Moon Base baby steps

"Joseph S. Powell, III" wrote in message ...

If you want it to work for longer than the two weeks that a lunar
day lasts, that is...

(Also, Lunar dust is very sticky--a problem they have to face on Mars
as well, with sand accumulating on the solar panels and in the mechan-
ical parts. On the Moon there's nothing to blow it off with, either.)

Two possibilities: either A. Compressed gas cannisters, like you clean dust
out of your keyboard with, or B. some sort of wiper blades, probably manual,
that and astronaut could just dry-wipe the dust from the pv cells...

C. Elevate the solar panels so that dust isn't kicked up on them by
astronauts tramping or driving nearby. Since there's no wind, what
other source of dust would there be?

In article ,
(Ross A. Finlayson) wrote:

When you say "Space Elevator", what do you mean by that?

This term means a ribbon or cable connecting a satellite in
geosynchronous orbit with a station on the ground.

I think the space tether is completely impractical, maybe not in the
future but currently.

I think your knowledge of the topic is inadequate. Please read some
of the more recent studies before passing judgement on them. Your
statement is literally true, in that the buckytube fibers we need are
still much too short. But at the current pace of progress in that
field, we may well have the needed material in a decade or so. I'm
inclined to think that we'll see an operational space elevator before we
see an Earth-to-orbit magnetic launcher.

My opinion is that an ETOMD is an operational requirement of a
realistic Moon base.

This is clearly incorrect.

- Joe

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In article ,
Alex Terrell wrote:
I've always considered an Earth launch mass driver as impractical, due
to atmospheric heating.

It's difficult, but not quite impossible. It does appear to require
relatively large (and durable!) projectiles, which drives up the size and
cost severely.
--
MOST launched 30 June; science observations running | Henry Spencer
since Oct; first surprises seen; papers pending. |

In sci.space.policy "Greg D. Moore \(Strider\)" wrote:

"Joe Strout" wrote in message
...
In article ,
(Russell Wallace) wrote:

On 24 Jan 2004 06:30:13 -0800, (Alex Terrell)
wrote:

Several things they should do immediately. One of these is to give a
few million $ in research grants to some University Chemistry
department to test methods for processing lunar regolith.

I hate to rain on people's parade, but isn't the _first_ step to put
some mice in orbit, centrifuged to 1/6 G, to check whether it's
intrinsically possible for people to live on the moon in the first
place?

No. People have stayed in microgravity for extended periods of time;
staying on the Moon will be no worse than that (and may be quite a bit
better, for all we know).


"Ah we sure?" Seriously, we may find the 1/6 g isn't enough to prevent
calcium loss, but is enough to make bone breaks more likely than in orbit?


It would be really odd if calcium loss was higher (you can have calcium loss
down here on earth too very easily just not due to gravity) - but really,
the loss is not rapid and anyways, you would not have anybody stay out there
long enough to cause extra probability of breaks.

I mean - seriously, if by teh time we can have somebody stay on moon for a year,
either we will know *HEAPS* more about calcium loss on moon and countering it
or very obviously we haven't even been trying.


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--
Sander

+++ Out of cheese error +++

In article ,
Ross A. Finlayson wrote:
I'm trying to get an understanding of the relationship of exit
velocity, launch track length, G forces, and power. Anybody have a
chart of that?

v^2 = 2*a*d, where v is exit velocity, a is acceleration, d is distance
(length). Something that can reach orbital velocity, assuming fairly
low atmospheric-drag losses, ends up being around 4600 G-km, so getting
the length down to 10km or so requires operation at several hundred Gs.
NB, this assumes constant acceleration.

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.

P = m*a*v, where v and a are as before, m is projectile mass, and P is
peak power. This is up in the gigawatts even for m=100kg; clearly one
needs local power storage that can be charged up slowly and discharged
very quickly. (t = v/a, so that 10km track is covered in about 2s.)
Neglecting losses, energy is 0.5*m*v^2, so for m=100kg we need about
1250kW-hr per shot.

Note that 100kg is almost certainly much too small to get acceptable
atmospheric drag losses, and for that matter the drag loss assumed in the
above example numbers is probably too low even with higher mass.

This is different from a rocket which also makes a sonic boom and
spews tons of poisonous gasses onto the launch pad, at irregular
intervals.

There's nothing particularly poisonous about the exhaust from a
LOX/kerosene or LOX/LH2 rocket.

The Earth to Orbit Mass Driver is a better environmental alternative
to unassisted rocketry.

A point of terminology: this is a catapult, not a mass driver. The two
terms are not synonymous. A mass driver is a particular type of catapult,
which accelerates its payloads in payload carriers, "buckets", which are
decelerated and returned to the head end for re-use.

The launch apparatus is completely reusable,
hundreds, thousands, and perhaps hundreds of thousands of times.

It's also extremely expensive.

Its use introduces no toxins directly into the environment.

Its exit shock wave will be rather hard on the surrounding environment.

...Electricity may be from greener sources...

Or not, as the case may be.
--
MOST launched 30 June; science observations running | Henry Spencer
since Oct; first surprises seen; papers pending. |

On Thu, 29 Jan 2004 12:13:14 +0000 (UTC), Sander Vesik
wrote:

In sci.space.policy Russell Wallace wrote:
I hate to rain on people's parade, but isn't the _first_ step to put
some mice in orbit, centrifuged to 1/6 G, to check whether it's
intrinsically possible for people to live on the moon in the first
place?

Yes. Its just the issue of a lack of place in space to put the mice.

