Tensegrity Structuspace habitats

> Just skimmed through it. It will take some serious free time to work
> through. This design is similar to my preferred design which puts all
> extraneous shield mass on the outside (not or slowly rotating).

I have mixed feelings about that. Certainly it's not needed in LEO, but
in free space, you do need somewhere in the neighborhood of 10 tons/m^2
of shielding. I do see the advantage of not having to support that
against the artificial gravity.

> However,
> I have decided since attending the indoor agricultural conference last
> year that going through the convolutions required to get sunlight into
> growing space just isn't worth it. It is a moot point in indoor
> agricultural now. Yes there are still glass greenhouses but they are
> being supplanted by LEDs inside closed highly insulated buildings. More
> control. Less variance.

Yes, that's my reading of the tea leaves too. As a result, I think
we're going to see more and more growing of produce near the point of
sale; as soon as you move agriculture indoors, trifling things like
climate and day length just don't matter, so it will be cheaper to grow
stuff where it's sold than to ship it all by plane/boat/truck every day.
And this is a very healthy development, with obvious application to
space settlements.

> I did notice that the study seemed to put
> control of the torus spin in the slow counter rotating outside mass
> instead of in the hub: Good Idea.

As far as this goes, I think you'll always want to have zero net angular
momentum if possible, for several reasons -- including the ability to
spin up (and down) your habitat without using propellant.

So if you have a heavy external shield, then absolutely, it makes sense
to push against that to spin the habitat. Or, if you have two rotating
habitation sections, then you can spin them up together. In either
case, it requires only electric motors.

I can well imagine an early-stage design (e.g. Kalpana One) might not
have a convenient mass to spin the other way, though. The hub doesn't
count, because you really want that to be stationary for docking
purposes. In this case there will be no alternative to using
thrusters... though they could probably be some very efficient type,
like ion engines.

Best,
- Joe