Conventionally, rockets have used multiple stages, each specialized for flight through Earth’s atmosphere or the vacuum of space respectively.
SpaceX appears to be streamlining the process with one engine design, according to Ars Technica’s analysis of Musk’s tweet. The approach will have some key advantages, according to Ars: it could take significantly less time and money to develop and test the rockets.
What About Mars?
So what about Mars? SpaceX touted Starship as the ultimate passenger vehicle that could ferry people all the way to the Red Planet. So why all the talk about going to the Moon?