You seem to be under the impression that a space station such as the
one Mike refers to below (housing 1000 people) would be at zero gee.
Something that large would be _spinning_, and the inhabitants would
experience a full earth gravity equivalent. They would only
experience zero gee by going to the hub of the station. On the moon
people would only experience 1/6 gee and on mars only 0.38 gee. In
other words, the problems associated with the lack of gravity would
be _worse_ on Mars or the moon than it would on a large spinning
orbital station.

Ed

--- In spacesettlers@yahoogroups.com, "Valens Agnitio"
wrote:
>
> >From: "Combs, Mike"
> >Reply-To: spacesettlers@yahoogroups.com
> >To:
> >Subject: RE: [spacesettlers] Re: Mars and Island One
> >Date: Mon, 12 Apr 2004 08:42:46 -0500
>
> >Why is it taken for granted that a 100 person base on Mars is more
> >inspirational than a 100 person base in HEO? If we could sustain
1000
> >people in HEO for about the same price as 100 people on Mars,
which
> >would be more inspirational?
> >
> >Besides, in the real world, providing returns on investment is
going to
> >have more to do with it than providing inspiration.
> >
> >Regards,
> >
> >Mike Combs
>
> While I agree with you 100% on the economic feasibilty being
paramount to
> the technical, I respectfully disagree with the inspiration angle.
>
> The reason for this is simple: People assign a great deal more
permanance to
> a building, house or home than they do to a motorhome, tent or
trailer. The
> fact is, a space station, wherever its orbit, will be felt as
temporary, and
> the inhabitants as such only doing a tour before coming home. A
permanent
> installation, or even one that just provides the illusion of
permanance, one
> that people live in and resides on martian-firma, or selene-firma,
or what
> have you, will always be a beckoning sign of inhabitance. More
importantly,
> people will see the vast and empty area surrounding such a
building, and
> wonder if they, too, can escape the bounds of earth and rough it
out on a
> distant shore. Furthermore, a base on a planet seems more
accessible, and
> everyone knows that they won't be the best and the brightest'
selected for
> the limited space available on a space station.And besides, people
every
> where can identify with the rough an ready pioneers braving
and 'taming'
> hostile land, much before they can identify with esoteric
experiences that
> bear no relation to anything they have ever been exposed to.
Permanance is
> inspiring...
>
> A further note, aside form the changes in hydrostatic pressures
within the
> body as a result of zero-G, many of the problems can be associated
with the
> body's programming to be efficient: If I don't need strong muscles
and bones
> (as evidenced by the reduced loads), then better to put the
resources
> (energy in the form of food) to better use. These uses would
include
> increased body fat %'s, and/or reduction of caloric intake.
Following this
> line of thought, it seems that 24/7 exposure to 1/3 G would be
vastly better
> than zero-G, and the hydrostatic problem would be greatly reduced
as well.
> It seems to be a very safe guess that the gravity provided by Mars
or Moon,
> coupled with regular resistance training, would go a long, long
way to
> reducing if not eliminating the problems associated with long term
exposure
> to zero-G. In fact, I would readily stake my own health and
fitness on that!
>
> Val
>
available.
us&page=hotmail/es2&ST=1/go/onm00200362ave/direct/01/

From: Valens Agnitio [mailto:volatilis_leo@hotmail.com]

> The reason for this is simple: People assign a great deal more
permanance to
> a building, house or home than they do to a motorhome, tent or
trailer. The
> fact is, a space station, wherever its orbit, will be felt as
temporary,

So we're only discussing human biases, then. Fine. I'm sure you're
correct in pointing out that this bias exists. I would only further add
that it is dead wrong.

Firstly, I'm not interested in comparing a space /station/ with a Mars
/settlement/. It's only fair to compare a space station with a Mars
station with the same crew size, or a space /settlement/ with a Mars
settlement.

So why would a space settlement of the type envisioned by O'Neill be
considered temporary? Because it's in orbit? So is our planet. So is
Mars. Is Mars considered a temporary thing because it orbits the sun,
or is it considered a permanent fixture of our solar system? Why would
a constructed habitat in an independent solar orbit not also be
considered a permanent fixture of our solar system?

