Asteroid use

Marcel,

This isn't getting us anywhere, we're just going round and round to
start all over again. For the record, personally, I'm all for any
kind of development of space resources, be they planet based or
asteroid based or something else. That said, I'm of the opinion that
while all avenues should be explored and used, the one with most to
offer in terms of cultural variation and human development is the
large rotating orbital habitat, until something better comes along.
Having said this I would also want to see the development of
planetary surfaces but if you start putting people in large numbers
there, they will begin to object when I want to start ripping up that
surface to get to the goodies that nature hid there.

Now about putting large and small masses into Cis-lunar space.

DB.
> On the other hand the small loads of rock
> attached to light
> sails would require a less effort to change course
> at the last
> moment, a LOT less, a million times less. I feel
> safe with big
> rocks, little rocks make me a little uneasy.

MW: The solution is to keep the little rocks and the
big rocks out of the Terra-Luna system and as we say
in America 'Let Sleeping Dogs Lie'.

DB: "Let Sleeping Dogs Lie"? With that philosophy you would be still
living in caves or have horse drawn carts and gas lights. Ignoring a
problem does not remove it, all it does is make sure you don't see it
as it hits you in the head. You advocate sending shipments of cargo
from Mars to Earth. How is 10,000 tonnes of manufactured goods any
less massive or for that matter any less of a threat than 10,000
tonnes of rock? Which one is lighter a pound of feathers or a pound
of steel? If you sent a shipping container or even a convoy of many
of them, filled with goods with a mass of 10,000 tonnes each (this
works even better with smaller masses) from Mars to Earth and then as
it/they swing in close to Earth to bleed off speed before moving into
a parking orbit you fire a motor hidden in the cargo and the
container/s coated in it's ablative shielding enters the atmosphere
before hitting the ground at a speed of 20 Km/Sec, turning the city
of (insert the city of your choice here) into a smoking ruin. How
hard is this to do? Well as others have said, not easy, but it is
doable. Time from start to finish? Well, from months to years
depending on how you move it.

DB: On the other hand I use light-sails, plasma drive, ion drive,
bolt on mass driver or what ever I have to begin to move a very large
and massive rock from the main belt or even better from an Earth
crossing orbit. I give it small, well timed nudges to move it to
where I want it. The full fight plan would have been worked out long
in advance and announced to the world, I have nothing to hid. After
years or even decades the rock edges up to Earth, now as it closes it
would be moving at a crawl. Why? Because it takes a lot of energy
to slow down and the faster it moves the harder it is to stop, the
slower it moves, the safer it is to people on the ground and if it
doesn't follow the public flight path, well people will have a lot of
time to fix the problem or me at lest. By the time the rock is
reaching it's destination it has maybe passed Earth a few times and
swung pass Mars and maybe even Venus, with a final swing pass the
Moon. Now if I had it moving in to its final orbit and as it swings
pass Earth (if I'm allowed to do that) I fire off a rocket with the
intention of crashing it into a city/country, I have a huge effort in
store. If the best I could do to move such a mass takes years to
move it from start to finish, then I couldn't push it hard enough to
crash it or if I could the I wouldn't need to, I'd have the
technology to hit them in a cheaper way. The other problem is your
small masses (relatively) will be coming with great frequency, one
per day, one per hour, ten per hour, a convoy of a hundred? My large
mass would be only once in maybe a decade or maybe even longer for a
large mass. Yours is hard to keep track of, mine is easy. Bottom
line, big is safe, small is a potential weapon.

Where have I gone wrong?

> Darren Brown: Next, Mars Vs Asteroid.
>
> Sorry Marcel, you have the cart before the horse.
> You have a couple
> of problems, first, the delta V needed to move a
> rock from the main
> belt to Mars orbit is more than what is needed to
> move about in the
> belt. The hook here is the time needed to move
> about the belt but
> this is offset by the fact that you could manage to
> have lots of
> rocks on the move at once and so could arrange a
> steady supply of raw
> material to a given point, Ceres if you like or any
> other rock that
> takes your fancy.
MW: But you forget, that eventually the processed mass
in the asteroid belt has to eventually end up in the
Terra-Luna system. But if your goal is to process
material in the asteroid belt solely for folks who
live in the asteroid belt then you'd have a point.

DB: I'm sorry, maybe I wasn't clear enough. You want to get your
raw materials from both Mars and Asteroidal sources, right? That is
what the light-sails were for? Okay, in that case, I wanted to know
why? You, are talking about two moves, one from the belt and one
from Mars surface to Mars orbit, where your factories are and then
after processing being sent to Earth. I was saying that you can get
all of your needed materials from non-planetary sources and will need
less energy to move them from source to factory. You still then have
to move them to Earth. Now, depending on your method, you may find
that transport costs are insignificant but I think while this may be
true for orbit to orbit movements, this will not be the case for
surface to orbit movements, such as Mars to orbit. Of course this is
predicated on having your factories out at the source of your
materials. If I've moved my very large mass into an L4 orbit then
all comparisons are moot. My workforce is happy living in Island 3
and working on the large rock we've just moved in next door. When
ever you talk about doing things in space you must remember the
golden rule, once you are in Earth orbit, your half way to
everywhere. Going back down to a planets surface is just crazy, it's
like driving with the brakes on!! Even using robotic equipment with
tele-present operators, Mars makes no sense, you could do the same
from Earth to Earth orbit and I think I shown that you can move your
raw materials into a safe orbit.

