Moon Base baby steps

In article ,
Jan C. =?iso-8859-1?Q?Vorbr=FCggen?= wrote:
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?

I didn't say it wasn't an easy mistake to make. :-)
--
MOST launched 30 June; science observations running | Henry Spencer
since Oct; first surprises seen; papers pending. |

In article ,
Roger Stokes wrote:
...ends up being around 4600 G-km, so getting
the length down to 10km or so requires operation at several hundred Gs...

...I assume that typical cargo items
could withstand (say) 50g constant acceleration if properly packed and
oriented - correct me if I'm wrong.

Almost everything except sizable living organisms can take *much* higher
accelerations, if some attention is given to this during design. Hundreds
of Gs are not much of a problem. Thousands are quite manageable. Even
tens of thousands are not as much of a challenge as you might think;
remember that WW2 proximity fuzes put *vacuum tubes* in artillery shells.
--
MOST launched 30 June; science observations running | Henry Spencer
since Oct; first surprises seen; papers pending. |

On 03 Feb 2004 22:44:46 -0600,
(Gordon D. Pusch) wrote:

"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).

*blink* Potassium is volatile? I thought it normally formed salts with
fairly high melting point.

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

But not enough to use in quantity? Okay.

--
"Sore wa himitsu desu."
To reply by email, remove
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On Sun, 01 Feb 2004 18:08:42 GMT, "Roger Stokes"
wrote:

Does anyone know whether it is the reduced gravity that causes these medical
problems, or the reduced level of everyday shock and vibration that goes
with it?

Yes, it is the lack of gravity.

If the latter, merely supply a shock and vibration table. The astronauts
would strap themselves in and get a 3-axis shake once a day.

It's the former, so that won't help.

--
"Sore wa himitsu desu."
To reply by email, remove
the small snack from address.
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Pete Lynn writes:

"Peter Fairbrother" wrote

... 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 is structurally far more efficient to suspend your floors
down from the ceiling, than build them up from the floor. ...

Do you mean, just on the Moon (where the weight can be used to
counteract air pressure on the roof) or any where, like Earth?

-paul-
--
Paul E. Black )

Joe Strout wrote in message ...
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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How is it done then?

Imagine you are given control of the resources to put people on the
moon. What is your plan?

How about this, then, imagine the funds are split so three competing
groups are to put separate moon bases on the moon, each with similar
resources. Group A buys rocket launches on current launch platforms
and puts from four hundred to eight or twenty thousand kilograms on
the moon at a time, for hundreds of tonnes. Group B designs a new
launch system, and is able to launch three to eight payloads of twenty
tons, to the moon. Group C implements a mass driver and puts two
thousand tons on the moon, and buys a launch with twenty tons. Then,
they've each spent the same amount of money and all funding is cut and
that is it.

A: 300
B: 200
C: 2000

Another round of funding appears, Group A buys ten more launches and
puts a hundred tons on the moon, Group B makes ten more launches and
puts two hundred, Group C put 4000 tons on the moon.

A: 400
B: 400
C: 6000

Consider dividing those numbers by ten.

The mass driver is the cargo side. It's not about getting men to the
moon, it's about making it possible for them to survive there and
build an infrastructure for others to survive there. The moon is not
the wild west or new world: it's a cold, lifeless, airless rock.

What if rocketry costs diminished by two orders of magnitude? It
would approach the cost of the mass driver. When you figure out how
to improve the cost of the rocket launch by a hundred times, to cut
the cost 99%, that'd be really great.

If you want a space tether, building one requires putting some 25000
tons into LEO. There are working models of mass drivers, and the
entire emplacement would be on the ground.

Rocketry is still required for many reasons. People can't ride the
300G Earth to orbit mass driver, they would die, although live fish
can be sent. They ride rockets. Many Earth orbits would not be very
accessible to a fixed emplacement Earth to orbit mass driver, the pod
construction in its payload/control system ratio would be more
expensive than rocket boosting from Earth.

