JRS: In article , seen in
news:sci.space.science, Gordon D. Pusch g_d_pusch_remove_underscores@xn
et.com posted at Tue, 6 Apr 2004 21:08:29 :


Your proposal is not _totally_ implausible. The energy required to climb
a beanstalk is only a small fraction of the energy required to accelerate
a payload into Low Earth Orbit; the fuel and oxygen tankage required
would be large, but not prohibitively so.



Earth radius is 7 Mm, GSO radius is 42 Mm, so in units of the Earth's
radius 1 and 6.

Potential energy in an inverse square field is inverse linear, so with
it being zero at infinity, it is 1/6 at GSO and 1 on the ground,
difference 5/6.

But the energy required for LEO is half that for escape, so climbing the
stalk to GSO requires 5/3 of the energy to LEO.

"Centrifugal force" will supply a significant part of that energy (by
lengthening the day), but not enough to leave only a small fraction.

Much of the fuel and oxygen will need to be lifted, though there is the
advantage that the exhaust need only carry a little energy other than
that of height.

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