Digest 1105 Msg 7

>At the moment what we are lacking the most are the
>right motivations and economic feasibility of space
>settlements
>With existing technology , at 10000$\Kg in LEO, no
>plans are possible.

So should we sit on our thumbs until the kg launch-costs are down to
that level? This might need a long time.

Why not just use the capacity we are having already to go forward and
do some things we are able to do now, getting a head start when the
launch price has come down too?

What would we need first to build habitats? Materials already located
in space which we could extract best outside of a heavy gravitation
well - off Athens group Near Earth asteroids, were we have lots of
energy not only for power generation but for cheap solar sail
propulsion also.

You dont have to put fuel into space for acceleration gained from
solar light pressure.

If we start to place one or more solar sail motherships into space we
had the interplanetary transport infra structure already in place and
probably also the infra structure to mine those asteroids and bring
the materials back to Earth orbit.

If you take a look onto the links at the end of this message youll
find a solar sail design with an possible earth weight of about 15
tons with a docking and payload station of about 22000 m^3 volume to
take on several landers, flying ore containers and satellites to
provide earth like space navigation and observation for asteroid
mining operations.

Moreover the solar cell arrays located around the docking station
could deliver power for a mobile laser daughter unit for melting and
probably processing materials directly at the asteroid.

>If you consider that to put 10 people in LEO with the
>shuttle the cost is about 400MIL$ that makes
>40MIL\PERSON in LEO only
>TO GO TO L5 AS AN EXAMPLE ADD ANOTHER 20mil\person,
>which is a very conservative figure, and you would
>have a 60mil$ per person just for transportation.

I would look first to the immediate costs to put the ISS which was
already pay ed for to a good use.

For the mothership we would need to howl 20 tons of construction
materials into space (15 tons for the mother ship another 5 tons for
construction equipment) and than let 10 astronauts work one year on
the construction we would need 200 million to get those 20 tons into
space and say one billion for those 10 astronaut years plus further
development and construction costs on Earth.

With about 2 billion this comes not cheap but is very feasible for the
community of countries which support the ISS.

>for 1000colonists means 60B$ for the 10000 as envision
>by ONeill is 600B
>Does this make any sense?
>So let's go back to reality and see the entire
>operation from a strategic point of view
>Priority one, is to slash transportation costs to LEO
>to no more than 100$\KG.

Priority one for me would be to get to asteroids for material
extraction and transport into Earth orbit.

>With such capability the space frontier will at last
>open up to private entrepeneurs, Mars missions, space
>tourism, lunar bases and so on.
>How we go from LEO to other desired locations at an
>affordable cost?
>By deflecting asteroids, put them in cycler
>trajectories between earth and the main destinations,
>equip them with a space station type of facility and
>utilize their resources for life support activities,
>including fuel for shuttle between the cyclers and the
>final destination and we have a nearly cost free
>cruise ship .

Why would we deflect a big asteroid first? A big asteroid is quite a
lot of mass we cant handle for a long time.

We have to mine that asteroid anyway, if in Earth orbit or in its
original orbit.

But we could just take away those materials we need in the moment or
the materials we could get away with one cargo load and bring just
that back to Earth saving to accelerate the huge rest of the asteroid.

When the transportation is mainly free through free solar pressure
propulsion, why would we need to waste precious asteroid materials for
propulsion?

>Only after we have such a capability, we can start
>seriusly talking about space settlements and their
>economic feasibility, prepare business plans and
>define the motivations for their construction.
>In the meantime we can update the settlement design
>with state of the art concepts,such as defining the
>design goals, flexibility, modularity, expansion
>capability, asteroid as material source, allowing any
>solar system location and so on.
>The final goal must not be a few small space
>settlements but in the long range the capability of
>mankind to leave their planet of origin and expand in
>space, first in the solar system later in interstellar
>space

I would agree here.

Frank

www.solar-thruster-sailor.info

For the first solar sail design of a carrier ship with
docking able
landers and with roller reefing

making it possible to leave the atmospheric drag zone
near a space
station and getting back again delivering asteroidal
ore to that
Near Earth space station

take a look at:

www.solar-thruster-sailor.info/figs/fig13.html

http://www.solar-thruster-sailor.info/figs/fig14-15.html

http://www.solar-thruster-sailor.info/figs/fig17.html