[ExI] global warming again.

Keith Henson hkeithhenson at gmail.com
Thu Mar 19 21:49:09 UTC 2009

2009/3/19 Stefano Vaj <stefano.vaj at gmail.com>:
> On Thu, Mar 19, 2009 at 8:22 PM, Keith Henson <hkeithhenson at gmail.com>
> wrote:
>> Space based solar provisionally looks like the best idea.  Going to
>> much higher exhaust velocity than you can get with chemical fuels for
>> the second stage seems to be one way to get the cost to GEO below
>> $100/kg.  That's low enough for penny a kWh electricity and synthetic
>> liquid fuels for a dollar a gallon, but it only works for a million
>> tonne per year traffic model.
> What about a Project Orion vehicle?

Do you want this to happen?  GW lasers are bad enough.  Hitching power
satellites to the use of nuclear bombs strikes me as a way to fail.
Personally I would rather see 10,000 nuclear reactors for power than
using bombs to launch power sat parts.  I simply don't believe you can
launch projectiles with 5 Mt bombs and not get a huge buildup of
radioactives in the atmosphere.  Also, I think we need a lot of people
in space to assemble power sats and there is no way people are going
to go into space this way.

Besides, at $100/kg reducing the transport cost to zero will only cut
the cost of power by half.

The difference between half penny and penny a kWh generating cost
hardly shows up in electric bills, and it makes little difference even
in the cost of synthetic gasoline because at that price a lot of the
cost is in the capital for the synthetic fuel plants.


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