Questions about "The High Frontier"

Hop David wrote:

As to carracks, there were indeed carracks around in the 15th century...

Ferdinand III of Castille was not alive in the 15th century.
http://en.wikipedia.org/wiki/Ferdinand_III_of_Castile

What the hell does this have to do with crossing the Atlantic then?
If your going into early exploration of the Atlantic, then look into
Henry The Navigator of Portugal.
The Portuguese were way ahead of Spain in exploring the Atlantic,
particularly in what laid along the east coast of Africa.
If you want to go into something earlier than that, check out the
Vikings going to Vinland.
They found America, thought it wasn't worth it, and abandoned their
settlements.
If you want to see exploration done with a purely profit-based
conception as it's driving force, then check out the voyages of the
giant Chinese trading fleet in the early 1400's:
http://www.pbs.org/wgbh/nova/sultan/explorers.html
That was the only time in naval exploration that a country ever put
anywhere near as much effort and treasure as a nation in the late 20th
century did into space exploration...they built a huge fleet of very
expensive ships specifically to set out into the oceans of the world and
set up trade with the places they would find; their biggest ships were
huge - big enough to tow the Santa Maria around like a lifeboat behind
them: http://www.pbs.org/wgbh/nova/sultan/media/expl_01q.html
....and the whole thing was a economic disaster area. The ships never
brought anything back to China that was worth the cost of building them
and sending them out on their voyages, nor found any new sources of
goods that were worth keeping contact with on a ongoing basis by sea.
If Spain hadn't found a lot of gold to steal in the Americas, they
probably wouldn't have shown much interest in the place either.
Even when the English showed up in America to set up agriculture, it was
primarily to establish a source of supply for addictive drugs (tobacco
and sugar cane for rum) manufactured via slave labor, set up by
religious zealots and political outcasts (the Puritans and Cavaliers) in
the period after The Restoration.
If that's the model you want to emulate... religious nutcases who burn
witches, predatory corrupt aristocrats, slavery, and drug lords...for
colonizing space - be my guest.

Pat

Johnny1a wrote:

This isn't really valid, except in the very shortest term. It's
simply impossible to make meaningful predictions about changing
economic, religious, and social impulses over the long term, and any
of those can transform 'utterly impractical' to 'let's do it'.


Well, if you want changing religious impulses, take a look at the
defunct L5 society and Timothy Leary's frozen head popping up like Harry
Seldon to lead the true believers on every few years, while SMI²LEing at
them.
Wonderful guy, ol' Tim Leary, and I don't think we should hold the fact
that his wife and daughter both committed suicide against his inspired
view of a benevolent future for us all.
Question of the week: Is it better to drink poisoned grape Kool-Aid out
of a squeeze tube or in a small sphere with a straw in it in zero g?
Acid is groovy. :-)

Pat

John Schilling wrote:

On Tue, 23 Oct 2007 07:16:47 -0700, Hop David wrote:


John Schilling wrote:


On Fri, 19 Oct 2007 13:10:07 -0500, "Mike Combs"
wrote:


But it's probably going to be a *lot* less expensive if you allow for
the inhabitants to build, provision, and resupply their habitat using
local resources.


And there's every reason in the world to expect an asteroidal settlement to
be doing this.


Except for the critical shortage of local resources that aren't steel or
coal or glass.


And Mars has a much broader range of useful resources


I'm not sure why you would say this. What resources would be available on
the surface of Mars that you couldn't find in a well-selected CC-type
asteroid?


"CC" meaning "Carbonaceous Chondrite" generally?


OK, let's see: How about useful concentrations of Helium, Lithium,
Beryllium, Boron, Nitrogen, Fluorine, Neon, Sodium, Aluminum, Chlorine,
Argon, Potassium, Titanium, Chromium, Manganese, Copper, Zinc, Arsenic,
Bromine, Krypton, Strontium, Zirconium, Niobium, Molybdenum, Silver, Tin,
Antimony, Iodine, Xenon, Barium, Hafnium, Tantalum, Tungsten, Gold,
Mercury, Lead, Bismuth, Thorium, and Uranium.


While CCs may be poor in some those materials, there are other asteroids
that aren't.


What sort of asteroid do you imagine has useful concentrations of, say,
Boron?

Zinc?

Tin?

Lead?



I acknowledge that one asteroid containing all these resources would be
rare.


An asteroid containing *any one* of those resources is going to be rare
indeed. I didn't just pull the list out of my ass, you know.

