SV first stage had 5 engines, vs 33 on the Starship's booster. Which I think answers your question :)
I don't know about other metrics for comparing engine efficiency. But the design requirements seem quite different here - they have to be restartable (not something the F1 engines on the SV had to worry about), probably more steerable, and able to throttle down to quite low power for landing. And presumably the fact that there's so many in an array also imposes its own constraints on the design.
> > > Is 2x thrust accomplished by scaling # of engines, or are the engines 'more-thrustful' per unit because of engineering advances?
> > SV first stage had 5 engines, vs 33 on the Starship's booster. Which I think answers your question :)
> it doesnt, please eLI5
I kinda suspect bad faith/trolling, but if not... 6.5 times the number of engines for twice the thrust means that you are getting less thrust per engine.
No trolling, but one of the the things I like to promote on HN is for people to ELI5 as much as possible, given the fact that our knowledge will evaporate over time... so I want people to, as much as possible, divulge as much as one can before they kick the can...
Yah, I just though this wasn't really subject matter expertise. It's not quite ELI"5", but I thought reasoning using ratios would be universal/intuitive.
Having a whole bunch of engines means loosing a few at launch won't end in disaster. That means you can pursue more high-risk, high-performance engine designs.
Starship at this point is mostly a shell. Internal human grade components aren't there yet. We have no idea what the final cost will be. But doesn't matter since NASA is the one paying.
> We have no idea what the final cost will be. But doesn't matter since NASA is the one paying.
The HLS contract SpaceX has gotten from NASA is a fixed-fee contract (like most contracts NASA gives out these days), so the final cost absolutely matters to SpaceX's bottom line. Anything they spend beyond the contracted amount they'll have to come up with themselves. A good example of this is Boeing, which is now booking losses on the Starliner program every quarter because it has gone over time and budget.
What? This makes zero sense. The cost to create a crew capsule is extremely well understood because they've been made countless times before. Also to imply the cost of that would put any dent whatsoever into the 5b vs 50b comparison is ridiculous. The cost of adding a crew capsule is a rounding error on total cost.
Actually we do know what NASA will be paying. Its all in the public contract. And its fixed cost, so it will not cost NASA more, no matter how often it blows up.
That doesn't give us details about how much it will cost SpaceX but its good information.
