[ExI] Step at a time was economic parable
hkhenson at rogers.com
Fri Oct 10 04:00:07 UTC 2008
At 03:15 PM 10/9/2008, Jef wrote:
>On Thu, Oct 9, 2008 at 2:39 PM, hkhenson <hkhenson at rogers.com> wrote:
> > At 10:11 AM 10/9/2008, Jef wrote:
> >> For me, the biggest question not adequately addressed has to do with
> >> the extended ramifications of essentially single-point dependency on a
> >> particular geopolitical power in control of a major energy source.
> > What assumptions are you making to create this model?
> > There is zero risk the sun will stop shining.
>This wasn't any concern of mine, but thanks for the reassurance...
> > The rectennas are near power loads. The US alone will take hundreds of
> > power sats so failure of a few isn't going to be a major
> problem. They have
> > to be repairable since flying rocks will hit them once in a while.
>Of course there are multiple possible failure modes, and if you'd
>included sabotage it might have hinted in the direction of my
The rectennas are as vulnerable as any other part of the power
system, but being ten km across and highly modular it would be hard
to take out much of one by sabotage. The power sats are in GEO,
36,000 km out there. To the best of my knowledge nobody has yet
physically attacked a communication satellite. Not to say it
couldn't be done, but it wouldn't be a casual effort by a bunch of fanatics.
> > They could certainly be taken out with a large number of very large nuclear
> > weapons, but that's the same as all power systems on the ground.
>I imagine kinetic modes of (threatened) destruction would be nearly as
>effective, without the outright provocation entailed by a nuclear
>attack. My point was to the more subtle and insidious effects of,
>e.g., ostensibly unforeseeable "denial of service" events when a
>single agency holds the keys. Space is presently a militarily
>strategic "higher ground" which I don't imagine being easily
>surrendered to the "electric companies."
You have put your finger on one of the more interesting
problems. Oddly it's one that military people are most reluctant to
discuss. Kind of like the 800 pound gorilla in the room nobody will mention.
What may be the second least expensive way to get cargo into space is
"pop up and push" with an ablation laser. Energy wise a 4 GW laser is
equal to 1 ton TNT/sec. It would boil 480 gallons of water/sec. At
240 pounds per person and 8 pounds to the gallon, there is enough
power in a 4 GW beam to boil all the water in 16 people in a
second. At least you don't have to worry about eye protection!
Used for propulsion the beam power would be focused in about 8 sq
meters or a power density up to boiling 60 gal/sec/m^2. A standing
person considered as a 2 meter tall block massing 200kg would have an
area of 1/10 square meter. So the beam would boil 6 gallons off the
top of this block or 48 pounds.
So being touched for a second with a 4 GW propulsion laser would
*not* completely vaporize a person, but would boil them away down to
mid chest . . . unless they were wearing their tin foil hat . . . .
(Note to self, invest in companies that make tin foil hats.)
A propulsion laser uses very high pulse intensity--like lasers used
to reshape a person's eyes. It's possible not much heat damage would
be done below where the beam blasted away flesh. Except from the
pavement all around them being blasted into incandescent vapor.
Any one of hundreds, then thousands, of multi GW power satellites can
be converted to powering such a laser.
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