They are currently developing the methalox Raptor [1] engine that is planned to have 2300kN sealevel thrust. That would be more than six times powerful than the

They are currently developing the methalox Raptor [1] engine that is planned to have 2300kN sealevel thrust. That would be more than six times powerful than the Merlin 1D+s in current Falcon 9. That would be solidly in the heavy lift rocket engine category, specifically as they intend to group them like they group engines in Falcon 9. [1]: https://en.wikipedia.org/wiki/Raptor_(rocket_engine) https://en.wikipedia.org/wiki/Raptor_(rocket_engine)