An asteroid containing useful concentrations of your list of four may be
rare. A metallic asteroid containing usable ores of gold, copper or
cobalt doesn't seem that implausible.

Googling I see aluminum ores such as laterite are formed from weathering
of rock from high rainfall and warm temperatures. I acknowledge this
wouldn't happen on asteroids. Mars evidently had rainfall at one time,
not sure about warm temperatures.

Potassium - Potash seems to be obtained from the ashes of trees. This
seems unlikely on Mars as well as asteroids.

I don't have time or energy to Google the entire list. I'm sure you
didn't pull it out of your ass. I would be grateful if you explained how
you made this list.




On the other hand, there's no superhighways, oceans or rivers that can
be used for transportation on Mars. Transportation will be a substantial
barrier to self sufficiency on Mars as well as among the NEOs.


Transportation by dirt road, is many orders of magnitude cheaper than
space transportation.



Mars definitely has some of those in abundance , and almost certainly has
useful ores of the rest on account of having experienced the same geologic
processes that produced such ores on Earth.


I seem to recall Peter Tillman saying uranium ore was concentrated via
biological processes.


Only a minority of uranium ores, and AIUI it's a minority opinion even
there. Mostly, uranium ores come from abiotic hydrothermal processes,
followed by selective precipitation.



There's certainly some ore concentrating processes on Mars, but I don't
regard it as a given Mars would have all the same ores earth does.


I didn't include any of the minerals for which biologic mechanisms are
necessary. And the purely physiochemical stuff, Mars really does seem
to have had the full range of Earth-style geologic activity. Rather
less active at present, of course, but then there's been nothing going
on to deplete the old ore bodies either.



Carbonaceous chondrites, based on the meteoric evidence, do not.


Meteoric evidence is biased. Some meteorites are much more perishable
than others. If they're not discovered within hours or days of impact,
they're gone. More durable objects are more likely to reach the earth's
surface and become meteorites.


You're talking about iceballs, I assume. Those don't come from NEOs,
except in the "occasionally passes right close to Earth at an ungodly
high relative velocity" definition of NEO. Which is of interest to the
impact-hazards community, but not so much for asteroid mining.

Going to http://neo.jpl.nasa.gov/cgi-bin/neo_elem
I found 1500 NEOs with aphelions below the main belt. Given that NEOs
are short lived, I doubt they've been here since the dawn of the solar
system. I'm inclined to believe they came from the main belt, Trojans or
further out and had their apohelions lowered by planetary influence.

Comet Wilson Harrington has a 4.28 A.U. aphelion. It is a likely
candidate for an object with an insulating mantle protecting an ice
core. Is there a reason an object like Wilson Harrington couldn't have
its aphelion dropped by planetary influence?


NEOs in the sense of being easily accessible for round-trip travel
from Earth, by definition spend most of their time in a climate too
warm for ice to endure.

What do you regard as the aphelion ceiling for easily accessible NEOs?
Given an extinct comet with an insulating mantle & aphelion beneath this
ceiling, do you know how long its ice core would last?




Some carbonaceous chondrites may be homogenous aggregates that haven't
experienced any ore concentrating processes. But this isn't the case for
all asteroids. Metallic asteroids are believed to come from the interior
of large asteroids that were massive enough to have differentiated layers.


Which gives you concentrations of iron, nickel, cobalt, and (for a
perverse but economically relevant definition of "concentration"),
the platinum-group elements.

That's it. A really nice grade of stainless steel, a bit of platinum,
and nothing more. Metallic asteroids will make their owners "rich"
in the way Midas was rich.



I also believe there can be ore concentrating processes going on in
objects that outgas when they're closer to the sun.


Such as?

OK, the outgassing of volatiles is by definition a "concentrating process"
for non-volatiles, but there's nothing to concentrate one non-volatile
over another. And the non-volatiles are almost entirely oxides of
silicon, calcium, and magnesium. So there's your glass, and your
magnesium.

I can imagine outgassing forming tunnels with varying diameters.
Materials of different densities might accumulate in different places as
a tunnel widens or narrows.

There were clays in Tempel 1 that typically require liquid water to
make. That was surprising to some. There were also silicates that must
have formed at very high temperatures. I believe the various processes
comets have gone through are still a mystery. So I am skeptical of any
claims that comets can't have useful concentrations of ore.