> and
> the inhabitants as such only doing a tour before coming home.

Why make this assumption?

> Furthermore, a base on a planet seems more accessible,

It may "seem" that way to you, and perhaps even to others with the same
bias as you, but the facts of the matter are that the surfaces of other
bodies at the bottoms of steep gravity wells are more difficult to
access due to the delta V needed to descend and ascend those gravity
wells.

> and
> everyone knows that they won't be the best and the brightest' selected
for
> the limited space available on a space station.

Why assume space will be limited in space, but not inside a pressurized
Mars habitat? Why assume steep IQ requirements for space, but not for
Mars?

> And besides, people every
> where can identify with the rough an ready pioneers braving and
'taming'
> hostile land, much before they can identify with esoteric experiences
that
> bear no relation to anything they have ever been exposed to.

So in others words this is a prejudice borne of our limited experience
so far. Couldn't agree more.

> Permanance is inspiring...

That's a separate issue, and again, I see no reason to consider a
settlement on a surface to be more permanent than one in orbit.

> These uses would include
> increased body fat %'s, and/or reduction of caloric intake. Following
this
> line of thought, it seems that 24/7 exposure to 1/3 G would be vastly
better
> than zero-G, and the hydrostatic problem would be greatly reduced as
well.

This is speculation in the absence of any supporting scientific data.

Now, it's only logical to expect there would be a reduction in the
harmful effects. But it's equally logical to speculate that a person
living on the moon would experience 5/6th of the problems of a person
living permanently at 0-G (which nobody associated with High Frontier
has ever suggested anyway), or that a Martian would experience 2/3rds of
the harmful effects.

If it does turns out that nothing less the 1-G will prevent serious
health problems, we can spin an orbital habitat on its axis to provide
1-G of centrifugal force. That's not a practical alternative on either
the moon or Mars.

> It seems to be a very safe guess that the gravity provided by Mars or
Moon,
> coupled with regular resistance training, would go a long, long way to

> reducing if not eliminating the problems associated with long term
exposure
> to zero-G. In fact, I would readily stake my own health and fitness on
that!

That's your right, of course, but you're not describing the most
conservative plan. The most conservative plan minimizes the assumptions
about what we can and cannot get along without to the maximum extent
possible.

Regards,

Mike Combs

--- In spacesettlers@yahoogroups.com, "Combs, Mike"

Mike, you've seen this symptom before - it's not right or wrong,
it's simply planetary chauvanism. You've wrestled free of deep
seated biases which make planets look like they are more permanent
or have better potential so I applaud you in your efforts at freeing
others of their biases.

It's kind of like cult deprogramming :)

They will see the light. Especially in orbit. LOL.

TangoMan

--- In spacesettlers@yahoogroups.com, "victoriatangoman"
wrote:
> --- In spacesettlers@yahoogroups.com, "Combs, Mike"

> wrote:
>
> Mike, you've seen this symptom before - it's not right or wrong,
> it's simply planetary chauvanism. You've wrestled free of deep
> seated biases which make planets look like they are more permanent
> or have better potential so I applaud you in your efforts at
freeing
> others of their biases.
>
> It's kind of like cult deprogramming :)
>
> They will see the light. Especially in orbit. LOL.
>
> TangoMan

Hi Tango,

I agree that planetary chauvinism is responsible for people
irrationally discounting the idea of orbital settlements. However,
we cannot discount the idea of "planetary" settlement merely based
upon orbitals' not-so-obvious advantages.

What is appropriate or necessary depends upon the application. The
range of applications may be more limited on the moon vs. orbital,
but that doesn't mean that there are no applications that make the
moon more appropriate than orbital. For instance, if the
application is "mining lunar regolith", then a settlement on the
moon is more appropriate than an orbital settlement.

I personally believe that orbital settlements are the way to go, but
due to the requirements of their construction (ie most raw material
must be off-earth to begin with), such large-scale settlements in
orbit will likely not become reality until we already have a base on
the moon.

