Since the command module decided to fall off my Kethane tanker but I realised I still had a remote guidance unit on board from before it was adapted from being a mobile Kethane miner so I decided to send it on a 1 way trip to Eve for practice. Then I sent up another Kethane tanker to replace the broken one. But once it landed on the Mun and got fueled up it refused the lift off, engines on full it was just sitting there on the surface and I know that its got enough power to lift off as it's done it before.