>>11023601>Why would you need to mass produce so many engines if your vehicle is supposed to be as reusable as you say it is?I think the break-down comes to this...
>Economies of scaleSpaceX wants to reduce the cost of each critical part as much as possible. For complex and natural expensive parts like the engines, this requires said parts to be made in large batches. This can be met by some other points.
>SpaceX needs lots of engines per rocketEach BFR stack requires far more engines than even an entire year's worth of expendable rockets. An Ariane V needs about 4 engines (I'm counting the SRBs) per rocket, and if there's 10 guaranteed launches per year then Ariane needs 40 engines per year. A single BFR (at least in it's current iteration) needs 43 engines total. And that's ignoring larger version of BFR.
>Spare partsThings will get broken and worn, and thus need to be replaced. Replacing a part of the pump assembly on a couple of engines is still cheaper than replacing the whole rocket. Plus, SpaceX isn't going to get reusability done perfectly on the first couple of BFRs, things are going to break as they figure out the finer points.
>More BFRsSpaceX isn't going to settle on just having one BFR. Their goal is to have a fleet of them. The idea being that having lots of reusable rockets would allow for more frequent launches which not only means more profits for the company, but also less cost per launch which means that even more potential customers can afford a ride on BFR and you don't need a degree in economics to know that's a good thing.
Also, nice uncalled accusation of SpaceX lying. If you're going to make claims like that, then back them up with facts.
