"Mark" wrote in message

(Hallerb) wrote in message
It often made me wonder if launching from the highesr mountain on earth
would
be a improvement

Theoretically, yes, other than the obvious logistical problems of
launching from the top of Everest. AFAIR the atmospheric pressure
drops by about 50% by that altitude, significantly reducing drag.

This is, for example, why Kistler's original K-1 plan called for the
spacecraft to be lifted to 80,000 feet or so on a very simple and
basic rocket or jet-powered platform before the main engines ignited:
in a sea-level launch a lot of fuel is burnt getting to that height
through the dense atmosphere, so just lifing it to that height, even
without providing any horizontal velocity, would have reduced fuel
requirements enough to make an SSTO theoretically feasible without too
many exotic materials.

Mark

That might be an interesting simulation study. The engines would be a bit
more powerful, you'd have a head start in potential energy, etc. Still,
(OTTOMH) I think it wouldn't be that much of a performance gain, since the
sum of the energy needed for orbit is almost all kinetic.

Jon