They are making an engine they call Raptor for their planned giant rocket: https://en.wikipedia.org/wiki/Raptor_%28rocket_engine%29 https://en.wikipedia.org/wik

They are making an engine they call Raptor for their planned giant rocket: https://en.wikipedia.org/wiki/Raptor_%28rocket_engine%29 https://en.wikipedia.org/wiki/Raptor_%28rocket_engine%29 It is not a swappable substitute for the Russian ones, because it uses a different kind of fuel and probably for lots of more complicated reasons.