I would also not expect all comet nuclei to be the same. So I am
skeptical that all cometary non volatiles would be almost entirely
oxides of silicon, calcium and magnesium.





Asteroids, are where you get steel and coal and glass, and maybe magnesium
and platinum for the export markets, and that's really about it.


I believe water, ammonia and other volatiles not at the bottom of a
steep gravity well and not far from the earth would be valuable.


Yes, but you're not going to find ammonia in a near-earth asteroid.
Not likely you'll be finding much of any nitrogenous compounds there.

I believe a portion of NEOs are extinct comets with an insulating
mantle. If not NH3 then perhaps HCN, HNCO or NH2CHO.


Water, you can get, though only bound up in a mass of carbonaceous
non-volatiles that bears a strong resemblence to coal. And you've
got to be pretty desperate to try and squeeze water from a lump of
coal. But it's at least within the bounds of reason and plausibilty.

Where did the Chinese ice meteorites come from? A prograde comet with a
5.2 A.U. apohelion, no inclination and a 1 a.u. perihelion would hit the
atmosphere at 14 km/sec. This is at the slow end of the cometary
spectrum, the high end being around 72 km/sec. Atmospheric pressure
would exceed crushing strength high in the atmosphere and the high
velocity object would explode in the upper atmosphere. A meteorite is
more likely to reach the earth's surface intact if it hits the
atmosphere at a low velocity.




On http://clowder.net/hop/railroad/asteroidresources.html I give a list
of reasons (with some web cites) why I believe volatile rich NEOs exist.


I only see reasons to believe volatile-rich asteroids exist. Main belt
asteroids, out where the equilibrium temperature is a nice 200K or less.
If you've got anything for volatile-rich NEOs, I couldn't find it.

And even then, that only gives you nitrogen and somewhat more accessible
hydrogen. That still leaves most of the periodic table that you aren't
going to be squeezing out of an asteroid without invoking elfin magic
as a refining technology.

We have some information on the surface composition of some asteroids.
Their interiors are still largely unknown. The various processes that
formed the multitude of asteroids are a mystery, so far as I know. Until
we have a more complete understanding of NEOs, I don't see how you can
say that with confidence.

Hop

Pat Flannery wrote:



in fact, I hate to do this...

I hate to do this... but your sloppy reading is annoying the **** out of
me. Why in the hell would you think Ferdinand III of Castille lived in
the 15th century? Have your reading skills gone down the toilet? Are you
incapable of using Google?


Hop

Hop David wrote:

I believe a portion of NEOs are extinct comets with an insulating
mantle. If not NH3 then perhaps HCN, HNCO or NH2CHO.

Very unlikely, as the amount of energy required to shift their orbital
velocities by such a great degree via their initial path coming in to,
or exiting from, the inner perihelion of their cometary orbits past the
Sun into a orbit via gravitational influence that allows them to become
NEOs would be greater than even a close pass by Venus or Earth would
allow, even passing within 100 miles of either planet's surface.
Besides which, such a deep penetration into either of those planet's
gravity wells would probably cause them to fragment via tidal forces,
like Shoemaker-Levy did when it entered Jupiter's gravity well on its
previous orbit before collision with the planet.



Water, you can get, though only bound up in a mass of carbonaceous
non-volatiles that bears a strong resemblence to coal. And you've
got to be pretty desperate to try and squeeze water from a lump of
coal. But it's at least within the bounds of reason and plausibilty.

Where did the Chinese ice meteorites come from?

Despite the number of years that have passed since that incident, there
has been no independent examination of the samples outside of China to
determine in they were of true extraterrestrial origin.
I can certainly see incoming pieces of space-borne methane ice hitting
Earth's atmosphere from a small comet that was disrupted by tidal forces
as it came through the inner solar system at high velocity and hit
Earth's gravity well, and which didn't have time to volatilize its
interior in the solar heat before running into us, but NEOs come too
close to the Sun to let that be a permanent situation in their orbits.

Pat

Hop David wrote:


in fact, I hate to do this...

I hate to do this... but your sloppy reading is annoying the **** out
of me. Why in the hell would you think Ferdinand III of Castille lived
in the 15th century? Have your reading skills gone down the toilet?
Are you incapable of using Google?

