The current tool is very difficult to use when planning interplanetary transfers. What I propose is something that looks exactly like what we have now, but instead of being anchored to the orbit, it should be a free floating tool like the navball. You would create a maneuver node exactly like you do now. Choose a place in the orbit, click it, choose create node. Once it is created, things change a lot. An icon showing the node position is placed on the orbit and a tool appears on screen nea