Right because HN is a tutorial? Nobody here can understand much without detailed explanations. The purpose is, so folks can look up delta-v and start to unders

Right because HN is a tutorial? Nobody here can understand much without detailed explanations. The purpose is, so folks can look up delta-v and start to understand. It's not necessary to recapitulate everything on the web in a post. For instance I google 'orbital mechanics delta v' and the whole story is right there for the taking.