The need to conserve

--- In spacesettlers@yahoogroups.com, sraj wrote:
>
> A good thing about travel on our planet is that it does not as a
whole lose mass each time people travel in a jet from London to
Shanghai. In Space Habs on the other hand the situation will be
dramatically different. Any movement, any thruster firing will result
in a loss of mass from the composite system - irrevocably lost.
Slimming down will be no problem in Space Habs : - )
>

if your talking about going traveling between two points inside the
same structure, there would be little difference between doing the
same thing on earth. the one difference is that if there is a large
movement of people and goods in one direction there needs to be a
movement of some kind of ballast like water in the other directions.
this would limit the amount of thruster firing needed. also some of
the changing in speed of rotation or wobble could be taken care of
internally. If the structure was rotating inside a non-rotating
structure, it could handle the changes then us other methods of
balancing its delta v change. all of this would diminish any need for
thruster fire. in addition to this is the possibility of capturing
solar wind (slight as the amount of particles are, capturing what
hits over a large area would add up) to use as thruster propellant.

>
> Based on this rather unpalatable fact we can arrive at some dos and
don'ts for an aspiring space based civilization.
>
> 1. Conserve, conserve, conserve. Recycle, Recycle, Recycle.

goes without saying.

> 2. Invest in technologies to achieve max exhaust velocities in all
thruster and rocket propulsion systems. Energy from the sun is
limitless, but mass lying around in non-gravity-wells is not.

there was an article on planetary chauvinism linked from one of these
threads. you should read it. basically, there is so much more
material in the solar system that is outside of any gravity well
(other than the suns of course) in this solar system than there is on
earth. it would be easier to gather that and bring it to earth than
to bring it from earth.

> 3. Don't make the same mistake we made on our planet. Plan for a
modest population in Space Habs. There have been projections of a
trillion people living in space habs. Let's keep the number more
manageable. Ten billion let us say.

its been calculated that the material in one of the largest asteroids
could give many times the surface area of earth. on the other hand
we do need to slow the increase but stopping it all together would
not be necessary.

> 4. If there is to be trade between two civilizations separated by
large distances, it should be kept modest and focus only on high
value goods.

that depends on what you use for your ship. using rocket fuel would
never be a good idea, but using material from space, esp something
like photons from the sun, would make it workable, but slow.

> 5. Basically it would be wiser for populations which move out to
simply forget about their home country, to devise their own
civilizations and not look back. Just the way it used to be in
earlier times on Earth.

that would not be human civilization then. it would also be extremely
dangerous. the end result would be two completely different species
of beings, which being of human extract, would certainly lead to
fighting between them.

>
> Globalization is space is actually as meaningless as it is on our
own planet (for other reasons).
>

globalization of earth is a accomplished fact. not a meaningless one.
its would eventually be the same for any civilization that was based
on earth, and orbited the earth. IF we ever get a much more practicle
for of transportation (such as they suggest will happen with star
trek) then "globalization of the solar system will happen.

>
> Based on this limitation we need to rethink some of our present
ideas on space colonization in the NEAR future:
>
> 1. Habs on / near Moon: Joe rightly pointed out that hydrogen,
which is not available on the Moon can as well be taken from Earth.
And carbon too, since we are not too fond of it at the moment. The
fact that we are living in a gravity well is one aspect of the
problem. But the advantage is we can go on firing as many LOX /
hydrogen propulsion rockets as we wish to.

no actually we cant. just because the condition of the earth is the
best for humanity at this time, this does not mean that this is the
way the earth will always be. we are still in the clutches of an ice
age (polar ice caps dont exist outside of one) and one day the earth
will reballace itself to a higher tempature. humans, being human,
have the ability to adapt to the higher temp. many creatures do not
have that ability, but life does.
>
> 2. There have been some discussions on going to the Moon before
going to Mars. Now I too am wondering, why not go to Mars directly if
we plan to go there: with support facilities (modestly sized rotating
space habs?) in orbit around Earth.

several reasons. one is that you can use the moon for a launching
platform. one of the suggestion for sending a ship to mars would have
much of the material, including some of the fuel, fired from long
electromagnetic rails on the moon, to a speed sufficent to get it
beyound the speed of earths gravity. If the materials were
manufactured on the moon and fired into excape velocity using this
method, there would be little need for fuel for the resupply rocket,
save for landing on mar. one suggestion even has solar sails to slow
down into capture speed, so that supplies used in orbit or to fuel
the landers would not need fuel at all.

another is that there is a large group of people on earth that want
to have a permanite base on the moon. satisfying this desire will
allow a large amount of other things.

>
> 3. The enabling thing will be cheap and giant sized LOX / hydrogen
propulsion rockets. Plenty of them.
>
LOX/hydrogen rockets are not that efficent. there sould be much
better ways of going to mars. that way we can keep the o2 and h2 for
water for the future civilizations.