Re: DIY space transport

"George William Herbert" <gherbert@xxxxxxxxx> wrote in message
news:11djf3t9h3r2le4@xxxxxxxxxxxxxxxxxxxxx
>
> I am nearly done with the first draft of a rather long piece
> for The Space Review [sorry, to several reveiwers here
> who I initially said I thought I would get it to 10 days ago-
> ish] which is a rebuttal to an article they had a few weeks
> ago that argued that only large module space stations are
> viable.
>
> 2-ton modules are sort of small. Five ton modules...
> appear to be on the good side of the efficiency knee in the
> overall graph.
>
> In some ways, five ton module stations may be more cost
> effective than ten or twenty or one hundred ton stations;
> they will weigh moderately more than 20 ton and up
> module based stations, but for nearterm station concepts
> the launch cost is rather far down in the noise. And most
> of the stuff which makes more smaller modules seem more
> expensive vanishes or inverts if you study it hard enough.
>
> Getting to the point that it is no longer a trivial side factor
> is a major goal of serious space development.

Even this seems to assume an inflexible pre-furnished module approach,
not a bare shell approach that one then moves furnishings into. Kind of
like buying a fully furnished caravan and then trying to attach it as
one unit onto the side of a house, instead of buying a shell of a room
and then adding light weight furnishings to taste.

Assuming a kitset approach, where furnishings are moved in post module
connection, how heavy would the largest one piece components be? Items
above a few hundred kilograms would seem inconvenient to access,
maintain and rearrange. Beyond habitat shells what wants to be in one
piece and heavier than this? Solar arrays? It would seem to me that
these would want to be modular anyway and could be added in the same
fashion as habitat modules.

Even a three metre diameter by five metre long double shell foam core
carbon fibre habitat shell need only weigh a few hundred kilograms.
Throwing a light weight impact resisting multi layer fabric tent over
such a shell seems fairly trivial.

Why is furnishing a bare habitat shell in space such an onerous task
that must be avoided?

Pete.


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