Re: What G-forces do astronauts experience in 'take off'?

Astronauts experience about 3 G's during takeoff.  Although the space 
shuttle could probably go faster, it is limited to this acceleration 
because of the trajectory it takes during launch and because 3 G's is 
considered the maximum G-force the astronauts can withstand and still be 
able to move their heads and arms enough to control the spacecraft (even 
though the shuttle is usually computer controlled during launch, the 
astronauts need to be able to reach the controls if there is an emergency).

If you were in the shuttle during liftoff, the 3 G's would make you feel 
as though you weighed 3 times more than you normally do, kinda like you do 
if you've ever been on a roller coaster that shoots you out of the station 
real fast.

One great site to get more information on this type of stuff is:
www.nasa.gov