Ed

--- In spacesettlers@yahoogroups.com, "Ed Minchau"
wrote:

> I agree that planetary chauvinism is responsible for people
> irrationally discounting the idea of orbital settlements.
> However, we cannot discount the idea of "planetary" settlement
> merely based upon orbitals' not-so-obvious advantages.
>
> What is appropriate or necessary depends upon the application.
> The range of applications may be more limited on the moon vs.
> orbital, but that doesn't mean that there are no applications that
> make the moon more appropriate than orbital. For instance, if the
> application is "mining lunar regolith", then a settlement on the
> moon is more appropriate than an orbital settlement.
>
> I personally believe that orbital settlements are the way to go,
> but due to the requirements of their construction (ie most raw
> material must be off-earth to begin with), such large-scale
> settlements in orbit will likely not become reality until we
> already have a base on the moon.

Ed, I agree with you as well. Basing on the moon is a precursor to
Habitat construction. The initial base may be added onto with
marginal new functions but we'll soon get into a chicken-egg
scenario.

For the base to really expand it will need a purpose. A research
base on the moon won't grow robustly enough to develop into an
economic center for there really isn't much on the moon in way of
economic assets or markets.

There is however an attractive economic region in cislunar space. To
realize the benefits of that region will require further development
of the moon base in order to supply raw materials. The cislunar
economic driver will allow the moonbase to add marginal economic
uses because they serve the cislunar activity and so the moonbase
can grow beyond just a company town.

To realize the potential of lunar development needs a cislunar
driver. On its own the moon offers few economic attractions.

TangoMan

--- In spacesettlers@yahoogroups.com, "Combs, Mike"
> From: sraj [mailto:sraj@m...]

...

> > Putting up a modest operation on Mars with say a hundred people
will
> ignite the mind of the young and eventually make
> > large free floating space habs possible.
>
> Why is it taken for granted that a 100 person base on Mars is more
> inspirational than a 100 person base in HEO? If we could sustain
1000
> people in HEO for about the same price as 100 people on Mars, which
> would be more inspirational?

I have gone over this. Mars is a place which is Earthly, yet not
Earthlike. It may lave running water, even life. It has large cayons,
larger than any on Earth, and the largest vulcanos in the entire Sol
System. Its famliar without losing its mystery. Plus it has the human
mythology as well: the cannals of Lowell, the alien civilizations of
Bradbury, the human upotias of Robinson, and yes, the infamous "Face
of Mars" (which in one mans word "will become the biggest tourist
trap of 22nd century")

Or maybe its just me.

> Besides, in the real world, providing returns on investment is
going to
> have more to do with it than providing inspiration.

True.

--- In spacesettlers@yahoogroups.com, "victoriatangoman"
wrote:
> For the base to really expand it will need a purpose. A research
> base on the moon won't grow robustly enough to develop into an
> economic center for there really isn't much on the moon in way of
> economic assets or markets.
>
> There is however an attractive economic region in cislunar space.
To
> realize the benefits of that region will require further
development
> of the moon base in order to supply raw materials. The cislunar
> economic driver will allow the moonbase to add marginal economic
> uses because they serve the cislunar activity and so the moonbase
> can grow beyond just a company town.
>
> To realize the potential of lunar development needs a cislunar
> driver. On its own the moon offers few economic attractions.

And what is this "economic driver" your talking? Do you have any
suggestions to what it is?

--- In spacesettlers@yahoogroups.com, "victoriatangoman"
wrote:
> For the base to really expand it will need a purpose. A research
> base on the moon won't grow robustly enough to develop into an
> economic center for there really isn't much on the moon in way of
> economic assets or markets.
>
> There is however an attractive economic region in cislunar space.
To
> realize the benefits of that region will require further
development
> of the moon base in order to supply raw materials. The cislunar
> economic driver will allow the moonbase to add marginal economic
> uses because they serve the cislunar activity and so the moonbase
> can grow beyond just a company town.
>
> To realize the potential of lunar development needs a cislunar
> driver. On its own the moon offers few economic attractions.

