Over some while thinking about it, I've arrived at my
own view of how to go about building off-Terra lifespaces
and settlements. It was really obvious, but I was a
while getting there. When I thought of my pickle jar
test, was when for me it fell into a definite focus.

The question is, what do you build your habitable
structures out of? Remembering that empty space is a
totally hostile environment? So you need durability
and fail-safe?

And I thought, well, if you stand on a concrete floor
with a can of evaporated milk in one hand and a glass
jar of pickles in the other; and you drop these, what
happens?

The pickle jar shatters. The can gets dented but does
not leak. Thus I've arrived at my strong conclusion
that my settlement architecture is based upon soft
sheet iron, which can be made by an iron carbonyl
process without molten metal ladles, a rolling mill,
and etc.