RE: Re: [OT] Beanstalk anyone?

Attaching a mass to send up doesn't necessarily have to tug the whole
thing down either.  A couple of solutions are to have the same mass
coming
down as going up (if the top end were in orbit near an asteroid being
mined and ore was shipped down), or to have the counterweight at the top
with an adjustable length tether.  When you attach a elevator at the
bottom, let the counterweight out a bit and reel it in as your elevator
climbs to the center of mass.

Another consideration is how much is an elevator going to affect the
whole
system?  This thing is going to be HUGE, and have a lot of mass.  50
tons
of mass a day may only be a small perturbation force compared to even
things like wind.  The gravity from the moon and sun are also going to
be
pretty hefty perturbations on its stability as well, just think what
they
do to the oceans every day.

For a couple of additional references:
http://www.aleph.se/Trans/Tech/Megascale/tower.txt

http://www.aleph.se/Trans/Tech/Megascale

Randy Wolfmeyer

On Thu, 28 Mar 2002, Bell, Brian K (Contractor) wrote:

> No, you are correct. And this is necessary to maintain tention on the
> beanstalk. If you put the end mass at the orbital velocity point, you
will
> pull the whole thing down every time you send up a mass (as you pull
it into
> a slightly lower, unstable, orbit). Therefore the angular force of the
> endmass has to be greater than the pull of gravity on the end mass,
the
> beanstalk, and any payload (including transport) that you send up the
stalk.
> Or at least that is how I understand it.
>
> -----
> Brian Bell
> -----
>
>
>
> -----Original Message-----
> From: Brian Bilderback [mailto:bbilderback@hotmail.com]
> Sent: Thursday, March 28, 2002 14:31
> To: gzg-l@csua.berkeley.edu
> Subject: Re: Re: [OT] Beanstalk anyone?
>
> [snip]
>   But if it extends further
> out, two things will happen:	the beanstalk is going to be pulling it
along
> at greater velocities in order to keep up with the base point on the
> surface, and the necessary orbital velocity will DECREASE.  That means
a
> stalk end set further out will be tugging at it's stalk, since it will
> probably be at escape velocities.  if untethered, it should go
flinging
> away.
>
> Or am I missing something?
>
> 3B^2