And what is this "economic driver" your talking? Do you have any
suggestions to what it is?

From: babbler36 [mailto:babbler36@...]

> I have gone over this. Mars is a place which is Earthly, yet not
> Earthlike.

Somewhat true, but we were discussing colonization. Can you name any
places on Earth which were colonized because they were familiar yet
unfamiliar? This aspect might lead to tourism, but not settlement.
Every place on Earth which has been settled was done so because there
was a marketable export, and nearby markets to serve.

> It may lave running water, even life.

The former is inconsistent with all observations made so far, and the
latter is very speculative.

There's been speculation about certain amounts of seepage from canyon
walls in geologically-recent eras, but that's a far cry from what most
people mean by the phrase "running water".

> It has large cayons,
> larger than any on Earth, and the largest vulcanos in the entire Sol
> System. Its famliar without losing its mystery.

But these won't be reasons for building permanent settlements. These
might be reasons for tourism, but this would be limited to people
willing to invest at least 2 or 3 years of their life to the adventure.
Even people who go on African safari or to the Australian Outback don't
devote that much of their life to it at a time.

> Plus it has the human
> mythology as well: the cannals of Lowell, the alien civilizations of
> Bradbury, the human upotias of Robinson, and yes, the infamous "Face
> of Mars"

I can't think of any place in the New World which was settled
exclusively due to the mythology surrounding it. (One might try to
argue that California was settled due to the mythology of "mountains of
gold", but most settlers didn't strike gold, and as it happened there
were other ways of making a living there.)

Regards,

Mike Combs

From: babbler36 [mailto:babbler36@...]

> --- In spacesettlers@yahoogroups.com, "victoriatangoman"
> wrote:
> >
> > To realize the potential of lunar development needs a cislunar
> > driver. On its own the moon offers few economic attractions.
>
> And what is this "economic driver" your talking? Do you have any
> suggestions to what it is?

Read The High Frontier for all the details on this.

In a High Frontier scenario, the natural resources of the moon are
economically competitive. Outside of it, I can't think of a single
resource the moon has to offer which would be economically competitive
at present. "At present" means no commercially-competitive HE3-burning
fusion reactors, and no 30-50 flights per year traffic model for
cislunar space travel.

Regards,

Mike Combs

--- In spacesettlers@yahoogroups.com, "Combs, Mike"
> From: babbler36 [mailto:babbler36@y...]
>
> > I have gone over this. Mars is a place which is Earthly, yet not
> > Earthlike.
>
> Somewhat true, but we were discussing colonization. Can you name
any
> places on Earth which were colonized because they were familiar yet
> unfamiliar? This aspect might lead to tourism, but not settlement.
> Every place on Earth which has been settled was done so because
there
> was a marketable export, and nearby markets to serve.

Well, it is agueable that a Martian colonist would be able to use
terrestial archtechural methods, whereas a space settler would have
master zero-g constution (Althought, it a week aguement: the costs of
masting zero-g building would be less than the benfits of no learning
curve with the limitations of gravity)

> > It may lave running water, even life.
>
> The former is inconsistent with all observations made so far, and
the
> latter is very speculative.
>
> There's been speculation about certain amounts of seepage from
canyon
> walls in geologically-recent eras, but that's a far cry from what
most
> people mean by the phrase "running water".

Yes, that true. It should have been worded "It may have had running
water, maybe even life."

Though, the past or present exsitance of liquid water on Mars, as
well as life, is hotly debated (unlike Mars:)).

BTW, I found a man who claims to have discoved the final proof of
water on Mars. I must say, I am convinced!

http://zinken.typepad.com/palaeo/2004/03/the_final_proof.html

> > It has large cayons,
> > larger than any on Earth, and the largest vulcanos in the entire
Sol
> > System. Its famliar without losing its mystery.
>
> But these won't be reasons for building permanent settlements.
These
> might be reasons for tourism, but this would be limited to people
> willing to invest at least 2 or 3 years of their life to the
adventure.
> Even people who go on African safari or to the Australian Outback
don't
> devote that much of their life to it at a time.
>
> > Plus it has the human
> > mythology as well: the cannals of Lowell, the alien civilizations
of
> > Bradbury, the human upotias of Robinson, and yes, the
infamous "Face
> > of Mars"
>
> I can't think of any place in the New World which was settled
> exclusively due to the mythology surrounding it. (One might try to
> argue that California was settled due to the mythology
of "mountains of
> gold", but most settlers didn't strike gold, and as it happened
there
> were other ways of making a living there.)

