[ExI] How will air travel work in a green solar economy?

[Robert G Kennedy III, PE]

Keith Henson replied to John Clark:

> I don't know about getting power from L1, might be possible, might
> cost too much, but in any case, sunshades are a good idea even 
> without
> energy from them.  The best part is that they can be reconfigured to
> warm the earth as well as cool it.

Yes, one of our selling points is that the scheme is reversible.

> The only problem I see with Dyson Dots is the amount of material
> needed, in the hundreds of millions of tons.  That large even in the
> context of a power satellite project big enough to completely 
> displace
> coal an oil.  However, if we build the last half of the power
> satellites with material from the asteroids, then we can keep the
> mines going a few more decades and have all we need.

Yes, hundreds of Mt. Other than a first prototype article, we're not 
thinking of boosting any of it off Earth. Too dang expensive. For a 
project of this scale, it's off-world materials or nothing.

Now, I will concede that 2/3 of that mass in space is driven by the 
power generation function we're piggybacking on the sunshade function.

Robert