Re: Engine design breakthrough

John Carmack wrote:

> At 09:28 AM 4/17/2004 -0700, you wrote:
>
>> [email protected] wrote:
>>
>>> Breakthrough in long lived rocket engines:
>>> http://www.spacedaily.com/news/rocketscience-04j.html
>>
>>
>> Yawn.  Tell them to call me when they hit 500 runs.  We've *never* 
>> had to polish a chamber.
>>
>> Doug, Rocket Plumber
>
>
> To be fair, a 500,000 lbf 3000 psi hydrogen engine has a bit harsher 
> conditions than a 600 lbf 150 psi alcohol motor,

That's what I was thinking too; but then you get into questions about 
whether NASA had to actually build a 3000 psi hydrogen engine in the 
first place (i.e. no); and that's where Henry's point becomes very, 
very, very valid.

And there's a further point, that the article mentions that this 
technology might be needed for orbital taxis, (but then never mentions 
why you would want the high chamber pressure that helps cause these 
problems in such an engine anyway- you very probably don't, just running 
a few hundred psi is probably fine); whilst implying this kind of 
problem is inevitable because the Shuttle has it :-)

> John Carmack