Path: utzoo!attcan!uunet!cs.utexas.edu!usc!zaphod.mps.ohio-state.edu!sdd.hp.com!hplabs!hpcc01!hpbbn!hpbbrd!hpfcmdd!hpfcso!hpfcdc!richard
From: richard@hpfcdc.HP.COM (Richard Artz)
Newsgroups: sci.space.shuttle
Subject: Re: Throttle up to 104%
Message-ID: <4760004@hpfcdc.HP.COM>
Date: 6 Jun 90 06:41:06 GMT
References: <990@gazette.bcm.tmc.edu>
Organization: HP Ft. Collins, Co.
Lines: 18

Timothy  writes:
> On all the shuttle flights @ around 50 + MET into
> the flight, Houston gives the command to go at throttle up
> to 104%. My question is how can you throttle up past 100% ???
> ALso what is MAX-Q
> Someone please explain....

As I heard, the first engines were built for some X thrust-value, later 
improvements allowed 104% to be *nominal*. Of course engineers should have
rescaled this back to 100%, but the instruments were already labeled.

I think the MAX-Q was the max aerodynamical stress point. It can be seen
on the videos. It's the point where their speed is "too fast" relative
to the thickness of the air (which thins out as they get higher).

I know others can explain this better, hope I didn't mess it up to badly.

 Richard Artz / 303-229-2036 / richard@hpfcww.fc.hp.com