HOST Comp JimS wrote:

I would like to know why we don't travel to Mars
by first lifting many loads of fuel to the space
station. The actual spaceship would be assembled
in space... 20 to 50 trips would be necessary...

Perhaps something like that will be done someday, but
there are some disadvantages. For one thing, storing
tons of flammable fuel at a space station might be somewhat
dangerous. Also, assembling things in space is a slow,
difficult process. And the cost of making 20 to 50 trips
would be huge.

But how does the cost, and time, compare with making one trip with 20 to
50 times the total mass? Can we even do it? It needs a detailed
systems study, which probably has already been done. If not, why not?
If so, I would like to know the results.

I think the fuel danger is not excessive. The fuel containers could be
kept at a considerable distance from the station, on a wire heading
toward the earth. Tidal forces would keep the wire taught. That might
be necessary if they were solid fuel, which could explode if hit by a
micro-meteorite.

OTOH, if the fuel was two components, say oxygen and hydrogen, then
neither oxygen tanks not hydrogen tanks are explosive on their own. To
keep them cold in space mainly requires sheilding from sunlight.

m

--
"Many are stubborn in pursuit of the path they have chosen, few in
pursuit of the goal." - Friedrich Nietzsche

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