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<br/>On July 18, 2013 at 12:13 AM Michael Turner <michael.eugene.turner@gmail.com> wrote:
<br/>
<br/>> > On July 17, 2013 at 7:14 PM Michael Turner <michael.eugene.turner@gmail.com>
<br/>> > wrote:
<br/>> >> .... Surely, if it's very efficient sky-to-Earth, it's no
<br/>> >> less efficient Earth-to-sky?
<br/>> >
<br/>>
<br/>> On Thu, Jul 18, 2013 at 10:57 AM, tme@asteroidinitiatives.com
<br/>> <tme@asteroidinitiatives.com> wrote:
<br/>> > I don't think so, for two reasons. One, the problem is not really symmetric.
<br/>> [....]
<br/>>
<br/>> OK, so it's like you have a distorting lens between source and target
<br/>> for a beam and you want to place it in the optimal position to reduce
<br/>> distortion. That'll be closer to the target.
<br/>>
<br/>> Beam dispersion and deflections that would be minor in going from the
<br/>> top of the atmosphere to the surface would be dramatic when going from
<br/>> the surface to the top of the atmosphere -- then out to GEO, tens of
<br/>> thousands of miles to turn, say, a 0.5 degree deflection into a wide
<br/>> miss of the orbital rectenna. Am I looking at the problem the right
<br/>> way?
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<p style="margin: 0px;">Exactly.  </p>
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>
<br/>> Maybe one workaround (kludgey, and only partial) is high-altitude
<br/>> microwave relay airships that feed off ground transmitters and output
<br/>> into GEO. But then you have a whole host of new engineering problems.
<br/>>
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<p style="margin: 0px;">It would probably be cheaper to move the entire thing to a high desert, like the Atacama desert of northern Chile, and </p>
<p style="margin: 0px;">do adoptive optics.  </p>
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<p style="margin: 0px;">Marshall  </p>
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> -michael
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