satorarepo

Wow, you even replicated the rocket! Thanks a lot, I managed to make it launch very stably with struts and a larger decoupler (plus moar boosters, of course!).

Thanks for all the answers. Let me clarify a bit about my weird design, though. I know this rocket is way too tall and perhaps lacking some delta V. This screenshot was taken after stripping out the radial SRBs I was using to make the unstability more evident (it was also a kind of experiment with super tall rockets). I did not even try to fire the engines with that thing I know, this setup was just for experimenting (and desperately try for more stability). I'm a bit ignorant about reaction wheels. So in principle they should be just below the command module? It is a skipper. Concerning struts, I was used to adding them to radial tanks and SRBs... where exactly should I put them in a ship like this? The top stage is indeed oversize, but that's because this ship is supposed to refuel a stranded one. Maybe there's a more clever way to do that? Yeah, I'm concerned with the size too. Same answers as to @CBase though

I was trying this very tall rocket build and it became extremly unstable, to the point of wobbling on the launch pad even before launching. In fact, it moved so much I could only speed up the game up to 4x. In the picture you can see that the modules seem to get disconected from each other. What causes this and how can I prevent it? Thanks!