Re: GZGL FH - Habitats in Space.

On Wed, 2 Dec 1998, Adrian Johnson wrote:
> >Thomas spake thusly upon matters weighty: 
> >> things like religious freedom account
> >> for a tiny fraction of human exploration (sure, the pilgrim fathers
were
> >> the first to settle in north america, but it wasn't them who truly
> >> colonised the continent).
> 
> Religion has played a HUGE part in the expansion of people around the
> planet

the only particular examples i can think of are the expansion of islam
and
the crusades, and even those were conquest rather than settlement. the
spanish certainly went to south america armed with priests, but they
didn't go in order to convert the natives, they went to enslave them.

> Or, to be really cynical, maybe we could say that
> religion has provided a moral justification for economic
exploitation...

that's pretty much what i reckon, but then i'm a marxist atheist cynic
...

> Incedentally, the pilgrim fathers were by no means the first to settle
> North America - the "native Americans" were...  They arrived looking
for
> happier hunting grounds between 20 and 40,000 years ago, depending on
which
> archaeologist/anthropologist happens to be yelling loudest at the
moment.

fair enough. however, their settling was not in the same vein as
european
settling; they were moving from one home to another, whilst the
europeans
were empire-building. i suppose my model for settlement is based on the 
expansion of mercantile powers rather than migration due to population
pressure; i suppose if the earth's ecology goes down the pan, we could
be
looking at such a situation.

> As for Europeans, the Vikings had settlements in North America back in
the
> 700 - 800 AD period (plenty of archeological evidence for this).

of course. i forgot about the vikings - there have been stones carved
with
runes dug up from lakes in new england, which is pretty cool.

[summary: i think that there will be plenty of industrial activity in
orbit, mostly to do with making and servicing ships, but that people
will 
continue to live on the surface. i still agree that there will be big
habitats in the asteroids.]

> >Counter/Otherpoints: 
> >1. I can make some stuff in space (crystals etc) that I can't manage 
> >in a gravity well.
> Yes!	Like space ships!  Way better to fabricate really big stuff like
> spaceships in zero-g dockyards

doh! yes, in fact it's more or less impossible to build really big ships
on the ground (upwards of 1000 tonnes ish), so orbital shipyards are a
must. however, i think shipyards will be built at planets, at the top of
space elevators. you have to ask if the savings in transport costs
(running a more or less continual employee bus up and down the elevator)
outweight the costs associated with building space habitats - all that
extra life support, structure, room for recreation and support services,
etc. i don't think so - i think employees will live on the ground and
commute up to the facilities.

if you don't have space elevators, things are a little different. if you
have cheap shuttles, then you can have worker populations and lots of
factories on the surface. if surface-orbit transport is expensive, then
you may well want to keep both habitats and facilities (even things like
steelworks which do not gain much from zero-g) in space, to save on the
transport costs of hauling workers and products into orbit. i don't
really
think an interstellar (or even interplanetary) economy can take off
until
there is cheap transport to orbit.

i picture most orbital facilities being a little like this; something in

geosync (the HiBase), where ships dock and people work, the elevator and
something on the surface (the LoBase) which plugs into the planetary
railway net and is where people live. most planets would have one to
four
such assemblies, with all sorts of facilities at each hibase - a few
shipyards, many dockyards, ferry terminals, wharves, quays, shuttle
hangars, warehouses, packaging plants, etc. bigger planets will have a
geosynchronous ring connecting the hibases (does anyone know what these
things are called - mentioned in one or two Clarke books and seen in
Starship Troopers around the moon), with facilities all along it and a
railway running around the ring.

> - so you'd want stuff like the material
> processing there too.

if transport is cheap, you can easily make stuff on the ground and then
lift it up. i think surface factories will be cheaper to run than
orbital
ones.

>  Producing high weight, high bulk items like steel (or whatever)
> for orbital production of starship hulls would be more efficiently
done in
> orbit - lower costs.

why lower costs? what is cheaper in orbit than on the surface? gravity,
air, water, food, heat, construction - all these things are cheaper on
the
surface. everything in space is 15% more expensive due to the overheads.

>  You'd have plenty of orbital facilities dedicated to
> things like this that don't directly have to do with expanding your
> resources...	If you had an asteroid belt with plenty of raw material,
why
> not have a space yard relatively close by - cut down on transportation
> costs for materials.

as i said, putting a steelworks near the asteroid belt is probably
sensible, but if insystem and surface-orbit transport are cheap, then it
might still be cheaper to build your factory on the ground. this is why
we
still ship raw materials around the world rather than processing at
source; the infrastructure on the planet is better

Tom