Digest Number 539

> Less that you would think. There have been some proposals
> for launching
> rockets from high-altitude balloons, but the problem with
> getting into orbit
> is chiefly one of achieving the needed velocity. The potential energy
> aspect of it is a relatively minor thing.
>
> That said, ballistic launch from high altitude would help to
> reduce one
> serious problem: air drag (and its attendant heating).
> O'Neill thought that
> the ultimate space launcher might be something like a giant
> mass-driver
> suspended in the upper atmosphere by solar-powered hot air
> balloons. I even
> wrote a SF novella about such a thing named "The Bridge to Space":
>
> http://members.aol.com/howiecombs/bridge.htm

High altitude launches are also portable (if you don't need a tower, you can
literally launch from a boat smack dab on the equator). Only really looks
practical for small, cheap science-class payloads, though; & the technology
still needs a lot of work.

Live in peace
Robert.Clements@...
endeavour2 project http://www.geocities.com/robtclements/endeavour2.html>