Two spheres

Message: 11
Date: Sat, 13 Mar 2004 02:12:06 -0000
From: "George Perkins"
Subject: Re: Two Spheres

>--- In spacesettlers@yahoogroups.com, "Joe" wrote:
>>
>>
>> Message: 2
>> Date: Wed, 10 Mar 2004 23:42:37 -0000
>> From: "George Perkins"
>> Subject: Two spheres

>>> We have clearly two fields of influence. One are the fruits,
[Snip]
>> advocacy seems to attract very noticeable ones.

> -------------
> Ah, but space development is most likely to attract serious business
> investors, unlike the Mars and moon enthusiasts. That's where you
> have the best chance of making it.. and where settlers have the best
> chance of thriving instead of just surviving.
> -------------

I, too, am an O'Neillian but - considering that, so far, serious
business investors haven't put a dime into manned spaceflight or any
sort of extraterrestrial habitation - I am unwilling to assert by fiat
that any one vision is "most likely to attract" them.

>>> The former are brain tunneling themselves towards moon and Mars.
[Snip]
>> have pretty clever ideas.

> -------------
> Remember the first attempts at air flight? LOL!
> But this is space. It already has a head start. There's nothing
> super new here. We've walked and we're walking more - we're really
> far ahead of the moon/Mars idiots.
> -------------

. and there you go again - lumping all the moon and mars advocates into
a single group, fruits and non-fruits alike. Gerald O'Neill foresaw the
use of the moon as a source of materials useful for constructing a
permanent space infrastructure; space colonization advocates who adhere
to his original vision (for whatever reason) shouldn't automatically be
dismissed as 'fruits'. Non-O'Neillians who are eager to go to the moon,
may also have sound reasons for wanting to go.

If a space based civilization is your goal, maybe you should leave a few
more options open; one of the big failings of the martian cause is their
obstructionist attitude towards all non-'mars-right-now' options. Truth
is, space advocacy has few enough sane voices being heard - and to have
them attacking each other is NOT advancing the goal of getting
extra-terrestrial settlements built.

>>> To attract the investors we've got to have a good thing.. some
>>> great money-making highly profitable opportunity.

>>> Sitting in space isn't good enough. We have to have something
>>> that will sell.

>> Also given; incidentally, has anyone here been keeping up with the
>> metallic glass research? They seem like a really cool family of
>> materials that are just utterly impossible to manufacture under the
>> influence of gravity. I've heard pundits say that materials from
>> space can never be a paying proposition, with certain very low mass
>> and high value items as potential exceptions (He-3, for example),
>> but the metal glasses give me hope. Whether or not platinum family
>> metals will sell on Terra at reasonable prices may yet depend on
>> demand for platinum being created - by, for example, a hydrogen fuel
>> cell based energy economy.

> -------------
> Good.
> Yes, the liquid metal looks very good to me. I like it.

But I wasn't talking about liquid metals - I was talking about amorphous
(non-crystalline) metals, many of which are (and some are VERY)
transparent. They are also generally stiffer than their crystalline
brethren. Trouble is, making them in containers contaminates your stock
and provides centers of crystallization, which ruins the final product;
likewise gravity creates density driven currents in the cooling metal
which encourages crystallization. As a result, it seems like free fall
is the best place to make this family of neat materials.

Were you talking about iron carbonyl [Fe(CO)5], and similar compounds?
I am really not current on them - other than the mention they get in
Zubrins "Entering Space" (pg 155-156). It does seem a neat concept and,
if the information presented is accurate, possibly useful in space-based
refining; though he never mentions any advantage of using these
compounds in low or zero G. Can they only be formed in free fall? If
not, why isn't this process already being used?

> He-3 would be easier and more profitable extracted from asteroids
> than the moon.

I haven't seen any good numbers of the abundance of He-3 in the
asteroids, though if you could point me to some I'd be grateful. The
moon has been more thoroughly studied than any single asteroid, and any
abundance data we do have represents a known quantity. In any event, I
didn't specify a source for He-3; just that wherever it came from, it
MIGHT be economical to sell it on Terra; whereas other materials almost
seem doomed to be out-competed by existing Terran resources.

> Platinum Group Metals have a bright future. Earth miner can't
> realisticly compete with space miners and the picture only gets more
> exciting when Platinum prices plummet. Imagine Platinum batteries
> at your local store, for example. At the start we make a killing
> and hold tight to the product.

> No problem.
> -------------

I only hope it turns out to be that easy. Imagine being a platinum
miner before the worldwide demand for it skyrockets due to the "Platinum
batteries at your local store" stage. Sure, you can bring 10K metric
tons of it back to Terra, only to find that you've single handedly
flooded the market, and platinum has become cheaper than table salt.
your ROI (return on investment) would be very poor. Or, Imagine being a
manufacturer who develops a great product - made mostly of platinum -
BEFORE the poor sap asteroid miner brings in his 10k metric tons.
Prices for your product will be insanely high, and easily out competed
by conventional versions - and again the ROI stinks. So it degenerates
into something all too familiar to space advocates - the vicious circle:
No profit in material until a market develops, no market develops until
material is common - and no pioneering hero available to get things
going initially, because it means losing your shirt.

>>> Economically, space is much more cost effective than choking on a
>>> big rock. The positive flip side to a positive cheap existence
>>> is dynamite products and services.

>> Agreed - if you are talking about planetary sized bodies. For me
>> the critical consideration is the Delta-V from the surface of the
>> body to its C3=0 orbit. To me, then, Luna makes a certain amount of
>> sense; as do Phobos, Diemos, Vesta, Ceres, & etc.

> -------------
> You need to study up on your Delta-V's, friend.
> http://www.cygo.com/asteroidway.shtml
> -------------

Two points to make here:
Firstly, I am not certain that you have actually understood me. All I
said above is that I agreed that space is much more economical than a
big rock, and established the criteria for judging what is a "Big Rock".
I didn't give any precise numbers because I didn't have them at hand,
and I thought that the idea that getting materials out of shallower
gravity wells rather than steeper ones would be pretty intuitively
obvious. ALL material in space is in a gravity well of some sort -
unless you have discovered some mass negating technique - and so it
seems inevitable that shipping materials from their point of origin to a
habitat will involve burning some Delta-V just to escape the point of
origins gravity (however weak it may be). Luna seems like it could be a
viable source of materials for construction in the Terra-Luna system,
and so I listed it; obviously I wouldn't want to ship materials to the
Terra-Luna system from Mars, or Ceres. When building near Mars (for
example) then I think it makes a lot more sense to examine the costs of
extracting materials from its moons, rather than shipping materials up
from the Mars surface, or sending them from the Terra-Luna system.

Secondly, I am a little surprised that you have told me to study up on
my Delta-V's, when you have yet to reply to my post responding to you in
the "Bush Space Plan Unwise?" thread. In the post I replied to, you had
made the false assertion that a launch from Luna to Mars would require a
higher Delta-V than a launch from Terra-LEO to Mars. I provided a link
(at Caltech, IIRC) that made the relevant calculations very intuitive
and obvious. The Delta-V's you had cited were badly mistaken.

[Snip - in the interest (too late!) of brevity]