[ExI] Lack of interest

[hkhenson]

At 06:10 PM 5/8/2008, Bryan wrote:
>On Thu, May 8, 2008 at 1:06 AM, Damien Sullivan
><phoenix at ugcs.caltech.edu> wrote:
> >> What we really need to do is come up with a way that provides
> >> renewable energy at a lower cost than coal and oil.  I think there is
> >> such a way.  Anyone interested in seeing work on it should send me
> >> email.  No point in sending it to the uninterested on the list.
> >
> > I'd say just send it to the list.  As on topic as anything else going
> > on.  Tough goal, though, to compete with high-quality fuel we can just
> > slurp freely out of the ground.
>
>Why compete with it?  As for Keith's question, I have a few pages up
>on my site that might eventually do the trick. I want orbital algae
>farms for getting solar energy, with bioharvesting approaches there,
>solar powered satellites, solar array farms, etc. But all of these
>require space-based manufacturing approaches, and that's what we can
>focus on first, like asteroid mining,

Stop right there.

Look I *founded* the L5 Society.  If there is anyone who is going to 
defend going after ET materials it's me.

The problem is paying for it.  As Freeman Dyson noted in _Distrubing 
the Universe_ the cost of going into space is 10,000 times to high 
for us to do it on our own.

That means we have to figure out a way to get there on things (like 
energy) that other people want.

The problem with extra terrestrial resources is that we are not going 
to be able to make a case before funding sources for them.  The time 
line is too long and the risk is too high in the viewpoint of funding 
sources.  That's just the way it is.  Phil Chapman commented on this recently.

I got into this study backwards, from working on space 
elevators.  Now if you have a high capacity, moving cable, space 
elevator you don't need extra terrestrial resources to do massive 
projects in space.  The lift energy payback for an SPS taken into 
space with an elevator is *less than a day.*  But it turns out 
rockets are not as inefficient as I thought.  It takes under 20 days 
for an SPS lifted into space by rockets to pay back the lift 
energy.  That's good because we don't have the nanotube cable to make 
space elevators yet and we might not get it pre singularity.

I don't think humans will get into space in significant number pre 
singularity and afterwards who knows?  But unless the singularity 
comes in the next few years, the energy crisis is going to cause 
billions of people to die.  I can make a case for replacing oil with 
solar power satellites lifted by rockets in less than a decade.  I 
can't make a case for asteroid resources.

If you want to convince me you can, put numbers on your proposals.

snip

Keith Henson