

U.S. Needs to Weigh Rocket Engine Options, General Says - anigbrowl
http://www.bloomberg.com/news/2014-07-16/u-s-needs-to-weigh-rocket-engine-options-general-says.html

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ejr
Could anyone with knowledge about engines explain why Russians always seem to
prefer multi-nozzle designs? Is there some inherent advantage in redundancy,
cost or some other factor?

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apkessl1
As a rocket combustion chamber grows larger, so does the chance of a
destructive combustion instability. The Russian solution was to split that up
into smaller chambers resulting in multiple nozzles. It was a practical
solution to a challenging engineering problem.

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avmich
Agree. Decision to make engines multi-chambered had to take into account the
overall situation existing at the moment.

For example, when in 1954 Energomash was designing RD-107, it had to make a
decision which would allow to make engine soon - and they couldn't make
single-chamber engine for the thrust required. So they went for multi-chamber
design, since they didn't have time to do it differently.

In "Осуществление мечты" an engine professional, who worked in Energomash,
mentioned that when Energomash was choosing 4-chamber design for RD-170, there
were two groups of specialists defending different approaches. One group -
which had experience with RD-107 (multi-chamber engine) and RD-270 (biggest
one-chamber Energomash engine) - advocated single-chamber design. Another
group - which had experience with RD-253 (single-chamber) and engines for
Kosmos launcher - advocated multi-chamber design. The decision was influenced
by having the instrumentation necessary to conduct testing of smaller chambers
independently.

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Aqueous
Is Musk even interested in bidding for military contracts? It seems like that
runs contrary to his vision of bringing humans to space, and his broader
vision of space exploration for the sole purpose of benefiting (and prolonging
the life of) humanity.

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Zancarius
I don't see why it would conflict. He gets to prove his rockets function well
enough for DoD needs, and SpaceX gets more money/experience.

AFAIK, following the retirement of the shuttles, the US no longer has a heavy
lift capability. Looking to indigenous companies for filling that void is
probably a medium/long term goal.

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Sanddancer
The US still has heavy lift capability from the Delta IV, which will be used
for the first few launches of the Orion system. It isn't human rated, though,
with that replacement coming in a few years with the Space Launch System/

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salem
It's good to have options. I'm surprised it took them this long to realize it.

