Trust No One® wrote in message
...

Before anyone flames me I'm not asking WHY the shuttle roll is performed
but
rather HOW the manoeuvre is executed.

Been through the FAQ for the newsgroup, Google searches and a couple of
books and while the WHY is explained, there is precious little on how it
is
actually done.

I did find an reference in the book "Voyage into History" by James
Harwood
to the effect:

"The shuttle's computers moved the booster nozzles in opposite directions
to
roll Challenger about its vertical axis so as the ship climbed toward
space,
the shuttle would be positioned below the external tank with the crew
upside
down relative to Earth and the shuttle's wings level in relation to the
horizon"

Is the author referring to the SRB nozzles?

Would very much appreciate if the one of the many experts on the newsgroup
could take time out to explain the HOW of the manoeuvre or point me to a
reference.

One of those questions I've always wanted to ask in my months of lurking,
but have only now plucked up the courage. Bit of a break from the "Maxson
wars" LOL

Thanks & Best Wishes

Here's a starting point: http://www.moog.com/Space/ .

--
John Thomas Maxson, Retired Engineer (Aerospace)
Author, The Betrayal of Mission 51-L (www.mission51l.com)