Space Elevators

I'm pessimistic about space elevators. I can't rule them out, and I
would love it if they turned out to live up to the hopes of their
fans.

But I haven't heard anything that convinces me anyone has worked out
the details of, for example, vibrations in a string that long and
taut under realistic conditions. Then there's the question, where
do you get your angular momentum? If you just lift a payload up the
string, straight up, you haven't given it any angular momentum.
It's still only going fast enough to go around the earth's
circumference once per day, not fast enough to go around
geosynchronous orbit in the same length of time (or the
circumference at whatever height you've gotten it to as you've
lifted it partway). Or to put it another way, how do you offset the
coriolis force as you lift your loads? If you're lifting mass at a
constant rate, you could have the thing hanging at a slight angle to
the west, so that the tension pulls it to the east. But then your
base needs to be capable of resisting that tension, not floating
loose in the ocean as described in the linked article. And how much
extra tension do you need, for how much capacity? Is that going to
put you over the limit of your material strength-per-mass, for some
moderate amount of payload-per-time? If your payloads don't go up
completely uniformly, how does that put vibrations into the system?
How much of an anchor do you need, to attach your base to the ground?

Space elevators may be great for Mars, though.

By contrast, I'm optimistic about electromagnetic systems that
accelerate payloads at a few g though a tunnel and let them go from
a mountaintop.

--- In spacesettlers@yahoogroups.com, "Ryan" wrote:
>
> To the many readers:
> Recently, i have been studying the potential possibilty of a space
> elevator. I came across this article on SPACE.com:
>
www.space.com/businesstechnology/technology/space_elevator_020327-
1.html
>
> Now what i'm looking for is, the views and opions of all of you.
I'm
> looking to compile a report that can be sent to pro-space lobbist
> groups. Later i will disclose my findings from other groups and
also
> describe the pro's and cons that many people believe.
>
> In all reality, if space travel is to become the essence of the
> future, we must continue to focus on the first stage. The first
> stage would be to solve the problem of launching tons of equipment
> into space, which in turn, would be used to launch towards other
> planets. Also we must focus on the funding.But if the heads of the
> goverment, the goverment of many countries, do not fix their
> thoughts we will never escape the earths natural orbit. For
example,
> since the goverments develpment of the space shuttle, we have not
> spent more than 1% of the United States budget on the NASA space
> program. It is now a fact of life, that if space travel is to
become
> a common practice, an affordable program that can be used by upper
> middle class, that it must switch from goverment programs, to
> private organzations. I have thought long and hard about a company
> that one day i will create called SpaceMed. It would be a company
> that focused on the enhanced abilty to create medicines in space.
> The ability to create chemical bonds that are free-floating
without
> any ties to gravity. That alone would bring in millions of dollars
> of research money from countries that wished to send astronuats to
> space but did not have the finanical abilty to do so. Using lunar
> soil and the commisioning of many companies, we could create lunar
> glass. The chemicals of the glass,essential just lunar dust that
has
> been excavated, after being melted, would be turned into glass
> hundreds time stronger than bullet proof glass. This is because of
> the benefits of the lower gravity. In the inner rotating hubs of
> station, crystals could be developed to be used in computer
systems.
> After careful but inexpensive manufactoring processess the
crystals
> could be used to create computers that were faster and more
powerful
> than ever before. All of this extra's would be fueled by the
> excitment of the publc. Not once in history had a private firm
taken
> such a bold chance. I can tell you, without doubt that
millionares,
> senators, and other wealthy men and women would line up for a 5
> million dollar, 4 night stay at the tourism center located in the
> outside rotating hub. This price may seem high, but at one time
men
> payed 20 million. Every part of my program is feasible but the
only
> possible way to open the space market to everyone would be build a
> space elevator. A elevator that could lift 50+ tons and a space
> transportation vechicle. Without a space elevator the rising cost
of
> propellant would continue to raise the cost of space travel. The
> elevator could use a system of hydro-bouys that over the courst of
> one week, develped the power needed to lift a
shuttle/transportation
> vechicle into space in a week. That would put it always on a week
> schudele. The passengers can then depart later on 6 days later and
> use a electromaganet propelled propulsion system that can take the
> passengers to space in under a day.
>
> What i've been getting at is the possiblity of the economic stand-
> point of all of the space settlers goals. To get into space you
must
> first prove to the public the possibilties and the potential of
> space. It's the same for a basketball player or a t.v. show.
Before
> the production company will finance a movie, they poll the public,
> then place advertising and see what the public's reaction is. Then
> they will film and play the pilot program. The same would apply
for
> my program. I don't know if anyone is interested, but i would
gladly
> describe the methods of the transportation vechicle, with or
without