So, exploring Minmus in career mode. I built a little 1-kerbal lander. It's actually autonomous, with a seat, so a scientist or engineer can ride it. Naturally, it used monopropellant instead of rocket fuel. So, after a round trip between Minmus station and the surface I only had enough monopropellant fit either the station out the lander. Thus I resolved to build a tanker. Now I already had a ship whose sole purpose was to transfer crew between KSC and Minmus station, so I decided to use the same rocket. I took the weight of the crewed section and built a tanker of the same mass. Due to my current position on the tech tree, it was a scaffold tower bristling with spherical tanks. I don't remember how many, but they held almost 4000 units. I put it on the rocket and hit launch. The launchpad and craft loaded. Physics switched on. The monopropellant tower exploded. It didn't fall apart, it exploded. All that remained was a docking light and the aerodynamic fairing, which fell off the rocket. So I added some struts, tried again and reached space. Then I separated the tanker from the final rocket stage. It exploded. Nothing remained, no debris except the dropped stage.
