From: vince@offshore.ai (Vincent Cate)
Newsgroups: sci.space.shuttle
Subject: Re: Space elevator (was The Single Biggest ...)
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Robert Munck <munck@mindspring.com> wrote in message news:<k8lq4vscu7aekn14boeanrbals45tlhmn2@4ax.com>...
> On 13 Feb 2003 21:35:59 -0800, vince@offshore.ai (Vincent Cate) wrote:
> 
> >This is 16 times per day or 64 times as often as your 1 time
> >every 4 days.
> 
> Well, yeah, but much smaller payloads (225 kg).

In the design I have it is smaller, but there is no need for it to be
smaller.  For the same strength cable and a far shorter piece (like
500 miles instead of 25,000 miles) a spinning tether can lift payloads
far more often (like 64 times or more).
 
> Both are usable techniques, but I'd rather have one 9,100 kg
> payload than 40 individual 225 kg pieces.  I don't see any
> way you could put people into space.

I was just starting out at that size.  Clearly I would want to build a
stronger tether and also have it spin faster.  But we want to build
the bigger tether using the initial small tether.
 
> It's also quite a bit more useful that the SE goes to GEO
> instead of LEO. In fact, the space elevator lets us sling
> vehicles to Venus, Mars, and Jupiter for free, no rockets.

A spinning tether can sling things too.  It can put them in a GTO and
they could use an ion drive to circularize the orbit if they want GEO.

> I'm not at all sanguine about the practicality of that rendezvous of
> rocket and tether at extremely high altitudes and speeds. I've
> walked through the description of the rendezvous (on tethers.com)
> and feel it's really pretty dicey. A small slip-up could pull the
> tether down and destroy the plane.

Evem if the plane/rocket was hostile, the most it could do is break
off the end of the tether.  It could not pull it down.  I don't expect
there would be any real danger of destroying the plane.
 
> >This does not even count the fact that we use materials that really
> >exist while the geo-stationary uses materials that do not exist.
> 
> Quite true. As I said, we need that one breakthrough. Your scheme
> seems to require a fair amount of development and engineering also.

Development and engineering, yes.  New amazing materials, no.

  -- Vince

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 Vincent Cate                           Space Tether Enthusiast 
 vince@offshore.ai                      http://spacetethers.com/
 Anguilla, East Caribbean               http://offshore.ai/vince
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

You have to take life as it happens, but you should try to make it
happen the way you want to take it.    - German Proverb


