Path: utzoo!attcan!uunet!husc6!bbn!oberon!cit-vax!tybalt.caltech.edu!palmer
From: palmer@tybalt.caltech.edu (David Palmer)
Newsgroups: sci.space
Subject: Re: Cometesimals
Summary: A hammer in the mist
Message-ID: <6951@cit-vax.Caltech.Edu>
Date: 15 Jun 88 00:23:33 GMT
References: <880608203735.21400546@Iowa> <18206@cornell.UUCP> <18262@cornell.UUCP>
Sender: news@cit-vax.Caltech.Edu
Reply-To: palmer@tybalt.caltech.edu.UUCP (David Palmer)
Organization: California Institute of Technology
Lines: 26

In article <18262@cornell.UUCP> dietz@loki (Paul F. Dietz) writes:
>In article <18206@cornell.UUCP> dietz@loki (Paul F. Dietz) writes:
>
>> Frank et. al. estimate a density of about 3e-12 cometesimals per
>> cubic kilometer.  Travelling at 20 km/sec, the flux of comets
>> near the earth would be something like 6e-11 per square kilometer
>> per second.  A ten square kilometer powersat would be hit once
>> every fifty years, on average.
>
>Correction:  3e-11 per km^3, and 10 km/sec, not 20.  So the powersat
>is hit once every ten years, on average, if the cometesimals exist.
>
>	Paul F. Dietz
>	dietz@gvax.cs.cornell.edu

Comet strikes need not be fatal if the powersat is designed reasonably.
A 10 meter snowball would merely make a 10 meter hole in whatever it hit,
plus whatever damage the fragments do, if the structure is sufficiently
flimsy.  There is no reason to make the structure rigid enough that the
comet delivers the bulk of its energy to the rest of the structure.
		David Palmer
		palmer@tybalt.caltech.edu
		...rutgers!cit-vax!tybalt.caltech.edu!palmer
	"In retrospect, no one should have been surprised by the discovery
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