Everyone knows the rocket equation, and most of us are familiar with
some of the facts of orbital mechanics at a not-really-rocket-
science level. And it's easy to make the connections between
radius, velocity, and acceleration for rotational pseudogravity.

If you're using passive mass as shielding, building bigger gets you
more cubic meters per kilogram of shielding. So you want to build
as big as you have any use for, up to the limits of the strength of
your materials.

But what about radiation shielding? Does twice the mass of magnets
and associated structural materials protect twice the volume of
space? Twice the radius? The square of the relative volume
(relative to some parameter of the structure, so that it will be
dimensionless so you can square it -- and if so, what would the
parameter be)?

Does anyone know?

No answers to those questions, but here's a nice link about magnetic
shielding.
http://www.islandone.org/Settlements/MagShield.html

It mentions that plasma shielding and passive mass shielding work
well together: plasma shielding reduces the energy of incoming
particles, so that it takes less matter to stop them.

I was wondering whether it would be worthwhile to combine radiation
shielding with hydrogen collection. For that matter, how does
hydrogen collection from the solar wind work?

I'm imagining that you would route the incoming positively charged
particles into something like a tank of water, with walls thin
enough that they can get in and enough matter inside that they can't
get through. I'm thinking water in particular because it would mean
just having the aquaculture tanks downstairs next to the hull. And
if you're going to be accumulating hydrogen, the aquaculture tanks
seem like a good place to have it arrive.

Another possible use of magnetically redirected cosmic radiation
might be transmutation of elements. If any of the too-common
elements will turn into something more useful when a proton or an
alpha hits them, then you might as well have them as the passive-
mass component of your radiation shielding, so that when you remodel
the scrap will be more valuable than the original materials. I have
no idea whether that will ever be worthwhile, though.

dsw_s@... writes:

> But what about radiation shielding? Does twice the mass of magnets and
> associated structural materials protect twice the volume of space? Twice the
> radius? The square of the relative volume (relative to some parameter of the
> structure, so that it will be dimensionless so you can square it -- and if so,
> what would the parameter be)?
>
> Does anyone know?

While I do not really know I plan on using Damron plastic and water as
passive protection and spin for gravity. From what I have studied 2 inches of Damron
and 6 inches of water is sufficient for proper protection against 95% of the
radiation even in the worst solar storm.
Water is a good radiation barrier. It is also necessary for all kinds of
things. Since you will have to have the weight you should have it serve two
different purposes.

However, even though this would work within the solar system after reading
the recent report on the Voyager and the termination barrier I am wondering if
it would work while in the termination barrier and beyond. I will have to study
the data more thoroughly than has been published so far.

John Wayne Smith, CEO,
1000 Planets, Inc.
Building a Road to the Stars.
Dream - Think - Build - Go

What's Damron? Google turns up nothing on it but people with that
as their last name. How can it be so effective? I didn't think
chemical structure could be so important to high-energy radiation as
to make two inches of plastic as effective as several feet of rock.
Or does this plastic contain a lot of some heavy element?

--- In spacesettlers@yahoogroups.com, jwsmith42000@a... wrote:
>
> dsw_s@y... writes:
>
> > But what about radiation shielding? Does twice the mass of
magnets and
> > associated structural materials protect twice the volume of
space? Twice the
> > radius? The square of the relative volume (relative to some
parameter of the
> > structure, so that it will be dimensionless so you can square
it -- and if so,
> > what would the parameter be)?
> >
> > Does anyone know?
>
> While I do not really know I plan on using Damron plastic and
water as
> passive protection and spin for gravity. From what I have studied
2 inches of Damron
> and 6 inches of water is sufficient for proper protection against
95% of the
> radiation even in the worst solar storm.
> Water is a good radiation barrier. It is also necessary for all
kinds of
> things. Since you will have to have the weight you should have it
serve two
> different purposes.
>
> However, even though this would work within the solar system after
reading
> the recent report on the Voyager and the termination barrier I am
wondering if
> it would work while in the termination barrier and beyond. I will
have to study

Most anything can be used for radiation shielding.

If you plan on using popcorn - plan on using a lot of it.

Where volume really counts is the space suits. So, please forget popcorn for
those.

Personally, I like toying with the idea of using Gold.

And what better choice, as far as aesthetics goes, for our crafts?

And it gets more practical for small crafts expected to park safely inside a
larger platform or craft.

Ah Gold. Beautiful Gold.

On 10/8/05, jwsmith42000@... wrote:

dsw_s@... writes:

> What's Damron?

Sorry, that is Demron. Even at the end of a very long day I should not be so
sloppy. Try www.radshield.com

> How can it be so effective? I didn't think chemical structure could be so
> important to high-energy radiation as to make two inches of plastic as
> effective as several feet of rock. Or does this plastic contain a lot of some
> heavy element?

I can send you 3 pdf's that will answer that but you can easily find them now
that I have given you the right name.

John Wayne

> I can send you 3 pdf's that will answer that but you can easily
find them now
> that I have given you the right name.

I found some odds'n'ends, but nothing that really convinces me.
The .pdf's would be much appreciated.

