Space review: The vision thing

"Paul F. Dietz" wrote:

(4) Labor on the moon is orders of magnitude more expensive than on Earth,
and will remain so for the foreseeable future.


Even CATS won't bring down the price, (unless CATS = much lower than
current FedEx rates).

D.
--
The STS-107 Columbia Loss FAQ can be found
at the following URLs:

Text-Only Version:
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"Rand Simberg" wrote in message
...
On Thu, 27 Nov 2003 10:19:40 -0500, in a place far, far away, "Terrell
Miller" made the phosphor on my monitor glow
in such a way as to indicate that:

"Rand Simberg" wrote in message
.. .

There are actually many SPS concepts that are not in GEO, and not that
large per satellite.

...and are only in the MW range, not GW. And therefore have very limited
usefulness as actual powersats.

No, lots of megawatts add up to gigawatts and terawatts.


shrug and then we get into the "how many boosters does it take?" thing all
over again. So far we've just restated the problem in different terms is
all...

--
Terrell Miller


"Very often, a 'free' feedstock will still lead to a very expensive system.
One that is quite likely noncompetitive"
- Don Lancaster

"Paul F. Dietz" wrote:
This is the convenient excuse. The real problem is that utilities
in the US are *too small*, and insist on managing the construction
of their own reactors.

That's a function of the nature of competition between companies, and
the relatively small number of plants built, not the number and size
of the companies. Otherwise, conventional plants would suffer many of
the same problems, which they don't. There is, for conventional
plants, a large cadre of experienced engineers and consultants, a well
codified base of experience, and many firms capable of bidding on the
various parts of the plant. *Absolutely none* of this is true about
nuclear plants, because so few were built and because each is a unique
design.

As a result, they're mostly stuck at the top of the learning curve..

You mean bottom eh?

D.
--
The STS-107 Columbia Loss FAQ can be found
at the following URLs:

Text-Only Version:
http://www.io.com/~o_m/columbia_loss_faq.html

Enhanced HTML Version:
http://www.io.com/~o_m/columbia_loss_faq_x.html

Corrections, comments, and additions should be
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discussion.

Derek Lyons wrote:

Probably not. There's not that much difference between a 100MW
nuclear plant and a 500MW plant. The difficulties lie in places other
than those affected by size.

There's one big difference -- they would have built many more
100 MW plants. They would have been much farther down the experience curve.


I'll note that we're not building many, if any, large coalfired plants
anymore either.

Which has more to do with the NIMBY crowd and changes in the tax laws
as much if not more than anything else.

Actually, it has to do with changes in the laws that required
utilities to buy power from non-utility sources, the precipitous
drop in the price of natural gas in the 1980s, and the advances
in combustion turbines driven in part by aeronautics.

Industries that needed heat installed cogeneration equipment.
A great idea, really, and it provided increases in capacity for
years.

Top. The learning (experience) curve measures unit cost vs. cumulative
production, so it should *decline* with time.

That's the reverse of the usual usage.

You are mistaken.

http://www.bcg.com/this_is_bcg/missi...ence_curve.jsp

http://en2.wikipedia.org/wiki/Experience_curve_effects

http://www.netmba.com/strategy/experience-curve/

(ad google infinitum)

Paul

Mary Shafer wrote:

It seems to me that instead of waiting around for governments to bring
the world CATS, the world should be hoping FedEx will (before 1030 the
next business day, in fact).

I'd bet more on the US military bringing it about, via a demand for boosters
for hypersonic (but suborbital) delivery vehicles.

Paul

Derek Lyons wrote:
"Paul F. Dietz" wrote:

You are mistaken.

No. Your are unable to keep your terms and usages straight. The
term you used (learning curve, which is a slang term, and used in the
sense I stated) and the term you provided cites for (learning curve
effect, a formal term) are two very different things.

Amazing. I introduced the term into this thread, yet *I'm* unable
to keep the terms and usages straight because the way I used the term
doesn't agree with *you*?

Learning curve (and experience curve) are formal terms, used in
an actual engineering discipline (industrial engineering). That you
were ignorant of this, and misunderstood my correct usage of
the term(s), is your fault, not mine.

Paul

william mook wrote:

(1) Uranium ore is concentrated by processes involving liquid water
(and, in some cases, molecular oxygen and organic matter), which is not present
on the moon.


Two points. This is merely a statement about what won't work under
current condtions. Clearly you don't use things that won't work.
Plainly, you change conditions if current conditions aren't favorable.

This was refering to *geological* processes, Mook.

(2) The processing of uranium ores involves water. Again, difficult
to do on the moon.