I'd have thought a modest-sized satellite would provide adequate
living space and consumables for some mice for a few months?

Even
more, if you only keep people in space for say a year at a time, you
don't need to do that, we know that people survive a year just fine in
much less than 1/6 G.

Survive in the technical sense of "not dead yet", but I wouldn't call
having your health seriously and to some extent permanently damaged
"just fine". (Particularly since most of their waking hours have to be
spent on keeping it at the "not dead yet" stage.) It's certainly not a
viable basis for long-term human habitation of space, and if that's
not the end goal, why are we spending money putting people in space at
all?

If putting people in space is to be more than a meaningless publicity
stunt, it should be focused on viable long-term objectives, and that
means coming up with ways to enable people to _live_ (as opposed to
marginally survive) in space. And that means adequate gravity is a
requirement, just like adequate food and oxygen. And that means we
need to find out just how much gravity is needed so we'll know what
planets and moons are even potentially viable as living space.

--
"Sore wa himitsu desu."
To reply by email, remove
the small snack from address.
http://www.esatclear.ie/~rwallace

On Fri, 30 Jan 2004 04:26:03 GMT, "Greg D. Moore \(Strider\)"
wrote:

"Ah we sure?" Seriously, we may find the 1/6 g isn't enough to prevent
calcium loss, but is enough to make bone breaks more likely than in orbit?

It's not bone breaks that are the issue, it's that without gravity the
body starts falling apart in many different ways - and much of the
damage is at the cellular level, so there's no way to prevent it other
than to provide adequate gravity.

--
"Sore wa himitsu desu."
To reply by email, remove
the small snack from address.
http://www.esatclear.ie/~rwallace

(Gordon D. Pusch) wrote in message ...
(Alex Terrell) writes:

But no one in this thread has suggested people colonising and breeding
on the moon. I would envisage one year tours of duty, which should be
quite feasible. Pregancy would be punished by an immediate ticket home
(or to an orbiting colony), at unless / until pregnency in 1/6g (or
38g for Mars) is proven safe.

Quite bluntly, if they've paid for their own ticket, it's nobody's bloody
business _what_ they choose to do. It's _their_ right to decide what _they_
consider "safe" --- =NOT= some officious thug appointed by the Nanny State !!!

I was thinking about company workers. The empoyer would immediately
return any pregnent employees for fear of liability in case of damage
to the foetus.

As for private individuals, if any would ever choose to live on the
moon, that's not a straight forward case. It depends how you weigh the
rights of a foetus against the rights of individuals to take stupid
risks.

The main reason why I want to get =OFF= this Mother-May-I rock is that
there are too darned many "safety fascists" like _you_ getting in my face !!! :-(

Firstly I've never been called a safety fascist. Secondly, if you get
to space you're going to find a lot more safety fascists than you do
on Earth. (It's a bit like those safety fascists who don't let you
leave a passenger plane when it's flying over where you want to go to.
The *******s!

On 29 Jan 2004 15:27:59 -0800, (Alex Terrell)
wrote:

Carbon is abundant in many NEOs. Nitrogen is a problem, but not a
major problem until we move from Torus colonies to Cylinder colonies
with their large volumes. Until then, a Heavy Lift Vehicle delivering
NH3 is enough.

As far as air-filler goes, wouldn't argon be an adequate substitute
for nitrogen? I've a feeling the moon and asteroids ought to contain
argon. (Someone correct me if I'm wrong.)

--
"Sore wa himitsu desu."
To reply by email, remove
the small snack from address.
http://www.esatclear.ie/~rwallace

On Fri, 30 Jan 2004 21:16:57 GMT, (Russell
Wallace) wrote:

I'd have thought a modest-sized satellite would provide adequate
living space and consumables for some mice for a few months?

Hopefully such an experiment can be done aboard the ISS, when they
have the right equipment that is. As that would be related to human
sciences and can be better studied on the ISS.

Survive in the technical sense of "not dead yet", but I wouldn't call
having your health seriously and to some extent permanently damaged
"just fine". (Particularly since most of their waking hours have to be
spent on keeping it at the "not dead yet" stage.) It's certainly not a
viable basis for long-term human habitation of space, and if that's
not the end goal, why are we spending money putting people in space at
all?

Taking claim of our rightful property? Why have just one planet, when
there are countless numbers for the taking? Exploration, including
finding these ancient artifacts from the long gone Elders? Becoming
rich on space resources by proving the doubters wrong that it is
possible? :-]

If putting people in space is to be more than a meaningless publicity
stunt, it should be focused on viable long-term objectives,

Since NASA cannot afford long term objectives, then that is why they
are running "one step at a time" in order to build and support what
they can afford in the future.

and that
means coming up with ways to enable people to _live_ (as opposed to
marginally survive) in space.

Yes, just attach heavy weights to their ankles, wrists and torso, when
1/6th G will suddenly seem a lot heavier.

And that means adequate gravity is a requirement,

You can either increase gravity or you can increase mass, where mass
is the easier option when you have some gravity already.

NASA certainly does need artificial gravity in Space though, when we
known that lack of gravity is harmful.

And that means we need to find out just how much gravity is needed so
we'll know what planets and moons are even potentially viable as living
space.

Most are fine I am sure, when your available gravity can be made best
use of by increasing the mass of your people. As just some simple
weights, ideally in a suit, will put much more downwards pressure on
their muscles and bones.

Short term, no problem, but it remains to be seen what living for
years in such an environment is like.

Cardman
http://www.cardman.com
http://www.cardman.co.uk