--- In spacesettlers@yahoogroups.com, jwsmith42000@a... wrote:
>
> dsw_s@y... writes:
>
> > What's Damron?
>
> Sorry, that is Demron. Even at the end of a very long day I should
not be so
> sloppy. Try www.radshield.com
>
> > How can it be so effective? I didn't think chemical structure
could be so
> > important to high-energy radiation as to make two inches of
plastic as
> > effective as several feet of rock. Or does this plastic contain
a lot of some
> > heavy element?
>
> I can send you 3 pdf's that will answer that but you can easily
find them now

Sent

dsw_s@... writes:

> From what I have studied 2 inches of Damron
and 6 inches of water is sufficient for proper protection against 95% of the
radiation even in the worst solar storm.

Doesn't any plastic degrade quite fast if hit wih radiation?

Rgds

Alan

a.patrick@... writes:

> Doesn't any plastic degrade quite fast if hit with radiation?
>
> Rgds, Alan

No, it does not. Unless specifically designed to do so plastic will last
forever and suffer through all kinds of abuse. This was the major complaint of the
environmental movement against plastic.
Now plastics can be made practically indestructible (only by special order)
or photodegradable (standard).
Photodegradable plastic does decompose when hit by radiation, specifically
sun light.

John Wayne

Yes, Demron's good.

But can this be made from moon materials?

You'd want a shielding you can make for your space suits yourself rather
than depend on costly launches from earth, I'm sure.

On 10/9/05, jwsmith42000@... wrote:

In a message dated 10/10/2005 3:29:16 AM Eastern Standard Time,
space.action@... writes:

>
> Yes, Demron's good.
>
> But can this be made from moon materials?
>
> You'd want a shielding you can make for your space suits yourself rather
> than depend on costly launches from earth, I'm sure.
>

Good question, worth the 300 mile trip to find out. I will schedule it as
soon as is possible and report back.

John Wayne

John.

John.

The moon doesn't have it.

And mooncrete inside a spacesuit just isn't going to work.

Forget Aluminum.

On 10/10/05, jwsmith42000@... wrote:

I'd like to know what you do with these suits after you use them -- because
they get annoyingly HOT after six hours.

Do you wait and use them again?

Or do you toss them?

I really don't know. If a suit is no good after six hours work that's one
expensive throw-away outfit if you ask me.

Good news.

According to this source, some of the suits used on the Mir were in
operation for more than 3 years.

I guess they're reusable then.

http://snipurl.com/ibqx

From: spacesettlers@yahoogroups.com
[mailto:spacesettlers@yahoogroups.com] On Behalf Of jwsmith42000@...

>
> > What's Damron?
>
> Sorry, that is Demron. Even at the end of a very long day I should not
be so sloppy. Try www.radshield.com
>
> > How can it be so effective? I didn't think chemical structure
could be so
> > important to high-energy radiation as to make two inches of plastic
as
> > effective as several feet of rock. Or does this plastic contain a
lot of some
> > heavy element?

Here's the disconnect: dsw_s is thinking about the radiation shielding
necessary to take care of cosmic rays i.e. heavy nuclei such as iron. I
note that the Demron site is talking about Beta's, Alpha's, X-rays, and
Gammas.

Regards,

Mike Combs

The active ingredients seem to be heavy elements, iodine and
barium. Here's the page linked as a reference by the Wikipedia
article on it

http://tinyurl.com/d6w56

I think those elements are rather rare on the moon.

I haven't read all the available information, but I'm not yet
convinced that this stuff is as effective as described against the
radiation that lunar and HEO residents will have to deal with.

Of course, there's also the question of what factor the radiation
needs to be attenuated by. It sounds nice to say 95%, but if you
need the radiation decreased by four orders of magnitude then 95%
doesn't do much good.

--- In spacesettlers@...m, cygonaut
>
> Yes, Demron's good.
>
> But can this be made from moon materials?
>
> You'd want a shielding you can make for your space suits yourself
rather
> than depend on costly launches from earth, I'm sure.
>
> On 10/9/05, jwsmith42000@a... wrote:
> >
> > dsw_s@y... writes:
> >
> > > What's Damron?
> >
> > Sorry, that is Demron. Even at the end of a very long day I
should not be
> > so
> > sloppy. Try www.radshield.com
> >
> > > How can it be so effective? I didn't think chemical structure
could be
> > so
> > > important to high-energy radiation as to make two inches of
plastic as
> > > effective as several feet of rock. Or does this plastic
contain a lot of
> > some
> > > heavy element?
> >
> > I can send you 3 pdf's that will answer that but you can easily
find them
> > now
> > that I have given you the right name.
> >
> > John Wayne
> >
t=ms&k=Science+kits&w1=Science+kits&w2=Science+education&w3=Science+k
it+for+kid&w4=History+of+space+exploration&w5=My+first+science+kit&w6
=Space+exploration&c=6&s=149&.sig=gTrCdYxE2q_EvQGIAV71Ag> Science
t=ms&k=Science+education&w1=Science+kits&w2=Science+education&w3=Scie
it&w6=Space+exploration&c=6&s=149&.sig=KrrU9QkAFWiVNpH7h9RtDw>
Science
+kit&w6=Space+exploration&c=6&s=149&.sig=W-7BEO8r3ZtoQ9jbs4CBTA>
History
t=ms&k=History+of+space+exploration&w1=Science+kits&w2=Science+educat
t+science+kit&w6=Space+exploration&c=6&s=149&.sig=HCnkutu-
WbqIdDyZ03N73A> My
t=ms&k=My+first+science+kit&w1=Science+kits&w2=Science+education&w3=S
e+kit&w6=Space+exploration&c=6&s=149&.sig=N-Ap7BxC283oYZFOVALO2w>
Space
t=ms&k=Space+exploration&w1=Science+kits&w2=Science+education&w3=Scie
it&w6=Space+exploration&c=6&s=149&.sig=3RuMQBQgzqtT7sV2N-JRQA>

