>
> Message: 6
> Date: Mon, 30 Jan 2006 10:14:06 -0600
> From: "Combs, Mike"
> Subject: RE: Digest Number 1285
>>
> Excuse me? Mars colonies may not need an L-2 mass catcher, but they
> most certainly will require Martian mining camps, Martian ore
> refineries, and Martian manufacturing facilities. The only issue of
> contention is: Will it be easier or more economical to set all these
> things up in HEO or on the surface of Mars.
>
>> You don't need to drag asteriods or build lunar mass drivers.
>> In the time required to do that Mars will be smelling of babies.
>
> The ability to economically fabricate large areas suitable for
> inhabitation will have to precede, not follow, major increases in
> population size. To do this will require the setting up of industrial
> infrastructure totally from scratch, the engineering of large pressure
> vessels, and the setting up and balancing of closed ecologies. Please
> note that these requirements will be much the same whether we're trying
> to do this in HEO or the Martian surface.

Its true that large settlements will require industrial facilities were ever
they go. But to my mind Mars has clear advantages.

Mars comes ready made water, in the atmosphere, in the ground and properbly
even as liquid form . It has an atmosphere which provides oxygen, nitrogen
and CO2,
dirt for radiation shielding is outside your door . You can build regolith
covered vaults
for habitation and avoid pressure vessels.

Now I'm not saying large space colonies will never be built. Never is a long
time.
I am saying its far more likely the first permaanant colonies off Earth will
be built
on a planetery surface, not orbit.

ta

Ralph

> Message: 7
> Date: Mon, 30 Jan 2006 20:32:11 -0000
> From: "Dan Wylie-Sears"
> Subject: Re: Digest Number 1285
>
>> The misery in places like Africa has little to do with lack of
>> energy or resources.
>> Its because lead by murderous dictators and corrupt incompetent
>> governments. Powersats or no powersats are not going to change that.
>> Imperial rule and acceptance of the civillised mans burden might
>
> Oh great: the third world should outsource their murderous, corrupt,
> incompetent government, and get the same thing from us at half the
> price. It's been tried. Tribute always flows from the subjects to
> the seat of empire: all roads lead to Rome and all colonial railways
> lead from the mines to the ports.

Yep, thats right. The old colonial built roads, ports and mines. The
current
local African governments are now famous for famine, genocide and AIDs.

But don't worry, as I said imperialism is out of fashion these days. So its
not going to return. Now we just wait for failed states to become crime and
terrorist havens then said in "peacekeepers" to sort out the mess if they
can.

ta

Ralph

> Message: 10
> Date: Mon, 30 Jan 2006 20:54:27 -0000
> From: "Dan Wylie-Sears"
> Subject: Re: Digest Number 1286
>
>> Same thing settlers in America and Australia did. Earn a living.
>
> But tobacco and sugar grow just fine on earth. Or are we sending them
> there as a penal colony?
>

Well, thats a possibility. Do you have any objections? Think it was
NASA scientist and SF author Geoffrey Landis who wrote a short story
with that premise recently. Won a Hugo or Nebula too.

> They need some stuff from the Old World for a while while they get
> started. How are they going to earn that, from Mars?

By finding a product or service which they can export back to Earth.

ta

Ralph

From: spacesettlers@yahoogroups.com
[mailto:spacesettlers@yahoogroups.com] On Behalf Of ralph buttigieg

> Mars comes ready made water, in the atmosphere, in the
> ground and properbly even as liquid form .

It's not the same advantage as easy water availability on Earth. I see
only a small advantage to mining Martian permafrost vs. mining hydrated
minerals from an asteroid.

> It has an
> atmosphere which provides oxygen, nitrogen and CO2,

Yes, but what percentage of the total that we need is made up of
nitrogen and CO2? (I leave off O2 because any operation engaged in
refining ores is going to be producing more oxygen than what's needed.)

I once engaged in a debate with someone who insisted that the ability to
pump in carbon from the atmosphere of Mars was what made settlements on
the Martian surface easier than orbital habitats. I went back to the
Stanford Space Settlement study to determine, of all the things we need
for an independent 10,000 person habitat, what percentage of it is the
carbon. I found the below mass breakout.

>From Earth:
Gas and hydrogen: 21,100 tons ("Gas" probably includes nitrogen)
Biomass: 5,900
Furnishings: 25,000
Colonists: 600

Lunar-derived:
Soil: 220,000 tons
Structure: 500,000
Shield: 10,000,000

So the total for lunar-derived is: 10,720,000
and overall habitat mass is: 10,772,600 tons

Even if we exclude the mass for soil, and the mass for the radiation
shield (a Mars habitat might get by with a radiation shield of 1/3 the
mass, but would still require one), we see that biomass (which would
include more than just the carbon) only represents a hair over 1% of the
total mass required.

What we can get from these mass ratios is that if it might be easier to
process large amounts of steel, aluminum, and glass in HEO than on the
surface of Mars, this could totally overwhelm any slight advantage to
being able to simply pump in some CO2 from the outside. And given the
greater availability of sunlight in HEO and the practicality of large,
flimsy concentrating mirrors in that location, there's every reason to
suppose the first assumption is valid.

> dirt
> for radiation shielding is outside your door .

It must be granted that is a good advantage for Mars (or the moon).

> You can
> build regolith covered vaults for habitation and avoid
> pressure vessels.

They would still be pressure vessels. "Pressure vessels" doesn't
necessarily mean steel or glass skins. (But I should interject that the
demands of local agriculture will still necessitate huge glass-skinned
pressurized structures.) The engineering requirements for containing a
given air pressure are the same regardless of the building materials
chosen.

> Now I'm not saying large space colonies will never be built.
> Never is a long time. I am saying its far more likely the
> first permaanant colonies off Earth will be built on a
> planetery surface, not orbit.

I know that's conventional wisdom, but I don't happen to agree with it.
I don't think it takes into account the economic improvements which can
be had by the horizontal EM launching of raw material off an airless
surface.

Regards,

Mike Combs

>>... as a penal colony?
>
> Well, thats a possibility. Do you have any objections?

It's too expensive, compared to just locking them up here: we'll
never get governments to spring for it. Colonizing Australia was
fairly cheap and the colonists could send back some wool. However,
I will grant you that serving as a penal colony is one area where
Mars does have an advantage over HEO: from Mars you can't readily
escape or drop kinetic-bombs on Earth.

> By finding a product or service which they can export back to
Earth.

So now we're back to the original question. What will they be doing
on Mars? What product will

--- In spacesettlers@yahoogroups.com, "ralph buttigieg"
wrote:
>
> > Message: 10
> > Date: Mon, 30 Jan 2006 20:54:27 -0000
> > From: "Dan Wylie-Sears"
> > Subject: Re: Digest Number 1286
> >
> >> Same thing settlers in America and Australia did. Earn a living.
> >
> > But tobacco and sugar grow just fine on earth. Or are we
sending them
> > there as a penal colony?
> >
> Well, thats a possibility. Do you have any objections? Think it was
> NASA scientist and SF author Geoffrey Landis who wrote a short
story
> with that premise recently. Won a Hugo or Nebula too.
>
> > They need some stuff from the Old World for a while while they
get
> > started. How are they going to earn that, from Mars?
>
> By finding a product or service which they can export back to
Earth.