From: vince@offshore.ai (Vincent Cate)
Newsgroups: sci.space.policy
Subject: Re: Space elevator vs Rotovator
References: <1064366747.427110@kyle.snap.net.nz>
NNTP-Posting-Host: 209.88.68.230

"Pete Lynn" <pete@peterlynnkites.com> wrote in message news:<1064366747.427110@kyle.snap.net.nz>...
> Secondly,  it would seem to me that the low cost path to a rotovator,
> (for which the numbers do seem to add up to me), is going to be via a
> small CATS rocket vehicle, initially launching, (among other things),
> then servicing said rotovator.

Something like the reusable first stage of space-x seems like a very good
RLV for a rotovator.  It should be able to get fair amount to 5 km/sec.
After that it seems like $200 mil or so could be enough to bootstrap to an 
amazing tether system.

I think that tethers can give you more than a factor of 10 reduction 
in cost to GEO, and that an RLV flown often could give you more than 
a factor of 10, so the combination could reduce costs by more than 
a factor of 100.  So I think you could build a system that could make
money at $60/lb to GEO.   In particular if this is 2 way tourism 
traffic where the tether gets the energy back when they come down.

> Why does my understanding seem to be so different to others?  If I am
> wrong, why?

I agree with you.  Our site, spacetethers.com, is promoting a rotovator.
I think that the Space Elevator idea gives Space Tethers a bad rep.  
In fact, I have written up something on this at:

    http://spacetethers.com/badrep.html

I think that the Space Elevator is just easier for people to understand
and so it has gotten far more publicity.  Some day the rotovator idea 
will win out, but maybe not till after it is built.

  -- Vince