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Path: utzoo!utcsri!ubc-vision!alberta!cadomin!andrew
From: andrew@cadomin.UUCP (Andrew Folkins)
Newsgroups: net.space
Subject: Re: Another Use for Tethers
Message-ID: <651@cadomin.UUCP>
Date: Mon, 13-Jan-86 14:00:40 EST
Article-I.D.: cadomin.651
Posted: Mon Jan 13 14:00:40 1986
Date-Received: Mon, 13-Jan-86 17:45:59 EST
References: <8601101806.AA00639@s1-b.arpa>
Reply-To: andrew@cadomin.UUCP (Andrew Folkins)
Organization: U. of Alberta, Edmonton, AB
Lines: 25
Summary: 

In article <8601101806.AA00639@s1-b.arpa> dietz@SLB-DOLL.CSNET (Paul Dietz) writes:
>Even if they aren't used for launching things, tethers may be very
>useful for generating angular momentum in spinning space structures.
>For example, a space station could be spun up by extending two very
>long cables with small reaction engines on the ends.  The cables would
>be spun up and, because of the long moment arms, would acquire large
>amounts of angular momentum.  An electric motor anchored to the cables
>at the hub could then spin up the station, gradually slowing the cables.
>When the cables are stationary they would be retracted.  This is much
>more mass efficient than using reaction engines on the space station itself.

Umm, what stops the cables from just wrapping around the station?  This
scheme would work, but you would need rigid 'towers' instead of cables, and
the mass needed for these towers might be large enough to offset any fuel
savings.  One last point, the cables will only be stationary with respect
to the station, and they will still have a considerable amount of angular
momentum. Retracting them would spin up the station even more, just like
a spinning figure skater.  


-- 
Andrew Folkins        ...ihnp4!alberta!andrew    
 
All ideas in this message are fictional.  Any resemblance, to any idea,
living or dead, is purely coincidental.