Here's how to get CATS for 20% of current price.

--- In ssi_list@... "Arthur P. Smith"
> Tango...
>
> I like the idea, but this is where the Earth-based space
elevator has
> a huge advantage: it can easily bootstrap itself to a higher
capacity,
> by pulling up more of itself and growing.

It's still awaiting the perfection of carbon nanotubes while an
orbiting tower is, hold on, smaller in scale, and can be built with
readily available materials like carbon fiber variants. It could go
ahead today!

It's a lot harder to do with
> your design; hence the initial huge launch mass (15,000 tons).
Anything
> that costs $50 billion plus for unproven benefit is basically a
nonstarter.

Considering this proposal was built on half-assed guesses while I
was sitting in front of the computer, perhaps my $30 Billion and
your $50 Billion mean the same thing. Our figures are probably as
accurate as Liftport's $6-10 Billion. Nevertheless, the
technological leap is far less for an orbiting tower/hotel than it
is for a Earthbased tower by orders of magnitude.

Whether it's a non starter at $30 Billion, well that's really
determined by the business model, isn't it? How many tourists are
able to pay $100,000 to $200,000 for a orbital vacation? How much
can be earned by satellite launching, and all the other components
of Liftport's business model, and forever after doing away with
orbital launch requirements and capturing the docking market for sub-
orbital shuttles, etc? I have no idea what the size of the markets
are, so I'm not sure that its a non-starter.

>
> Are you familiar with the tether work by Bob Hoyt and the
people at
> "Tethers Unlimited"? See http://www.tethers.com/ - they seem to
have
> pretty much all these bases already covered.

Very familiar with their work. I've got all of their papers and have
studied them extensively. The rotovator idea I make mention of is
one that they've extensively modeled.

One example I found was a
> 25 ton tether design for moving things form LEO to GTO or Lunar
transfer
> orbit. There's also a "Hypersonic Airplane Space Tether Orbital
Launch
> (HASTOL)" paper that indicates they could have tethers that weigh
just a
> few times a launch payload, even using current materials, so I
don't
> know why your design requires so much mass.
>
> Arthur Smith (apsmith@...

With their HASTOL concept, a sub-orbital shuttle docks with a
rotovator which picks up the payload and tosses it into a higher
orbit and the shuttle then proceeds to land. There is nothing for
tourists here.

I think that tethers are the most elegant solution to CATS, but one
that is really in search of a market. Tourism, as many have pointed
out is a HUGE market, orbit would be a hot destination I'm sure, but
as I've pointed out, it's one thing to take an X-Prize hop for an
hour which will wear thin after a while, its a little better to take
a few orbits around the earth in a capsule and then land, but it's a
whole other realm of experience to stay in orbit at a destination,
and that's what this proposal is all about.

Remember my Bootstrapping in 20 Easy Steps post? It was predicated
on the LEO rotovator and the Lunavator, both of which are detailed
by Tethers Unlimited, and by Hans Morevec, just modified to the
specific purposes of the mission I was writing about. building on
their work and other material that's how I was able to get down into
the nitty-gritty details and develop models for ballast mass build-
up, orbital locations and synchronization of the orbits for the
multi-tether system.

The concept I outlined proceeds from docking by having people or
cargo go onto an elevator and go up to a station/hotel over 1,000 km
overhead.

Now there is a large volume of tourists and industries and services
to underwrite the first foothold in orbit. The volume and resultant
price points are critical. The other proposals didn't address those
issues.

Think for a moment what a 100,000+ tourists per YEAR will do for an
industry? What that industry can underwrite.

TangoMan