After several flights to Mun, Minmus, a successful mission to Duna (and a rescue mission and a rescue-rescue-mission), I decided to build bigger. 1500 tons on the launchpad. Curse you mainsails, I say: It all went fine until i reached the upper athmosphere, then the monstosity started to rotate slowly without me being able to stop it. So what, it still went up as it should, just steering was harder. Then at some point, the mainsale stage decided to push itself through the upper stages, resulting in a big mess. I don't know how, but Jeb magically survived this and splashed down with a single parachute into the ocean. After a few more tries, replacing/moving weaker parts and a LOT of space ducttape, I finally got it into orbit. The weak spots were control parts and docking ports. Those cant handle too much mainsail powah. The monster is still in Kerbin orbit as I forgot to man the science module I'm just preparing a supply mission for it, with additional modules, so it can head to Jool and testland/crash those 6 probes...