[ExI] global warming again.

Keith Henson hkeithhenson at gmail.com
Fri Mar 20 19:11:06 UTC 2009

On Fri, Mar 20, 2009 at 11:39 AM, painlord2k at libero.it
<painlord2k at libero.it> wrote:


> There is no need of a 4 GW laser cannon to put in orbit a SPS system.
> You only need a Few launch of large missiles in LEO with the stuff needed to
> build a Space Elevator.

You are seriously misinformed.  You have to be at GEO to build an
elevator.  Also we don't have the material for it and my never get it.

> The materials needed for the cable are in the development phase.
> After the basic SE is in place, you reinforce it until is large enough to
> put significative payloads in GEO. Then you build a second and a third SE
> (to redundancy). Then you put in GEO whatever you like.
> A few MW class LASERs could be useful to put in orbit a continual stream of
> low weight payloads to feed the construction of the SE with bulk materials,
> to transfer energy to the climbers motor, to push the climber itself up and

It takes 15kWh/kg.  100 t, 100,000kg x 15kWh/h is 1.5 GW.  So a moving
cable space elevator would need a 1.5 GW motor to power it.  The
electrical in to potential energy gained is about 10% for climbers so
you would need a laser with a 15 GW input for climbers.  Climbers make
no sense because you can lift as much with half as much ablation
propulsion lasers.

> to deorbit the trash in orbit (shoot them with a powerful enough LASER and
> the ttrash will be vaporized or will be slowed enough to fall down in the
> atmosphere.

This is the one use that megawatt scale lasers have.  And that's
marginal.  You really need them in the tens of MW.
>> I suppose I should mention Orion in power sat transportation talks.
>> It would take launching a mid sized Orion--using over 1000
>> bombs--every day to transport the materials needed for power sat
>> production.  Big lasers look safe and sane in that context.
> http://nextbigfuture.com have a few articles about Orion and its viability.
> The only sane motive to not implement it is that people would go insane
> about inconsistent fears.

I have a relative who was downwind of one of the underground shots
that failed to stay contained.  Chances are fair they will die from
the effects.


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