Lunar Base Location

NASA's Lunar Architecture Team concluded:
"the most advantageous approach is to develop a solar-powered
lunar base and to locate it near one of the poles of the moon,"

What are the arguments for the poles over the equator?

There is a significant mass penalty for polar landings.
http://www.bbc.co.uk/dna/h2g2/A1110367
The existence of ice at the poles appears to have been discredited.
http://www.universetoday.com/2006/10...southern-pole/
The Moon is ideally suited for nuclear power.
http://www.nss.org/settlement/moon/LUNOX.html

Wouldn't an equatorial location near the lunar limb be preferable?
Like the polar base, a far east or west equatorial base would grant
access to the far-side for radio-astronomy.
http://www.ugcs.caltech.edu/~yukimoon/RALF/

In article . com,
"Neil Fraser" wrote:

What are the arguments for the poles over the equator?

There is a significant mass penalty for polar landings.
http://www.bbc.co.uk/dna/h2g2/A1110367

True.

The existence of ice at the poles appears to have been discredited.
http://www.universetoday.com/2006/10...southern-pole/

Not true, or at least, greatly exaggerated. This study merely shows
that there aren't big slabs of ice anywhere visible from Earth. Big
deal -- nobody was banking on big slabs of ice anyway. A much more
likely (and more useful, for that matter) form of ice has always been
fine grains mixed in with the regolith, and that's just as likely as it
ever was.

The data for elevated concentrations of hydrogen at the poles is pretty
incontrovertible; the only question is exactly where and in what form,
but that doesn't matter very much in the long run; it's there, and it'll
be useful.

The Moon is ideally suited for nuclear power.
http://www.nss.org/settlement/moon/LUNOX.html

True.

Wouldn't an equatorial location near the lunar limb be preferable?
Like the polar base, a far east or west equatorial base would grant
access to the far-side for radio-astronomy.
http://www.ugcs.caltech.edu/~yukimoon/RALF/

True; I'd tend to favor such a location myself, mainly because it's
easier/cheaper to reach, and because it would pretty much force the
decision to use nuclear power, which I'd expect to be substantially
cheaper per MW than polar solar (if they could use the sorts of nukes
the Navy uses).

However, here's another advantage of polar locations: it's easy to duck
out of sight of the sun on short notice. If a big flare erupts without
warning while you're out and about, you can almost certainly find a
crater to duck into or a nice big rock to sit behind, and be pretty well
shielded while you figure out what to do next. That'd be a lot harder
near the equator, where the sun may well be high in the sky. I'll
readily admit this is a small advantage, though.

Best,
- Joe

Joe Strout wrote:

True; I'd tend to favor such a location myself, mainly because it's
easier/cheaper to reach, and because it would pretty much force the
decision to use nuclear power, which I'd expect to be substantially
cheaper per MW than polar solar (if they could use the sorts of nukes
the Navy uses).

The 'sorts of nukes the Navy uses' are hideously expensive - primarily
because of the higher fuel enrichment levels. They also tend to be
somewhat touchy in operation because they are designed to reply
rapidly to changes in demand, as opposed to civilian plants which tend
more towards the stable (I.E. being used as base power). The sole
advantage Naval reactors have over civilian reactors is that they are
designed for long life and to be operated by a small number of people.

Solar would have to be incredibly expensive indeed to compare
negatively to nuclear on cost grounds.

However, here's another advantage of polar locations: it's easy to duck
out of sight of the sun on short notice. If a big flare erupts without
warning while you're out and about, you can almost certainly find a
crater to duck into or a nice big rock to sit behind, and be pretty well
shielded while you figure out what to do next. That'd be a lot harder
near the equator, where the sun may well be high in the sky. I'll
readily admit this is a small advantage, though.

Solar flare radiation is only weakly unidirectional AIUI.

D.
--
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-Resolved: To be more temperate in my postings.
Oct 5th, 2004 JDL

Neil Fraser wrote:

The Moon is ideally suited for nuclear power.

Yes. Unfortunately, public opinion is strongly opposed to nuclear power,
perhaps even more so in space than on the Earth. There will not be a nuclear
fission reactor on the Moon until public opinion changes dramatically.

The use of RTGs in connection with manned exploration on the Moon would
probably also result in a public outcry, but maybe not as strong as if NASA
seriously suggested launching a nuclear fission reactor with a rocket
destined for the surface of the Moon.

/steen

Neil Fraser wrote:
NASA's Lunar Architecture Team concluded:
"the most advantageous approach is to develop a solar-powered
lunar base and to locate it near one of the poles of the moon,"

What are the arguments for the poles over the equator?

There is a significant mass penalty for polar landings.
http://www.bbc.co.uk/dna/h2g2/A1110367

I think the mass penalty is pretty small - a couple extra m/s delta V.

The existence of ice at the poles appears to have been discredited.
http://www.universetoday.com/2006/10...southern-pole/

They found no evidence for large slabs of pure ice.

The Moon is ideally suited for nuclear power.
http://www.nss.org/settlement/moon/LUNOX.html

Perhaps - the polar areas are better suited than the equator as
radiators should avoid site of the sun. Also, at the pole, heat is a
very useful commodity, and nuclear reactors are very good at producing
heat.

