My ship always falls apart the moment I put it on the launchpad. I use the big boosters and heavy declouplers from Project Firelark, and attach the decouplers to normal liquid fuel tanks. When I put it on the pad the fuel tanks attached to the decouplers sever from the rest of the ship immediately, and the boosters fall away too. This may just be an incompatibility with the 0.13.2 update, but I\'m not sure.