Using Concrete to build space ships...

--- In ssi_list@... "victoriatangoman"
> --- In ssi_list@... "victoriatangoman"
>
> > You may say that you'll use a high efficiency Ion Engine with a
> > high ISP. OK. Where will you get 56,400 tons of Xenon? From
Earth.
> > You'll have to launch it from Earth and now you're once again
> > confronted with the Rocket Equation. Your Xenon payload, on
a
> > rocket powered with LO2/H2 will be only 10% of the GLOW (GROSS
> > LIFT-OFF WEIGHT) at best.
>
> How many launches will you need to launch 56,000 tons of Xenon to
> LEO?
>
> If you use the Atlas V, you'll need over 2,500 launchs.
>
> Of course you're free to use other vehicles - I just chose the
Atlas
> V because it was convenient.
>
> Here is the data for the Atlas V:
> http://www.astronautix.com/lvs/atlasv.htm
>
> Here is data for other launch vehicles, so that you can chose one
> that is more appropriate to your mission:
> http://www.astronautix.com/lvs/orbindex.htm
>
> How much air will have to liquified to extract the Xenon and how
> much will it cost? Here is a quick and dirty reference:
> http://www.ktf-split.hr/periodni/en/xe.html
>
http://www.chemistry.pomona.edu/Chemistry/periodic_table/Elements/Xen
> on/xenon.htm
>
> TangoMan

Concrete is an excellent building material. it is strong, offers
excellent radiation protection and we have allot of experience
working with concrete. We understand it physical properties and
limitations. As man continues to move into space, we will also use
concrete when appropriate.

For structures on the moon and mars I believe that it is an obvious
choice. Assuming that there is a source of calcium available that is
not too toughly bonded in minerals such as plagioclase feldspar. On
Earth we use limestone or CaCO3 (calcite). as fare as we know
limestone is unique to earth because it is formed by the marine
organisms. The are a situations on earth where non-biological
precipitation of calcite occurs such as oolites and travertine. I
would not be very surprised to fine calcite on mars for example.
But, I would be surprised to find calcite on the moon. There have
been studies that demonstrated calcium oxide can be extracted form
glass forming around craters on the moon. This is good news, but it
is also a material process that has not been tested.

For spaceships, concrete is heavy. I believe the mass issue is less
of a concern than Tango man has indicated. If we build a cycle for
sending colonist to mars, it will be massive. whether it is made of
iron, cast basalt, or concrete, it will have considerable mass. Even
if it was built out of aluminum or titanium, it would be massive
enough that blasting it into the cyclic orbit would a great expense.

The trick is to build the cycle out of material that is in an orbit
closer to the orbit that we need. That way the amount of deltav can
be reduced.

Jeffrey