Wouldn't an equatorial location near the lunar limb be preferable?
Like the polar base, a far east or west equatorial base would grant
access to the far-side for radio-astronomy.
http://www.ugcs.caltech.edu/~yukimoon/RALF/

The only advantages I can see of an equator base a

1. If the base gets very big, it can be supplied with power by SSP from
L1
2. A launch catapult works better at the equator, especially around
longitude 0.
3. Solar power is easier at the equator. Solar sheets can just be
unfurled on the ground and work below nominal efficiency. At the pole,
they need to be mounted on a rotating mast.

I concluded that an equator base would need to be built for the above
reasons. Whether a polar base is needed is a trade-off on setting it up
versus importing from Earth 12% of then fuel needs.

In article ,
Steen Eiler Jørgensen asdf wrote:
Neil Fraser wrote:

The Moon is ideally suited for nuclear power.

Yes. Unfortunately, public opinion is strongly opposed to nuclear power,
perhaps even more so in space than on the Earth. There will not be a nuclear
fission reactor on the Moon until public opinion changes dramatically.

Perhaps in the US but I don't think this is universally true.

What we need is a list of nations with a higher rate of nuclear
power usage, implying either a relative lack of the energy options the
US enjoys (which I will ignore) or a greater comfort level with the
dreaded Atom, limited to those nations with a native space program
(by which I mean they can build launchers so even if Canada used more
atomic power than the US, which they don't, it wouldn't count).

As near as I can tell, the list of such nations is:

Nation Fraction of
Electrical Power
from Nukes


France 78%
Japan 29%
UK 22%

And France is both much more comfortable with atomic power
than the US or Japan and has a somewhat more impressive track record
in space than Japan.

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James Nicoll wrote:
In article ,
Steen Eiler Jørgensen asdf wrote:

Neil Fraser wrote:


The Moon is ideally suited for nuclear power.

Yes. Unfortunately, public opinion is strongly opposed to nuclear power,
perhaps even more so in space than on the Earth. There will not be a nuclear
fission reactor on the Moon until public opinion changes dramatically.


Perhaps in the US but I don't think this is universally true.


I don't think people are so much afraid of nukes in space per se,*
as launching nuclear material to make it possible. No amount of
reassurance of launcher reliability, or protective encasement of
radioactive material will make them see anything but the utter worst
case, 'finely pulverize the stuff and deliver it directly to the lungs
of everyone within a thousand miles' scenario.

I remember long ago, on the Fidonet Space Development Echo (for
those who know and remember what a BBS was) debating with someone who
proposed getting around that, by mining and processing uranium on the
Moon. It seemed utterly insane to me, to try to re-create the entire
nuclear fuel infrastructure up there, just because we're afraid of the
first 150-odd miles of flight. (assuming there *is* signifigant uranium
ore on the Moon..)


* Save for those who see any use of nuclear power in spase as a vast
space military project in disguise...

--

Frank

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In article . com,
Neil Fraser wrote:
There is a significant mass penalty for polar landings.
http://www.bbc.co.uk/dna/h2g2/A1110367

Less than you might think, although there is some. (Apollo ended up
operating with very thin margins, so small differences could loom quite
large to its mission planners. It was almost always necessary to violate
at least one official flight constraint slightly just to accomplish
lunar-orbit insertion.) It's not a big problem.

The existence of ice at the poles appears to have been discredited.
http://www.universetoday.com/2006/10...southern-pole/

No: http://www.thespacereview.com/article/740/1. In any case, debates
over *ice* don't affect the clear evidence for *hydrogen* deposits of some
kind, which is what really matters.

The Moon is ideally suited for nuclear power.
http://www.nss.org/settlement/moon/LUNOX.html

To quote an old comment by Geoff Landis: "it's easy -- we get the French
to build it and the Russians to launch it". The Moon may be well suited
to nuclear power, but the US at the moment is not well suited to exploit
this opportunity. (Even disregarding political obstacles, just getting a
suitable reactor developed -- there is none right now -- would undoubtedly
cost billions if done by the usual suspects.)

Also, if the Moon were "ideally suited" for nuclear power, it would have
either air or flowing water on the surface to get rid of waste heat.
That's actually a significant headache for lunar-surface nuclear power.

Wouldn't an equatorial location near the lunar limb be preferable?

Yes and no and maybe. Continuous solar power is a big advantage, ditto
access to the polar deposits of hydrogen (and possibly other volatiles).
The equatorial location has better surface conditions and is better placed
for astronomy (half the sky is permanently below the horizon at any single
polar base), but comes up short on power and probably on local resources.
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In article ,
Derek Lyons wrote:
However, here's another advantage of polar locations: it's easy to duck
out of sight of the sun on short notice. If a big flare erupts without
warning while you're out and about...

Solar flare radiation is only weakly unidirectional AIUI.

Correct. The flare particles spiral around the local magnetic field of
the plasma, so they arrive pretty much from all directions. There is some
directionality, but it's weak and complicated and not very useful. You
need full-sphere shielding (although the Moon supplies half of it).
--
spsystems.net is temporarily off the air; | Henry Spencer
mail to henry at zoo.utoronto.ca instead. |

In article .com,
Alex Terrell wrote:
Perhaps - the polar areas are better suited than the equator as
radiators should avoid site of the sun.

Not a major issue -- radiators made of the right materials don't mind a
bit of sunlight. Almost all the energy in sunlight is in visible and near
IR, while almost all the energy emitted from a radiator at any plausible
temperature is far IR. It's not hard to make surfaces that are reflective
to the former and black to the latter -- see the radiators on the insides
of the shuttle cargo-bay doors.
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mail to henry at zoo.utoronto.ca instead. |