Same two points. You either change the technology to one that's more
favorable on the moon, or you change the conditions under which you
operate.

This is handwaving.

(3) All industrial processes on the moon suffer from the difficulty of shedding
waste heat. You can design radiators of various kinds, but they will
be more expensive than on Earth.


Depends on the details. Clearly one can imagine all manner of
inefficient means of shedding heat. Plainly this says nothing about
efficient ways of shedding heat. Consider a nuclear plant sitting
inside a thermally transparent dome filled with a low density oxygen
gas. Such a pressure stabilized dome would be rather easy to build.
The nuclear plant could be cooled far more easily than those big ass
towers used here on Earth - since there's no environmental concerns -
especially if remotely tended.

Those big ass towers exploit evaporative cooling. Very effective.
The heat is carried off into the environment by abundant water, and
is radiated to space by the environment at large.

A 1 GW(e) PWR will dissipate at least 2 GW of waste heat.
Radiating that at (say) 400 K (a bit higher than the temperature
at which those cooling towers are operating) will require an area
of about 14 square kilometers. This dire result means that
space reactors will operate at even higher exhaust temperature to reduce
the radiator area, even if this reduces their thermal efficiency
and otherwise increases their operating cost.


HOW TO MAKE REALLY BIG DOMES CHEAPLY:
By taking a shaped asteroidal mass (think of a shaped tank penetrating
round - but modified for our purposes) of Silica - and a shaped mound
of silica deposited at a location on the moon. Drive the asteroid
into the mound under controlled conditions - the heat and dynamics of
the collision are engineered to BLOW A BUBBLE OF GLASS - and fill it
with low density oxygen. Voila' you have any sized bubbles you like -
from baseball sized to the size of cities.

This is one of the most ridiculous loads of crap I've ever had the misfortune
to read. What you'd get is a cloud of silica-bearing ejecta spread over
an area of the lunar surface.


(4) Labor on the moon is orders of magnitude more expensive than on Earth,
and will remain so for the foreseeable future.


How long? How expensive? Clearly, you are merely giving the results
of your intestines - not the results of any clear thinking or
analysis. In other words, pure crap!

Clearly, you are so deep in denial you're on the verge of psychosis.
In *reality*, Mook, it's *really hard* to do *anything* to the moon,
and there's no sign this will change much, handwaving notwithstanding.

Paul

"Paul F. Dietz" wrote:
Derek Lyons wrote:

Conventional plants were scaled up from a larger number of smaller
units, over a longer period of time. But, yes, if coal fired plants
had started at 500+ MW they'd have had the same problems.

Probably not. There's not that much difference between a 100MW
nuclear plant and a 500MW plant. The difficulties lie in places other
than those affected by size.

I'll note that we're not building many, if any, large coalfired plants
anymore either.

Which has more to do with the NIMBY crowd and changes in the tax laws
as much if not more than anything else.

As a result, they're mostly stuck at the top of the learning curve..

You mean bottom eh?

Top. The learning (experience) curve measures unit cost vs. cumulative
production, so it should *decline* with time.

That's the reverse of the usual usage.

D.
--
The STS-107 Columbia Loss FAQ can be found
at the following URLs:

Text-Only Version:
http://www.io.com/~o_m/columbia_loss_faq.html

Enhanced HTML Version:
http://www.io.com/~o_m/columbia_loss_faq_x.html

Corrections, comments, and additions should be
e-mailed to , as well as posted to
sci.space.history and sci.space.shuttle for
discussion.

On Fri, 28 Nov 2003 21:45:58 GMT, (Derek
Lyons) wrote:

"Paul F. Dietz" wrote:

(4) Labor on the moon is orders of magnitude more expensive than on Earth,
and will remain so for the foreseeable future.

Even CATS won't bring down the price, (unless CATS = much lower than
current FedEx rates).

It seems to me that instead of waiting around for governments to bring
the world CATS, the world should be hoping FedEx will (before 1030 the
next business day, in fact).

Mary

--
Mary Shafer Retired aerospace research engineer

"Paul F. Dietz" wrote:
You are mistaken.

No. Your are unable to keep your terms and usages straight. The
term you used (learning curve, which is a slang term, and used in the
sense I stated) and the term you provided cites for (learning curve
effect, a formal term) are two very different things.

D.
--
The STS-107 Columbia Loss FAQ can be found
at the following URLs:

Text-Only Version:
http://www.io.com/~o_m/columbia_loss_faq.html

Enhanced HTML Version:
http://www.io.com/~o_m/columbia_loss_faq_x.html

Corrections, comments, and additions should be
e-mailed to , as well as posted to
sci.space.history and sci.space.shuttle for
discussion.