Yes, but it does have some real effect: it gives the Mars Society a
constant flow of members and thier dues.

And ulitmatly, I agree with your concutions. The Matian would have
little to offer compartively with Space Settlers. Under the cis-Lunar
devlopment plans, the resdeints of HEO could supply SPS, asteroidal
mining products, mircogravity products, etc. Mars colonist, could
only supply a few minerals for Earth.

--- In spacesettlers@yahoogroups.com, "Combs, Mike"
> From: babbler36 [mailto:babbler36@y...]
>
> > --- In spacesettlers@yahoogroups.com, "victoriatangoman"
> > wrote:
> > >
> > > To realize the potential of lunar development needs a cislunar
> > > driver. On its own the moon offers few economic attractions.
> >
> > And what is this "economic driver" your talking? Do you have any
> > suggestions to what it is?
>
> Read The High Frontier for all the details on this.

Actually, I had the High Frontier for nearly 2 weeks.

It a very good book, and its vision is clear, understandable and
inspiring. The only problem with the book is it very bleak near
future of humanity on Earth. The natural resources of Earth have
proven to been somewhat more pentaful, or we use them more
efficently, that it make the retectal of new source of resource less
ugrent. This is the reason of the delay in space resource
devlopement, besides high launch costs.

> In a High Frontier scenario, the natural resources of the moon are
> economically competitive. Outside of it, I can't think of a single
> resource the moon has to offer which would be economically
competitive
> at present. "At present" means no commercially-competitive HE3-
burning

Valens Agnitio wrote:

>Yes, I remember that one :-) You used 'flabbergasted', but I'm not sure that
>comes close to my own feeling on reading that. One would think that, even
>lacking the education, commonsense would prevail and indicate how ludicrous
>power lines to the moon are, and to a lesser extent, oil on Mars. I thought
>it was common knowledge that oil is formed from vast deposits of organic
>matter over geological time scales. Silly me.
>
>Val
>
Which only proves that once there was life on mars. NASA knows but won't
tell us ... ;-)

Valens Agnitio wrote:

>The reason for this is simple: People assign a great deal more permanance to
>a building, house or home than they do to a motorhome, tent or trailer. The
>fact is, a space station, wherever its orbit, will be felt as temporary, and
>the inhabitants as such only doing a tour before coming home. A permanent
>installation, or even one that just provides the illusion of permanance, one
>that people live in and resides on martian-firma, or selene-firma, or what
>have you, will always be a beckoning sign of inhabitance. More importantly,
>
Some people live on boats (I've been to Amsterdam last month). I'd say
they consider it home just as anyone considers a flat in a regular
building his home. Some American and Australian homes are made in a way
that the house can be towed to another city.

And speaking from personal experience, while buses, trains and planes
have a feeling of being outside in a public place, my car is a place
where I feel at home, no matter where I'm driving. (Which IMHO is the
main reason cars are preferred over public transportation systems , even
if they are much cheaper.)

>It seems to be a very safe guess that the gravity provided by Mars or Moon,
>coupled with regular resistance training, would go a long, long way to
>reducing if not eliminating the problems associated with long term exposure
>to zero-G. In fact, I would readily stake my own health and fitness on that!
>
So would I. In fact I see lower gravity as the main improvement of
quality of live to be obtained in space. As far as I am concerned 1 g
areas may be useful for some industrial processes and some exercise
facilities, but when I come home I would like to turn down gravity to a
comfortable level. As for the exercise part, note that swimming is a
very healthy way of exercising mostly because it does avoid harmful
stress on joints that occur under 1 g.

