Xref: utzoo sci.space:8257 sci.space.shuttle:1975
Newsgroups: sci.space,sci.space.shuttle
Path: utzoo!henry
From: henry@utzoo.uucp (Henry Spencer)
Subject: Re: Stopping Space and Light Pollution.
Message-ID: <1988Nov17.173505.7601@utzoo.uucp>
Organization: U of Toronto Zoology
References: <1988Nov11.213348.27877@utzoo.uucp> <1084@esunix.UUCP>
Date: Thu, 17 Nov 88 17:35:05 GMT

In article <1084@esunix.UUCP> bpendlet@esunix.UUCP (Bob Pendleton) writes:
>> Breaking the existing
>> debris up into smaller bits is the *last* thing we want to do.
>
>Not really. Even a fairly heavy rain of microscopic particles can be
>stopped more easily than one large chunk.

*Microscopic* particles aren't that much of a problem.  Macroscopic ones
are.  A fairly light rain of coin-sized particles is a WHOLE LOT harder
to deal with than one large chunk, which can at least be tracked and avoided.

If we can't utterly pulverize the debris, we don't want to break it up
at all.  Unfortunately, hypervelocity collisions are non-intuitive in some
ways.  Based on the SDI Delta experiment, if two fairly large chunks hit
each other, the shock wave from the instant of first contact explodes
both, and the debris clouds then pass through each other without interacting
much.  There is more than enough energy there to vaporize everything, but
it doesn't get applied efficiently.  Any plan to get rid of debris with
collisions will have to be studied and tested *very* carefully to make
sure that it isn't going to make things worse.
-- 
Sendmail is a bug,             |     Henry Spencer at U of Toronto Zoology
not a feature.                 | uunet!attcan!utzoo!henry henry@zoo.toronto.edu