Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!mnetor!seismo!lll-crg!styx!mordor!sri-spam!sri-unix!hplabs!decwrl!decvax!tektronix!uw-beaver!ubc-vision!alberta!andrew
From: andrew@alberta.UUCP
Newsgroups: sci.space
Subject: Re: Powersats
Message-ID: <707@cadomin.alberta.UUCP>
Date: Tue, 11-Nov-86 16:42:43 EST
Article-I.D.: cadomin.707
Posted: Tue Nov 11 16:42:43 1986
Date-Received: Sun, 16-Nov-86 20:11:22 EST
References: <8611032037.AA00701@s1-b.arpa> <7278@utzoo.UUCP> <1310@ttrdc.UUCP>
Reply-To: andrew@cadomin.UUCP (Andrew Folkins)
Organization: U. of Alberta, Edmonton, AB
Lines: 25

In article <1310@ttrdc.UUCP> levy@ttrdc.UUCP (Daniel R. Levy) writes:
>In article <7278@utzoo.UUCP>, henry@utzoo.UUCP (Henry Spencer) writes:
>>(The reasons to use microwaves from powersats rather than just settling
>>for normal sunlight are (a) much higher conversion efficiencies, and
>>(b) the powersat beam is there day and night and largely ignores clouds.)
>
>There day and NIGHT?  Where does it get its night power (I am presuming
>a solar power source)?  It would have to be in a pretty durn high orbit
>( :-), and synchronous orbits are kinda low, aren't they? ) for the earth
>not to block the sun from the powersat at night!

22,300 miles is not *that* low.  The important fact is that the plane of
the powersat's orbit (equatorial) is inclined to that of the Earth's
orbit by 23.5 degrees.  The powersat only passes through the Earth's 
shadow when the line of intersection of the two planes is collinear with 
the Earth and the Sun, which only happens twice a year.  The net result 
is that objects in Clarke orbits are only in darkness for about 90 minutes 
each year.

--
Andrew Folkins    ...ihnp4!alberta!andrew    
The University of Alberta, Edmonton, Alberta, Canada      

Arthur C. Clarke's Law : 
   It has yet to be proven that intelligence has any survival value.