>Actually, the USA uses both liquid and solid rockets on the shuttle
>(the little side tanks are the solid boosters).  As I understand it,
>liquid boosters can generate much more raw power than solid ones, but
>must be kept supercooled prior to launch.  Solid boosters also need a
>special hollow design (they burn from the inside out), but they are
>reusable, whereas liquid boosters are not.
>
>Boy, is THIS off topic!

No kidding.

From the on-line Space Shuttle Reference Manual:
"The two SRBs [solid rocket boosters] provide 71.4 percent of the thrust at
lift- off and during first-stage ascent."

and:
"The main engines are reusable, high-performance, liquid-propellant rocket
engines with variable thrust."


http://www.ksc.nasa.gov/shuttle/technology/sts-newsref/stsref-toc.html


later,
newell