Re: Could Falcon 9 compete with the Stick?

Pat Flannery <flanner@xxxxxxxxxx> wrote in news:11i1d25c5e3aie6
@corp.supernews.com:

>
>
> Damon Hill wrote:
>
>>Right now we must wait to see if this egg successfully hatches
>>and grows up, let alone multiply into a 27-engine behemoth.
>>Got my fingers crossed that it doesn't turn into a flightless
>>turkey.
>>
>>
>
> I think anything beyond 10 engines max inspushing it in the reliability
> department; if they do get a 27 engine design, they have gone very close
> to N-1 territory.
> The advantage would be that you could lose a engine or two (maybe even
> 4) and still reach orbit; the downside is that you are counting on
> benign shutdowns of faulty engines, so you don't get a cascade failure
> if one motor explodes.

Egg-xactly! Redundancy buys you only so much insurance; after that,
increased complexity leads to more risk, and more complicated failure
chains. Bet they'll have fun with all the propellant manifolding, too.

I hope they've paid attention to soft failure modes, so the
redundancy >can< pay off. SpaceX will be prudent to take measured
steps up the complexity chain, so they can know how to take the
additional risks.

This doesn't compare perfectly with the R-7 family, which is really
just five engines with a lot of combustion chambers and nozzles,
plus verniers fed off the turbopump.

--Damon
.

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