SSME's are "rated" at a certain thrust. However, the thrust rating has a
minimum, average and maximum. The "rated" thrust is the average. Therfore,
the engines can be run to an amount greater than "rated" thrust. I am not an
engineer or NASA personel, but I have read that during the nominal acent the
engines are throttled from 64% to 104% but can be throttled to 109% of
rated thrust if necessary.
Jim
"Richard Riley" wrote in message
...
On Sat, 6 Jan 2007 20:36:52 -0600, "Danny Deger"
wrote:

Why does the shuttle throttle to 3 Gs on ascent?

Danny Deger


Heck, I still want to know how to go to 103% throttle.