In article . com,
says...

On 2017-10-02 05:58, Jeff Findley wrote:
Carbon fiber tanks will be something new for SpaceX, so it's a risk.
The question is, how big of a risk?

My concern with the 1 big tank design is that for a long duration
flight, a failure of the one tank is sayonara for everyone.

You can't eliminate every single point of failure. But you add
redundancy where it makes sense.

Howewer, in commercial aviation, the reverse is now true. The 777 has
won over the 747 mainly because owning a plane with 2 engines costs a
lot less than one with 4 (as engines are costly to buy and maintain).

Only because today's turbofans are far more reliable than they used to
be. It wasn't easy to certify the first twin turbojet for ocean
overflights.

I wonder if rockets will also eventually adopt the "fewer but bigger
engines" mentality to cut maintenance costs.

I believe that Raptor is bigger than Merlin in terms of thrust.

more existing engines on the next design than to have to design and
build new engines, then both Musk and Bezos will do so, even if it
complicates the plumbing, structure, control systems, and etc.

But again, once you have more then 3 engines, does using 3 5 or 9 make
things that far more complex? Isn't there a lot of "copy/paste" done on
the engine mount designs once you are beyond 3 engines ?

Depends on the details. But in general more engines means more
plumbing, more valves, and etc.

Jeff
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