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From: chiaraviglio@husc2.UUCP (lucius)
Newsgroups: sci.space
Subject: Re: Powersats
Message-ID: <1007@husc2.UUCP>
Date: Sun, 2-Nov-86 01:27:37 EST
Article-I.D.: husc2.1007
Posted: Sun Nov  2 01:27:37 1986
Date-Received: Tue, 4-Nov-86 00:49:45 EST
References: <531179395.amon@h.cs.cmu.edu> <1575@jade.BERKELEY.EDU>
Organization: Harvard Univ. Science Ctr., Cambridge, MA
Lines: 25
Summary: Phase conjugation runs into problems when the round-trip time for light becomes significantly long compared to the rate of ch

In article <1575@jade.BERKELEY.EDU>, c60a-2jm@tart23.BERKELEY.EDU (Adam J. Richter;260E;;) writes:
[Reference to _S_c_i_e_n_t_i_f_i_c _A_m_e_r_i_c_a_n article, and explanation of how
phase-conjugate mirrors work, deleted.]
> 		Small guide beam --> LEO powersat.
> 		LEO powersat --> LOTS OF ENERGY focused almost
> 			perfectly back down the "guide beam."
[                       . . .from an amplifying phase-conjugate mirror.]

	Problem is, a powersat in geostationary orbit will be so far away that
in the time it takes for your guide beam to get to the satellite, and the
power beam to get back, the atmospheric distortions recorded by your guide
beam will have changed enough to botch it up.  This is not a problem over
short distances -- turbulence can't do much in a few nanoseconds or
microseconds -- but the round-trip time (at lightspeed) to a satellite in
geostationary orbit is something like 0.3(?) second, enough time to mess things
up.

-- 
	-- Lucius Chiaraviglio
	   lucius@tardis.harvard.edu
	   {insert your favorite brave system here}!seismo!tardis!lucius

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