H&H Design of Liquid Propellant Rocket Engines (the AIAA doc, not
SP125), Sect 2.4, pp 37
"However, relative to the other two cycles, the staged combustion
cycle has the highest performance, but it is more complex, more
difficult to develop, and heavier."
Ed Kelleher
At 03:48 PM 12/29/2015, David Gregory wrote:
It was stated that GG engines are lighter than alternatives. At a given chamber pressure, that's not the case.
> On Dec 29, 2015, at 12:40 PM, David Weinshenker <daze39@xxxxxxxxxxxxx> wrote:
>
>> On 12/29/2015 12:02 PM, David Gregory wrote:
>> There is nothing magical about the GG cycle that makes it lighter.
>
> No, there's nothing "magic" about gas generator cycles - they're a
> simple, effective solution. There's something a bit "demonic" about
> staged combustion cycles (from the engine development point of view),
> though; it's much harder to develop such an engine incrementally: you
> sort of have to get everything working at once in order to test-run
> anything.
>
> I heard that a number of SSME prototypes were consumed in the
> process of discovering a safe startup sequence... it wouldn't
> surprise me if there were similar experiences "over there",
> during the initial development of the RD-180.
>
> -dave w
>
>