I've been playing KSP for a few months, so I am not a total noob. Today I have been trying to perform manned missions to Moho and Jool (Tylo specifically), but every time I have tried to perform my transfer out of a Kerbin orbit, I find myself plummeting into Kerbin every time. By the way, I have been to Jool about a dozen times (and Moho twice), so It's not like I have no idea what I am doing, but obviously something is going wrong this time. For further information, I have tried performing the transfers with Mechjeb with no success and I have tried performing them manually, according to phase angles given by the ksp.olex.biz calculator, with the same results (crash and burn). I'm not sure what I am doing wrong because, like I have mentioned, I have performed this same burn a dozen times with no problems. There is probably a simple explanation for this, but I have given up at this point.