Axel Walthelm wrote

Valens Agnitio wrote:

>It seems to be a very safe guess that the gravity provided by Mars or
Moon,
>coupled with regular resistance training, would go a long, long way to
>reducing if not eliminating the problems associated with long term
exposure
>to zero-G. In fact, I would readily stake my own health and fitness on
that!
>
So would I. In fact I see lower gravity as the main improvement of
quality of live to be obtained in space. As far as I am concerned 1 g
areas may be useful for some industrial processes and some exercise
facilities, but when I come home I would like to turn down gravity to a
comfortable level. As for the exercise part, note that swimming is a
very healthy way of exercising mostly because it does avoid harmful
stress on joints that occur under 1 g.

Rick Brooks:

Science fiction writer Arthur C. Clarke speculated in Earhlight
(Ballantine, 1955) that lower lunar gravity with less stress on the body
could lead to longer live spans.

It is possible that we could see a separate race of humanity that could not
stand earth gravity, but could easily live to be over a hundred.

Rick

Hi Mike,

I see one very big shortcoming in your arguments. A large enough O'Neil type structure which could make individuals feel really comfortable may be much more expensive than the SPS that you are proposing, as the reason for constructing these O'Neil type structures.

If you wish to make a prototype car, you can try to rig one up in your backyard, but to make a viable O'Neil type structure you would have to invest a mind boggling sum of money. Having made that investment - just as in setting up a production line for manufacturing cars - there would be no sense in stopping with on such structure, the investment would be justified only if you mass produced them!

So the starting point for constructing O'Neil type of structures would be an urgent need perceived by humanity to depopulate Earth!!! (Making O'Neil type structures just for providing an alternate holiday home for people would not be justified with the current state of the world economy). We presently have two people who believe in this necessity. In your website in the story 'If Not For the Fall' you have envisaged about 2 billion people living on Earth eventually. Independently, I have visualised an eventual population of one billion in my earlier post ...........

*(Earth by that time, will be ruled by a Priest Hood, revered all over the Solar System as custodians of the planet where life took shape and humans evolved. They will be revered much more than priests of various religions are today. So it is very unlikely that any one would launch an attack on Earth. Yet to preserve the sanctity of Earth, visitors will have to disembark on Moon and catch a more primitive space ship to Earth. Very high tech gadgets will be banned from Earth by the Priest Hood to protect the truely high tech - i.e. Nature - there will be more advanced form of transport however, which will not depend on roads. Population of Earth at that time will be only about 1 billion. Humans would have realised by then that there are other species which inhabit Earth.)*

Probably there are many others who believe in this idea!? If we can galvanize public opinion towards this task then obviously we can get going. But I am a bit skeptical. Philosophy on Earth has been dead for the last hundred years, replaced by business models, where individuals cannot see beyond the next quarter! : - (

Selvaraj

From: babbler36 [mailto:babbler36@...]

> Well, it is agueable that a Martian colonist would be able to use
> terrestial archtechural methods, whereas a space settler would have
> master zero-g constution

For the construction of the habitat itself, perhaps, but not for
construction of homes, apartment buildings, offices, or shops on the
interior, which would be experiencing 1-G of centrifugal force.

And as for construction of the habitat as opposed to construction inside
the habitat, we don't really have any experience with building
internally-pressurized structures miles across, which is essentially
what's required in either case. Don't get me wrong; I think it's
doable. Just that we'll be in uncharted waters when we do so, creating
the engineering precedents as we go.

> Yes, but it does have some real effect: it gives the Mars Society a
> constant flow of members and thier dues.

True, but can it have any benefit beyond that? I suppose an opposing
viewpoint might argue that High Frontier never accomplished anything
other than bringing a flow of members into the L-5 Society, but I still
have faith that in the future it will accomplish much more than that.

> And ulitmatly, I agree with your concutions. The Matian would have
> little to offer compartively with Space Settlers. Under the cis-Lunar
> devlopment plans, the resdeints of HEO could supply SPS, asteroidal
> mining products, mircogravity products, etc. Mars colonist, could
> only supply a few minerals for Earth.

