Moon Base baby steps

In article ,
Henry Spencer wrote:
Note that you would need a small rocket stage in the projectile,
because an Earth-surface catapult *cannot* put something directly
into orbit -- it can reach only orbits that intersect the atmosphere,
so a bit of rocket fuel is needed to finish the job.

Um, I'm feeling a bit smart-alecky in pointing out that a catapult
*can* put something directly into a long-term stable orbit --
it simply has an eccentricity greater than 1, alias a hyperbolic orbit
...

Also, it can put something into a closed orbit -- it just won't orbit
more than *once* ...

May I suggest "an Earth-surface catapult *cannot* put something
directly into a long-term closed orbit"?

--
Tim McDaniel, ; is my work address

(Ross A. Finlayson) writes:

(Henry Spencer) wrote in message ...
... the gravitational constant G
is 6.7 * 10^11 Newton meters^2/kilograms^2.

small (as in, I'm sure you would notice it, not small effect) typo: 10^-11

-paul-
--
Paul E. Black )

Mike Miller wrote:

(Henry Spencer) wrote in message
...

If you did pressurize the whole tube, almost certainly you would first
coat the walls with a sealant of some kind.

A sealant and pressure vessel.

I wouldn't want to depend on brittle rock holding in 4 or 14.7psi.
While the weight of rock overhead might be enough to contain that,
you're still introducing new, large tensile and hoop stresses to
brittle material.



Build big and flat, say 1 mile square and twenty feet high. Put 60 feet of
regolith/powdered rock roof/shielding on top, and one atmosphere of pressure
will support it.

You could use ropes in tension to keep the roof down, if it was only 40 feet
thick.

It's a different kind of architecture ...

-- Peter Fairbrother

(Russell Wallace) writes:

On 31 Jan 2004 09:20:21 -0600,
(Gordon D. Pusch) wrote:

Why would you have that feeling? Argon is an inert gas, so it doesn't
bond to anything (well, except for fluorine and chlorine, under contrived
laboratory conditions), and its melting point is not that much higher
than nitrogen's. You won't find frozen argon lying around until you're
almost out to Neptune...

But it's produced by the decay of potassium-40, so shouldn't rocks
pretty much everywhere contain some?

"Some," as in trace amounts. Furthmore, the "Big Whack" that created the
clound of debris that formed the Moon heated it to such high temperatures
that it lost nearly its entire supply of volatiles --- including most
of its potassium (radioactive or otherwise).

As for asteroids, they are believed to be basically porous "rubble piles"
that may be expected to outgas any decay-generated argon as fast as it is
produced.


(Is that where Earth's argon supply comes from? Our atmosphere is ~1%
argon IIRC.)

Yes --- _trace_ amounts of argon, just as I said.


-- Gordon D. Pusch

perl -e '$_ = \n"; s/NO\.//; s/SPAM\.//; print;'

Instead of a hemispherical dome, it would probably be a revolved arch,
or onion shaped dome, to help support the burden of the lunar soil.

Ye think in the wrong direction, laddies.

Focus ye sunlight with ye dirty big mirror into the SIDE of a crater
to make ye tunnel. Melted regolith flowing out can form cap of next
tunnel entrance down. Aaargh!

and the whole problem is that the body mistakenly thinks it has an excess.

Why mistakenly? Without load on the bones, there is no need to keep that
extraneous structure in them, so the osteophages will remove it over time.
How should this feedback mechanism know that, at some future time, the load
will increase again?

Jan

Could there be any kind of consensus in this open discussion forum on
how to go about making a moon base?

I think it's a good idea in principle: establishing a permanent human
presence on Luna.

The people there would be busy, in a variety of pursuits. Some would
be assembling structures on the moon. Others survey and prospect. A
poet and chroniclers are there for live updates to Earth. Many are
busy in life support activities. Others are tasked with developing
rudimentary road systems and hardscaping, clearing and marking safe
paths from outpost to outpost. Administration and operations support
help organize the burgeoning group of people and their thousands of
tons of equipment and ephemera from Earth. A significant group does
applied science.

That kind of situation doesn't happen overnight. The first man set
foot upon the moon and it was famous. That was more than thirty years
ago. It's now also been thirty years since the last man set foot on
the moon.

