[net.space] Why are SSMEs on SS?

lynn.es@XEROX.ARPA (04/26/84)

"if the Shuttle Main Engines are used only with the external tank, why
aren't they //mounted\\ on the tank?"

The shuttle main engines are mounted on the Shuttle rather than the
External Tank so they can be brought back for reuse.  The tank is
relatively cheap and expendable.  Tossed at nearly orbital speed, it is
destroyed on reentry, and so would the engines be if they were mounted
on the tank.
/Don Lynn

Spitzer%pco@CISL-SERVICE-MULTICS.ARPA (04/27/84)

From:   Charlie Spitzer <Spitzer%pco@CISL-SERVICE-MULTICS.ARPA>

Because the ET drops off and burns up. The engines are reusable, and
they wouldn't be in very good shape after dropping out of near-LEO.
 Charlie Spitzer
 (Spitzer%pco@CISL)