According to the wikipedia article ( https://en.wikipedia.org/wiki/Prometheus_(rocket_engine) ), they're aiming for 3-5 reuses, which I believe is significantly fewer than SpaceX's Falcon 9 engine, Merlin. But maybe they'll get more in practice.
It's a methalox/methane-oxygen engine, like SpaceX's Raptor, as opposed to RP-1 kerosene, like Merlin. One nice aspect of this is that methalox doesn't deposit so much soot on the inside of the engine, so reuse should be simpler (this is one of the reasons for SpaceX's newer Raptor engines also using methalox).
It's got an open gas generator cycle, which means that it's likely less efficient than SpaceX's full-flow staged combustion Raptors, since it means it loses a few percent of its fuel to just running the turbopumps and the exhaust spitting off the side, rather than than heading down into the combustion chamber.
It sounds like it's much cheaper to build vs. their last generation of engine, but we'll see how it ends up in practice.
Getting something like this working is impressive, but who knows if it will end up being competitive, SpaceX is still iterating really quickly. Not an expert, but the design feels a little dated already, in comparison in comparison to Raptor, and Raptor is already flying.
It's a methalox/methane-oxygen engine, like SpaceX's Raptor, as opposed to RP-1 kerosene, like Merlin. One nice aspect of this is that methalox doesn't deposit so much soot on the inside of the engine, so reuse should be simpler (this is one of the reasons for SpaceX's newer Raptor engines also using methalox).
It's got an open gas generator cycle, which means that it's likely less efficient than SpaceX's full-flow staged combustion Raptors, since it means it loses a few percent of its fuel to just running the turbopumps and the exhaust spitting off the side, rather than than heading down into the combustion chamber.
It sounds like it's much cheaper to build vs. their last generation of engine, but we'll see how it ends up in practice.
Getting something like this working is impressive, but who knows if it will end up being competitive, SpaceX is still iterating really quickly. Not an expert, but the design feels a little dated already, in comparison in comparison to Raptor, and Raptor is already flying.