Anyways enough of that, here's what I have in mind for a moon base:

Earth to orbit mass driver: five hundred million
two thousand pods, launched: two hundred million
twenty lunar satellites: sixty million
two hundred electric robotic lunar rovers: fifty million
prefabricated structures, disassembled: two hundred million
three large vehicles, disassembled: two hundred million

All that stuff is launched by the ETOMD, even the nuclear reactors for
electricity generation, it's all hardened for 300 G's and launched to
the moon. With one pod for each satellite, and one pod for each
rover, that leaves about 1800 pods, two metric tons each, or 1500 kg
payload capacity, for around 2500 metric tons of other stuff.

two lunar nuclear reactors: sixty million
three five man landers: eight hundred million
rocket launch: six hundred million

There are initially to be those reactors soft-landed robotically in an
area proximate to the outpost area, with a few kilometers, but behind
some hills, power lines are run from them later back to the central
power outlet. If no nukes then a hundred tons of solar cells and
storage batteries need to go, as well they should. The spare lander
is landed robotically at the lander site. After that then the first
manned lander touches down, and the astronauts, male or female, start
to work and play immediately in setting up sheltered habitats. Then,
the second team of five atronauts get there and helps them. They
start to discover what building stuff on the moon means as they gather
with the help of some of the rovers and perhaps a reassembled
rubber-tired forklift the pods and inspect their contents, test
caverns sited near the landing zones for stability, construct
spacious, shielded, insulated, pressurized domes from the building
materials in the pods, set up the high powered comm beacons, maintain
and inspect each other's health, run lines from the power outlet to
the lights put in place for night work, etcetera.

Cargo continues to arrive about weekly from Earth, and the astronauts
start to work on forming the regolith into structures. A variety of
experimentation takes place to see what again actually working moon
rock on the moon does. Tents are setup in the caverns to determine
their feasibility in actual lunar conditions. Electric powered
processors are started to feed the pilot refineries, fed by choice
rocks picked up by the semi-autonomous teleoperated rovers like
firewood, and drilling and digging operations commence to test mining
equipment in lunar conditions.

Earth operations: two billion dollars

Timeline: with three domes with twenty person capacity each
constructed by 2015, team 1 returns to Earth. Fifty more astronauts
arrive on Luna, team 2 returns to Earth.

How about those apples? Cost: one Earth to orbit mass driver.

Ross F.

In article ,
(Ross A. Finlayson) wrote:

Could there be any kind of consensus in this open discussion forum on
how to go about making a moon base?

It seems unlikely.

Anyways enough of that, here's what I have in mind for a moon base:

Earth to orbit mass driver: five hundred million

And definitely not if you cling to this notion.

We'll see working space elevators before we see an earth-to-orbit mass
driver.

How about those apples? Cost: one Earth to orbit mass driver.

....and a fair sprinkling of pixie dust.

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"Peter Fairbrother" wrote in message
...

Build big and flat, say 1 mile square and twenty feet high. Put 60
feet of regolith/powdered rock roof/shielding on top, and one
atmosphere of pressure will support it.

You could use ropes in tension to keep the roof down, if it was
only 40 feet thick.

It's a different kind of architecture ...


More spherical or cylindrical shapes will give you increased volume for
your surface area, giving you more bang for your buck. You want to make
it as high, (thick), as you can. It is structurally far more efficient
to suspend your floors down from the ceiling, than build them up from
the floor. This is a different mindset, it is far cheaper and easier to
build down, rather than up. I otherwise agree with you though.

Pete.

In article ,
Gordon D. Pusch wrote:
As for asteroids, they are believed to be basically porous "rubble piles"
that may be expected to outgas any decay-generated argon as fast as it is
produced.

No, *some* of them are *possibly* rubble piles. Some are definitely not;
Eros, in particular, appears to be essentially solid rock. Even for the
low-density ones, the matter is not entirely settled -- despite assorted
over-enthusiastic press releases -- because there *are* other theories
for the low density (e.g., substantial ice content).
--
MOST launched 30 June; science observations running | Henry Spencer
since Oct; first surprises seen; papers pending. |