Using Concrete to build space ships...

--- In ssi_list@... "Valens Agnitio"

> Because of the masses involved, I don't think ion thrusters would
> work. If we are looking at bringing in several hundred thousand
> tons, what would an ion engine have to be like to move it in a
> reasonable amount of time?

> Val

I've been watching this thread unfold and I'm really curious about
something. When Frank started it he conceded that there were a
number of drawbacks but he wanted to look at some potential benefits.

OK.

But now conversations are turning to propulsion and I'm wondering
why no one has brought up the rocket equation.

Building a spaceship from concrete will necessitate carrying more
fuel to propel the ship. One would want to have the lowest dry mass
possible. Radiation shielding could be achieved internally with
hollow cylindrical tanks of water that double as repositories for
ship water needs. There is no need to build up the mass of the ship
with concrete for radiation protection.

Are you guys seeing something that I'm missing?

TangoMan