space.action@... writes:

> John.
>
> John.
>
> The moon doesn't have it.

So you know what every atom on the moon (LUNA) is. I do not. Anyway I want
to talk to the people at this company face to face, and I will find out what
demron is made of.

> And mooncrete inside a spacesuit just isn't going to work.

Why do you say this? Who is talking about mooncrete except you. What will it
not work for? What will it work for?
Luna is way too close to Earth for my comfort. Luna is a worthless piece of
real estate except when I am walking with a pretty girl on my arm. I will never
be going to Luna any way. My goals are further out.

> Forget Aluminum.
>
Unfortunately I cannot do that. I make my money working with Aluminum.
The 16 person habitat which we are designing will have a one half inch
aluminum outer skin. The inner skin will be 1 1/2 inches of demron, 6 inches of
water and then another 1/2 inch of demron. The few interior walls will also be
made of demron. Interior supports will be aluminum. I doubt that I will forget
aluminum.

mikecombs@... writes:

> Here's the disconnect: dsw_s is thinking about the radiation shielding
> necessary to take care of cosmic rays i.e. heavy nuclei such as iron. I
> note that the Demron site is talking about Beta's, Alpha's, X-rays, and
> Gammas.
>
> Regards, Mike Combs

Good observation, thank you. What is good at stopping the heavy nuclei?
Have you read any of the information from the Voyager 1 about the radiation
near the termination barrier. I have not had time to even look at it.
Reports I have read suggest that all types of radiation is much stronger than
expected.

John Wayne

>What is good at stopping the heavy nuclei?<

As far as I know, the only two options are electromagnetic setups,
and just sheer quantity of matter. They can be used in combination,
because slowing down the high-Z particles makes matter much more
effective in blocking them.

If mass wins out, either on its own or in combination, I'm still
thinking the way to go is to have as much as possible of the
radiation shielding be functional parts of the colony. In
particular, as I've said, I think the agriculture should be
downstairs, because plants don't need the same level of protection
that permanent-resident humans do. (Same for vats of bacteria and
yeast living on synthetic small organic compounds, if that turns out
to be the way to go.) There may be purposes for which radiation is
actually useful: if water can be sterilized by radiation, for
example, water tanks downstairs can do double duty as shielding and
water treatment. For the people working in agriculture, there could
be a few slabs of five-foot-thick rock that can be moved around
under the floor so that a small area at a time is protected while
people are down there doing maintenance on the automated ag systems.

--- In spacesettlers@yahoogroups.com, jwsmith42000@a... wrote:
>
> mikecombs@t... writes:
>
> > Here's the disconnect: dsw_s is thinking about the radiation
shielding
> > necessary to take care of cosmic rays i.e. heavy nuclei such as
iron. I
> > note that the Demron site is talking about Beta's, Alpha's, X-
rays, and
> > Gammas.
> >
> > Regards, Mike Combs
>
> Good observation, thank you. What is good at stopping the heavy
nuclei?
> Have you read any of the information from the Voyager 1 about the
radiation
> near the termination barrier. I have not had time to even look at
it.
> Reports I have read suggest that all types of radiation is much
stronger than

Passive mass, electromagnetic, combination of those, or some other
technology?

If passive mass, will it be in its original form (i.e. dig out the
inside of an asteroid and live there) or will it be re-worked (e.g.
make basalt-fiber to bear the tension around the outside of a rotating
habitat, and have that be a major component of the mass shield)? Will
the shield rotate with the habitat, and have to bear its own
centrifugal weight? Or will it be separate, and have to have something
like an axle and bearings?

On Aug 19, 2007, at 17:20 UTC, Dan Wylie-Sears wrote:

> Passive mass, electromagnetic, combination of those, or some other
> technology?

Passive mass. A couple meters of dirt does the job, and you're going
to want a couple meters of dirt on the ground anyway -- otherwise it's
more "floor" than "ground." You want to be able to grow trees, plant
flagpoles, etc. So let's put a few meters of dirt down, and it will
both provide a nice basis for the biosphere, and provide radiation
shielding too.

Of course I'm assuming cylindrical colonies and artificial lighting,
where you're pretty much surrounded by the ground. If you insist on
big windows, then other techniques will be needed as well.

Best,
- Joe

Joe Strout -- joe@...
Strout Custom Solutions, LLC