Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cs.utexas.edu!sun-barr!newstop!texsun!convex!mozart!dodson
From: dodson@mozart.uucp (Dave Dodson)
Newsgroups: sci.space.shuttle
Subject: Re: Improving main engine power
Message-ID: <3530@convex.UUCP>
Date: 30 Nov 89 15:03:32 GMT
References: <1989Nov23.165606.27671@utzoo.uucp> <117.UUL1.3#5131@mvac23.UUCP> <5104@tekig5.PEN.TEK.COM>
Sender: usenet@convex.UUCP
Reply-To: dodson@convex.COM (Dave Dodson)
Organization: Convex Computer Corporation, Richardson, Tx.
Lines: 20

In article <5104@tekig5.PEN.TEK.COM> philj@tekig5.PEN.TEK.COM (Phil Jansen) writes:
>Hi.  I heard a rumor that NASA was working on improving the shuttle main
>engine thrust by 50%  (maximum power right now is 104%).
>My question is, why improve thrust to ~150%?  Since the shuttle was designed
>for only 3G's of acceleration, what good does the extra power do?  Doesn't it
>just mean you use your fuel faster?

If an SSME failure occurs early in the flight, it is impossible to reach
orbit, presumably because the remaining two engines cannot burn the fuel
fast enough to impart the required energy in a timely fashion.  If the
remaining SSMEs could be throttled up, the Return to Launch Site and
trans-Atlantic abort modes might be reduced or eliminated.  Furthermore,
it might be possible to use more thrust while the system is heavy to
improve the payload-to-orbit capability, throttling down appropriately
to prevent overstressing anything.

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Dave Dodson		                             dodson@convex.COM
Convex Computer Corporation      Richardson, Texas      (214) 497-4234