[meteorite-list] space engines

From: Francis Graham <francisgraham_at_meteoritecentral.com>
Date: Thu Apr 22 10:04:54 2004
Message-ID: <20020529144928.49061.qmail_at_web12905.mail.yahoo.com>

Hello List,
--- David Calongne <calongnedav_at_webtv.net> wrote:
> hi list, interesting article
> www.msnbc.com/news/755843.asp
> see ya david
>

  I see even the space elevator was contemplated in
the article. At the 111th meeting of the Ohio Academy
of Sciences, I presented "A Pluto Charon Cable
Spacecraft" which takes advantage of the fact that
Pluto and Charon are mutually tidally locked and the
orbit is circular to likely within 25 km. A steel
cable (no exotic materials required) could be strung
between them and a cable spacecraft go up and down
between them with more efficiency (using
electromagnetic braking) than reaction propulsion
alone. I specified the size and design of a possible
cable-car spacecraft. The abstract is in the latest
Ohio Journal of Science. For the small noncircularity
of the orbit, the cable could be spooled a bit or
retracted underground.
   I found out after the paper that Charles Sheffield
had the germ of this idea in a footnote in a table in
the appendix to his excellent Web Between the Worlds,
and also in an earlier publication where this table
appeared. But I and my calculus tutee Bob Dinkel first
realized that steel will work, no exotic diamond
fibers needed, because Pluto and Charon are so small.
   Of course, the question at the meeting was "Why
would anyone build such a thing between Pluto and
Charon?" Tsk tsk. Such questions are sooooo 20th
century.

Francis Graham

PS Similarly, cables could be strung between double
asteroids. Besides cable transport, what other uses
would they have? I wonder.


__________________________________________________
Do You Yahoo!?
Yahoo! - Official partner of 2002 FIFA World Cup
http://fifaworldcup.yahoo.com
Received on Wed 29 May 2002 10:49:28 AM PDT