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From: larson@unix.SRI.COM (Alan Larson)
Newsgroups: sci.space.shuttle
Subject: Re: 104% on shuttle launch
Message-ID: <30087@sri-unix.SRI.COM>
Date: 30 Apr 89 09:54:38 GMT
References: <883@sactoh0.UUCP> <9130003@hpwrce.HP.COM>
Reply-To: larson@unix.sri.com (Alan Larson)
Organization: SRI, Menlo Park, CA.
Lines: 34

Jeff Boerio wrote:

>My personal opinion, and something that I certainly don't know as fact, would
>be that the engines used were originally expected to operate at a level X,
>or 100%.  But, the production engines actually operate at X+4%, or 104%.
>
>That's what seems a little better to me, but again, I could be absolutely
>wrong.


In article <9130003@hpwrce.HP.COM> howeird@hpwrce.HP.COM (Howard Stateman) write
s:

>You're absolutely wrong, Jeff.   :-)
>
>Seriously, when I read your response I thought you were joking, till I
>saw this last line.
>
>Every engine I have ever seen has had the ability to be pushed beyond its
>limits. It's why they have a red line on the tachometer in your average
>sports car (Camaro, Firebird, etc). I find it hard to believe that the
>folks at NASA have build an engine which only operates at peak efficiency.
>mostly because there is no such thing.


Howard,

  Jeff is right.

  By the way, peak efficiency is not normally the 100% power point
on an engine.  Peak power and peak efficiency are different.


        Alan