But what minerals found on Mars would be so valuable as to pay for the
enormous transportation costs of bringing them back to Earth? And even
if such minerals existed, would they be unavailable on any asteroid that
might have lower transportation costs?

Regards,

Mike Combs

From: babbler36 [mailto:babbler36@...]

> Actually, I had the High Frontier for nearly 2 weeks.
>
> It a very good book, and its vision is clear, understandable and
> inspiring. The only problem with the book is it very bleak near
> future of humanity on Earth. The natural resources of Earth have
> proven to been somewhat more pentaful, or we use them more
> efficently, that it make the retectal of new source of resource less
> ugrent. This is the reason of the delay in space resource
> devlopement, besides high launch costs.

It's true that THF reflects the conventional wisdom of the era it was
written in regarding where we are at ecologically speaking. For myself,
I've tried to steer away from arguing the necessity of space settlement
in terms of resource depletion or overcrowding, and have tried to come
at it more from the perspective of heading off the stultification and
regimentation which can overtake a society not pushing at its frontiers.

However, I can see us soon coming to embrace SPS less from the energy
shortage concerns originally offered, and more from concerns about
global warming, perhaps combined with a desire for the West to extricate
itself from political involvement in the Middle East.

Regards,

Mike Combs

From: sraj [mailto:sraj@...]

> I see one very big shortcoming in your arguments. A large enough
O'Neil type structure which could make individuals feel > really
comfortable may be much more expensive than the SPS that you are
proposing, as the reason for constructing these
> O'Neil type structures.

Can we be sure? Check out this to-scale illustration comparing a SPS
with a Bernal Sphere: http://ssi.org/assets/images/Ch09p185.gif (from
http://ssi.org/Don_Davis_Artshow.html)

I don't have hard numbers in front of me right now, but I'm thinking the
mass budget for each is comparable.

O'Neill expressed the opinion that by the time we were far enough into
the SPS program to start getting interested in building space habitats,
the diversion of resources and manpower to make the first one would be
relatively modest compared to the overall enterprise. If we're talking
a SPS enterprise sufficient to make a significant contribution to global
new energy generating capacity, I'd tend to agree. He felt that the
first habitats could be economically justified to prevent continuous
turn-over in the labor force, as they continuously get rotated back to
Earth (and tend not to renew their contracts). In a situation where
there was a reasonably pleasant place to live in HEO, and a worker's
family was there rather than back on Earth, you'd have an easier time
getting them to stick around.

> If you wish to make a prototype car, you can try to rig one up in your
backyard, but to make a viable O'Neil type
> structure you would have to invest a mind boggling sum of money.
Having made that investment - just as in setting up a
> production line for manufacturing cars - there would be no sense in
stopping with on such structure, the investment would > be justified
only if you mass produced them!

100% agreement here. Although I may expect the first habitat will get
built to house space workers, I anticipate that in very short order
subsequent ones will be getting built for immigrants from Earth.

> So the starting point for constructing O'Neil type of structures would
be an urgent need perceived by humanity to
> depopulate Earth!!!

Just one problem. I won't bring up the widely cited bottleneck of space
transportation. Future advances in this area may well surprise us all.
But no settlement movement in our history has ever depopulated the older
region. The settlement of the US didn't significantly depopulate Europe
(only about 1% or less emigrated). That said, population here on Earth
may well decline, but more from rising standards of living than from a
siphoning off of people into space. In the end, that may well be High
Frontier's primary contribution to lowering population growth rates
rather than the people they take away.

> Probably there are many others who believe in this idea!? If we can
galvanize public opinion towards this task then
> obviously we can get going. But I am a bit skeptical. Philosophy on
Earth has been dead for the last hundred years,
> replaced by business models,

Perhaps, but please consider: Have there ever been any colonizations in
Earth's history inspired by philosophy? Or have they all been fueled by
the pursuit of new economic opportunities?

> where individuals cannot see beyond the next quarter! : - (

We might need to come to a more Japanese corporate model, where they
plan out needs and desires decades into the future.

Regards,

Mike Combs