What the hell does Ferdinand III have to do with the evolution of
carracks or the exploration of the Atlantic ocean?
I assumed you meant Ferdinand as in "Ferdinand and Isabella" playing
catch-up with Portugal, and didn't look into the number.
Why didn't you just say "Before Charlemagne there were no carracks, but
just think what would have happened if he had sent the Frankish longship
fleet westward? Zip, instant carracks, and the Portuguese-American empire!"
Like I pointed out, if you want to start exploring the Atlantic,
Portugal is on right coast and right place of the Spanish peninsula to
get started from.
In fact, being surrounded by Spain was probably the greatest incentive
for Portugal to head out to sea via the west imaginable.
What you keep missing is that Columbus' voyage to The New World was
considered a major flop at the time, and he got in a lot of trouble when
he got back to Spain, still considering decades later that he had
reached the eastern shores of Cathay via a oddity in the ocean's
geometry that allowed him to sail over a hump in it (like "the nipple of
a woman's breast" as he described it later in his writings) on his later
voyages, but let him get to the eastern shores of Asia the first time
around, since he apparently sailed nearer her belly button.
In short, the guy was a complete religious loon:
http://www.eagleforum.org/educate/co...columbus.shtml
...and established for the first time the grand concept of religious
wackos leaving the Eurasian landmass and heading for the promised land
over the western horizon.
This has been the curse of the Americas ever since.
It's in the blood.
Hereditary religious insanity.
If they are crooks, transport them to Australia; if they are nuts,
transport them to America.
But get them the hell out of here, pronto. :-)

Pat

On Oct 25, 9:54 am, John Schilling wrote:

Water, you can get, though only bound up in a mass of carbonaceous
non-volatiles that bears a strong resemblence to coal. And you've
got to be pretty desperate to try and squeeze water from a lump of
coal. But it's at least within the bounds of reason and plausibilty.

Actually, some people here on Earth are trying to squeeze water from
coal; mainly to improve the coal's energy yield but also, in arid
regions like Australia, to reuse the water. (I'd guess that the best
use of water wrung/evaporated from coal is to recycle it into slurry
pipelines, an application where you don't have to worry about
detoxifying the water.)

As for the idea that being 1 AU out from the Sun precludes embedded
water ice, we shouldn't be so sure. The very notion of ablative
reentry was substantially inspired by the discovery that meteorites
landed with cold interiors. How cold can they get?

According to rough calculations here

http://www.meteorobs.org/maillist/msg20222.html

perhaps as low as -25 C.

"A meteoroid can be modeled as a sphere. This is generally an
incorrect shape. A plate
is another extreme geometry, also not generally correct."

The more slablike an object, the colder it will be -- and what you'd
like most for ice preservation is something slablike facing the Sun
only edge-on. How slablike are asteroids? On the face of it, not
very. But on the face of *me*, you'll find pores and hairs if you
look close enough. (Please don't.) Cosmic ray milling of regolith
particles leaves them with surfaces rather like mazes of microscopic
slabs. Of course, they are radiating at each other to a great extent,
but also outward.

Not convinced. Well, let's look a Very Big NEO: our Moon. As pointed
out here

http://www.lunarpedia.org/index.php?...ar_Temperature

if you burrow a few meters down at the lunar equator, hellishly hot at
high noon, you get relatively stable temperatures around 23 C. Go up
to 60 degrees latitude and dig to the same depth, it's -24 C. Above
85 deg lat, -110 C. (And the *average* surface temperature of the
Moon is well below 0 C.)

On an asteroid (avg rotation period of 8 hours?), the depth for near-
equilibrium is likely to be much shallower, since there's far less
time for heat soak and reradiation. Asteroids tend to be somewhat
potato-shaped, between a sphere (worst case) and a slab (best case).
A high-albedo, elongated asteroid rotating around an axis more or less
perpendicular to its orbital plane could be expected to be quite cold
inside, even within 1 AU of the Sun.

So ... if there ever was ice inside a stony, high-albedo asteroid, and
that asteroid never got bumped into any orbit very close to the sun,
it's hardly unreasonable to suggest that it still has those
concentrations of ice.

-michael turner

Pat Flannery wrote:



Hop David wrote:


I believe a portion of NEOs are extinct comets with an insulating
mantle. If not NH3 then perhaps HCN, HNCO or NH2CHO.


Very unlikely, as the amount of energy required to shift their orbital
velocities by such a great degree via their initial path coming in to,
or exiting from, the inner perihelion of their cometary orbits past the
Sun into a orbit via gravitational influence that allows them to become
NEOs would be greater than even a close pass by Venus or Earth would
allow, even passing within 100 miles of either planet's surface.

