Interplanetary transfer burns can be tricky, especially if the vessel has a low TWR (as is often the case when using nuclear or ion engines). Manouver nodes assume instantaneous burns, so if your vessel has to do a substantially long burn to escape they become inaccurate. One of the techniques to minimize that effect is to split up the single big burn into a succession of smaller burns (sometimes called "periapsis kicking"), but that introduces its own problems: - The time taken completing