Rocketry was developed hundreds, more than a thousand, years ago by
the Chinese in fireworks. Consider the recent Wright-fuelled anecdote
about the prelate who sat in the chair with a hundred rockets tied to
it. Electromagnetic launch has about a hundred year history, yet it's
often named for Gauss, who knew that beyond our atmosphere was the
vacuum of space.

Look around you. Consider how many tons of Earthly goods are within
your field of view, including the building.

Consider the mass of a comfortable dwelling and return vehicle for you
and others on the moon for an extended visit. The workspace is
outside putting together the moonbase.

Anyways, enough hyperbole, I guess. What technical, economic, or
political barriers exist to construction of an ETOMD? What would be
its schedule, cost, and unknowns? Can unassisted rocketry put men on
the moon to stay, and if so, how? If not, why not?

With warm regards,

Ross F.

--
Ross A. Finlayson
Finlayson Consulting / Apex Internet Software
http://www.tiki-lounge.com/~raf/
"It's always one more."

In sci.space.policy Joe Strout wrote:
In article ,
(Ross A. Finlayson) wrote:

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.

Sprikling? Nah, come on, it will take pixie dust dumping by the truckloads.


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--
Sander

+++ Out of cheese error +++

In sci.space.policy Henry Spencer wrote:
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).

Surely also at least the double asteroids (two asteroids orbiting each other
closely) are also not rubble piles?

--
Sander

+++ Out of cheese error +++

In article ,
(Ross A. Finlayson) wrote:


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.

How is it done then?

Realistically? With rockets, of course.

Imagine you are given control of the resources to put people on the
moon. What is your plan?

Find the lowest-cost launcher which can be man-rated to our aggreed-upon
safety standards, and also the lowest-cost cargo launcher. By
"launcher" I mean "company that provides launch services." Contract for
a good-sized block of launches from each. Also contract for a smaller
number of launches from whoever comes in as #2, both to help support the
industry, and also to avoid having all our eggs in one basket. Use
these launches to loft the spacecraft, probably in several launches each
and assembled on orbit, and then the crew. Crew goes to moon.

Actually, if I had the resources, I'd first build a staging depot in a
low-inclination orbit. This would serve both as a spacedock, providing
fuel, power, structural support, and a variety of tools to craft being
assembled in orbit; and a fueling station (fuel would be purchased --
perhaps in the form of water -- from the lowest bidder, and then used to
fuel up those translunar craft before they go). But now we're drifting
a little bit into fantasy-land, since while this is a very sensible
plan, it's unlikely that NASA will have the resources to do it.

How about this, then, imagine the funds are split so three competing
groups are to put separate moon bases on the moon, each with similar
resources. Group A buys rocket launches on current launch platforms
and puts from four hundred to eight or twenty thousand kilograms on
the moon at a time, for hundreds of tonnes. Group B designs a new
launch system, and is able to launch three to eight payloads of twenty
tons, to the moon. Group C implements a mass driver and puts two
thousand tons on the moon, and buys a launch with twenty tons. Then,
they've each spent the same amount of money and all funding is cut and
that is it.

But you said "similar resources." So I don't think Group C would have
the pixie dust it needs to complete its earth-to-orbit mass driver. The
pesky laws of physics (and economics) will get in the way.

Note, however, that under the plan I sketched out, NASA (or whoever's
going to the moon) would be buying largish quantities of simple
materials (e.g. water) on orbit, from the lowest bidder. So you would
be free to try and convince investors that your ETOMD concept will work
and could undersell other suppliers. I certainly wouldn't be such an
investor, of course, since I don't think it can work. But I wouldn't
stop you from trying.

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In article ,
Sander Vesik wrote:
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...

Surely also at least the double asteroids (two asteroids orbiting each other
closely) are also not rubble piles?

They might be. A close encounter with a planet can split a rubble pile
into a pair of rubble piles, by tidal interaction. (In fact, one of the
points offered in support of the rubble-pile hypothesis is precisely that
we see a suspiciously large number of double asteroids, which ought to be
fairly rare unless there is some specific mechanism that creates them.)
--
MOST launched 30 June; science observations running | Henry Spencer
since Oct; first surprises seen; papers pending. |