Re: Are there any Space Elevator experts here?

From: Uncle Al (UncleAl0_at_hate.spam.net)
Date: 07/28/04 

Date: Tue, 27 Jul 2004 19:53:18 -0500

George wrote:
>
> Sorry if this has been discussed.
>
> Every time I read an Arther C. Clarke novel with his Space Elevator
> in it, this question comes to mind, but I've never seen it
> specifically analyzed.
>
> I'm talking about the change in orbital velocity which the object
> being raised or lowered must experience. At the earth's surface on
> the equator, an object at the bottom of the elevator has an
> orbital velocity of about 1038 mph (3693mi * 2pi / 24hrs). But by
> the time this object has been raised to geosynchronous orbit
> directly above that point on the equator, it's orbital velocity must
> have been increased to about 6859 mph (26200mi * 2pi /24hrs).
> Something has to impart the needed "sideways" acceleration to
> achieve a delta-V of about 5821mph. Otherwise, the elevator cable
> or shaft will bow backward (Westward) as the payload climbs the
> cable, and bow forward as it climbs back down to earth.
>
> It may be that the bowing just happens, but isn't big enough to
> matter. Of course that would depend on the size of the payload
> going up or down the cable, and possibly on the speed of ascent or
> descent. But I just wondered if anyone can point me to a source
> where this problem has really been addressed. I assume this
> problem isn't a fatal flaw in the concept, but I would like to see
> where someone has run the numbers to prove that.
>
> Arthur, are you out there?

It won't work. The minimum energy curve from surface to
geosynchronous orbit is not a straight line. The added tensile
stress and length dooms a construct that cannot be built because
of its tensile stress and length. It must be constructed of
dielectrics or the Earth's billowing magnetosphere will roman
candle it by induction. If it is non-conductive, what powers the
gondola up and down? A funicular is asinine - the weight. The
stretch can only propagate at the speed of sound. 24,000 miles
is hours of delay. Cable inertia alone is damning.

NASA, "we will launch the Space Scuttle 5000 times to build the
Beanstalk."

Right. Uncle Al bets 2 and out. 

--
Uncle Al
http://www.mazepath.com/uncleal/
 (Toxic URL! Unsafe for children and most mammals)
http://www.mazepath.com/uncleal/qz.pdf

Relevant Pages

  • O/T - Space elevator to become reality
    ... Japan hopes to turn sci-fi into reality with elevator to the stars, ... cracking the greatest sci-fi vision of all: the space elevator. ... The biggest obstacle lies in the cables. ...
    (uk.media.tv.misc)
  • Re: Naive questions about a space elevator
    ... I like the space elevator a whole lot. ... about +/- 300 miles from the equator? ... wind loading. ...
    (sci.space.policy)
  • Re: Burt Rutans plans for a manned mission to Mars
    ... :>Calculate the mass of your space elevator. ... :>costs to put up at current launch costs. ... the hell do you need to bring up from Earth? ...
    (sci.space.policy)
  • Re: Are there any Space Elevator experts here?
    ... > Every time I read an Arther C. Clarke novel with his Space Elevator ... > or shaft will bow backward as the payload climbs the ... and bow forward as it climbs back down to earth. ... Rather than a space elevator, ...
    (sci.physics)
  • Re: Are there any Space Elevator experts here?
    ... >>Every time I read an Arther C. Clarke novel with his Space Elevator ... >>or shaft will bow backward as the payload climbs the ... > of its tensile stress and length. ... Uncle Al bets 2 and out. ...
    (sci.physics)