Darren Brown: A few times you have mentioned
> that Mars has all
> the materials needed to build a base so you could
> live off the land
> while building your infrastructure. What can you
> obtain from the
> Martian (I'm not sure about Marsian, I have never
> heard it before, is
> it something new?) resources that you can not get
> from asteroids or
> comets? Answer, nothing!

MW; Again, because of its significantly larger gravity
it is much easier to live on the surface of Mars than
it is to live on the surface of an asteroid.
Microgravity environments are already known to turn
off the immune system and to deplete calcium in the
bones. And the gravity of Ceres is significantly lower
than on the Earth's moon. Your health cost and your
labor cost are going to be very high compared to
someone working on the surface of Mars.

DB: Please, this not the question I asked. Again, I ask, what
resource can you get from Mars that you can not obtain from non-
planetary sources?

DB: As for your point about gravity, we don't know if 1/3 G over the
long term is any better than micro G. It is possible that people can
no more live in 1/3 G for a long period without health risk than they
can in micro G. For my part I think it would make a difference but
it may have other effects that we don't know about, maybe 1/3 G is
okay for years or maybe forever, there is only one way to find out
and I want us to know but that is a different from setting up house
on Mars. But as for my workforce, I never considered that they would
live on the surface of the asteroid, however you are very wrong about
the surface of a large asteroid being the same as micro G. The NEAR
probe is in orbit around Eros, how do you do that in Micro G? There
is very much an up and down, you can just overcome it with ease.
This does raise a very good question though, if the, let's say 1/50 G
of Ceres (I'm not sure that it is 1/50 but it's a good a number as
any for this point) is not able to keep people healthy but the 1/3 G
of Mars is, where is the cut off point? Personally I don't think
there is one, just that some people will be able to take lower G
without trouble for longer than others and that anything less than 1G
will cause problems for some while other will benefit from less than
1 G. But I wasn't going to put my workforce on the asteroid surface
anyway so this is of academic interest only.

Darren Brown: Your other big problem is
> a legal one,
> forget your ignorant masses the problem is in a few
> UN treaties, they
> stop you from claiming any celestial body. You
> start digging up Mars
> to build your bases and you will find researchers
> running around
> yelling for blood. They will point to you
> contaminating the
> environment and ruining the research possibilities.

MW: Since researches would need to have a base in
order to survive on Mars in the first place that would
be like saying "Please kill me, I shouldn't be here."
Besides I believe that there should be an
international 'Natural Wonder' law that does not allow
and country or business to exploit or to lease more
than 1% of the surface area of a planet or an asteroid
100 kilometers in diameter. And even on tiny Ceres
that would mean that several thousand square
kilometers of surface area would be available for
exploitation. And with the exception of the Earth
grazers, I see no reason to exploit asteroids larger
than 2 kilometers in diameter and smaller than 100
kilometers in diameter. These are natural wonders
that should be left alone, IMO. The limited
exploitation of the largest asteroids and the billions
of smaller asteroids that range from 1000 tonnes to
over a billion tonnes each should be enough to build
all of the space colonies that we'll ever need in the
solar system.

DB: True researchers work in the Antarctic without problems but they
also don't open mines. Is there a difference between an operation
that has a Mars with 10 research bases and an operation that has a
Mars with 10 research bases and 20 mines? Having research bases and
having mining operations are very different. Mind you, I think Mars
should be allowed to be mined, providing there is no special reason
not to. If you landed your expedition and found life there, we have
a major ethical problem, do we have the right to upset the
environment containing a native life form? How long do we have to
look before we can say there are no native life forms? How do we
keep our life forms from contaminating the local environment? These
are questions that really should not rise with respect to asteroids,
at lest not as we understand things at the moment.

DB: A natural wonder law? Please tell me you are kidding! Your
limits are arbitrary and without any reason other than people like
round numbers. Why 2 Kms and 100 Kms? If a particular rock has some
kind of merit or there is something special about it, fine, there are
lots more out there but just because it's less than 100 Kms wide?
Chances are that a billion years ago it was more than 100 Kms wide
but time has chipped it down to size, I can't use it just because I
wasn't around a billion years ago or how about I see a 20 Km wide
rock that I want, if I throw a few 200 metre rocks at it can I use
the parts I chip off, they should be smaller that 2 Kms and if not
I'll just keep throwing rocks until it is. Madness.

> By the way, in reference to a comment made in an
> earlier post, living
> in a mine is not a bad thing, there are a number of
> places in
> Australia where this is what people do, the surface
> is much too hot
> for comfort so the population have moved underground
> into very nice,
> comfortable houses cut from the rock, very safe,
> very pleasant, I
> have spent time in one, albeit a short time.
>
MW: I'm sure that there are people on this forum who
would love to live there :-).

DB: It's not for me, much to hot, I prefer cooler climes but it does
illustrate a point. Why do these people live in holes in the
ground? Because it is comfortable and suits the place they are
living. Now when I say a hole in the ground I don't want you to
think of a dark, dank, wet mine with the ever present threat of cave-
in. these places are comfortable, light, houses, homes really. They
have electricity, running water and all the normal things you would
expect to find in a modern house with the exception of windows. The
people there were presented with a problem and they solved it and the
solution is a very good one.

Darren Brown.