There are a disproportionate number of near earth comets with 5.2 A.U.
aphelions. Comet Wilson Harrington/1979 VA has a 4.3 A.U. aphelion.

There are comets in the main asteroid belt.

So it's not a given a comet has a 30 A.U. or more aphelion.


Besides which, such a deep penetration into either of those planet's
gravity wells would probably cause them to fragment via tidal forces,
like Shoemaker-Levy did when it entered Jupiter's gravity well on its
previous orbit before collision with the planet.

Tempel 1's orbit was changed substantially in 1881. It's not a string of
pearls.

http://www.jpl.nasa.gov/releases/91/...991_1404B.html
"Some asteroids may also be the cores of extinct comets. Scientists
believe that between 10 to 50 percent of the near-Earth asteroids may be
comet cores."

Hop

Pat Flannery wrote:



Hop David wrote:



in fact, I hate to do this...


I hate to do this... but your sloppy reading is annoying the **** out
of me. Why in the hell would you think Ferdinand III of Castille lived
in the 15th century? Have your reading skills gone down the toilet?
Are you incapable of using Google?


What the hell does Ferdinand III have to do with the evolution of
carracks or the exploration of the Atlantic ocean?
I assumed you meant Ferdinand as in "Ferdinand and Isabella" playing
catch-up with Portugal, and didn't look into the number.

If you will, look upthread. Please note my first mention of Ferdinand is
"Ferdinand III of Castille". At that point I thought that would suffice
to name a leader living in a pre-carrack time. Also context should give
a clue I was talking about a pre-carrack time.

In subsequent posts I dropped "of Castille" for brevity's sake. You
seized the opportunity to manufacture a straw man.


Why didn't you just say "Before Charlemagne there were no carracks, but
just think what would have happened if he had sent the Frankish longship
fleet westward? Zip, instant carracks, and the Portuguese-American empire!"
Like I pointed out, if you want to start exploring the Atlantic,
Portugal is on right coast and right place of the Spanish peninsula to
get started from.

I'll try to speak slowly to explain this metaphor.

Ferdinand III's Castille - pre ocean faring nation
Today's U.S. - pre space faring nation

mid Atlantic - worthless place not worth building ships for
LEO - worthless place not worth building ships for

The Americas - vast opportunities worth building ships for.
The Moon, Mars, Mars Moons & Neos - vast opportunities worth building
ships for.

Your post from upthread:

[discussion of developing moon and near earth space]
What this all reminds me of is the Shuttle/ISS argument:
"What can the Shuttle do, now that its military and commercial missions
have been canceled?"
"It can build a Space Station!"
"What purpose will the Space Station serve?"
"It will give the Shuttle something to build!"

The futility of dicking around in LEO has nothing to do with the
potential of the moon and other space resources.

In fact, being surrounded by Spain was probably the greatest incentive
for Portugal to head out to sea via the west imaginable.
What you keep missing is that Columbus' voyage to The New World was
considered a major flop at the time, and he got in a lot of trouble when
he got back to Spain, still considering decades later that he had
reached the eastern shores of Cathay via a oddity in the ocean's
geometry that allowed him to sail over a hump in it (like "the nipple of
a woman's breast" as he described it later in his writings) on his later
voyages, but let him get to the eastern shores of Asia the first time
around, since he apparently sailed nearer her belly button.
In short, the guy was a complete religious loon:

Sometimes I'm entertained by your rambling stories forking into many
tangents. But at the moment I'm annoyed with your inability to focus and
read for comprehension.

Hop

"Johnny1a" wrote in message
ups.com...

The only way any of that would make sense is if the cost of returning
workers to Earth, and the related turnover, was less than the cost of
constructing a habitat. Slot in selected assumptions about relative
cost and you can reach an answer. The answer is almost surely going
to be 'no'.

I'll assume you meant to say "greater than", since you seem to be
disagreeing.

Depends on which ramps down more rapidly: the cost of additional space
construction, or space transportation costs.

I think it would be more correct to say that this won't happen until the
cost of the construction /approaches/ the transportation and training costs.
Reason being that a relatively independent settlement with a closed ecology
in space would surely have more than one use. 90% of the population might
well be the aforementioned space construction workers, but there will be
other customers up there for their own reasons.

--


Regards,
Mike Combs
----------------------------------------------------------------------
By all that you hold dear on this good Earth
I bid you stand, Men of the West!
Aragorn