can also edit the quicksave file). Just make backups before you try anything.

Edit: It seems Kipard and I are trolling the How-To threads at the same time. The method linked above does work, at least for me and the thread starter, but yeah, it's usually easiest to try working around the issue.

[CaptainKipard]

Hey I'm not a troll. I'm genuinely trying to help the newbies. No one held my hand when i first started. But I know less than you though.

[DMagic]

I know, it was meant in jest, since we twice posted at just about the same time in different threads.