Re: shuttle disaster

[Pigeon <jah.pigeon@ukonline.co.uk>]

On Sat, Feb 08, 2003 at 01:42:50AM -0600, Nathan E Norman wrote:
> On Sat, Feb 08, 2003 at 01:41:01AM +0000, Pigeon wrote:
> > On Fri, Feb 07, 2003 at 02:37:53PM -0600, John Hasler wrote:
> > > Pigeon writes:
> > > > It would be under tension, because the upper station is outside the
> > > > geosynchronous orbit. So the bit above the break would fly off into
> > > > space, and the lower bit would fall back.
> > > 
> > > The tension would taper from nominally zero at the base to maximum at the
> > > attachment to the counterweight.
> > 
> > Unless I'm totally screwed up I don't think this is right...
> > everything below the geosynchronous orbit is orbiting too slowly to
> > stay up on its own, everything above the geosynchronous orbit is
> > orbiting too fast to not fly off unless anchored. So the maximum
> > tension is where the cable crosses the geosynchronous orbit; there are
> > minima at BOTH ends.
> > 
> > In theory, you wouldn't need a lumped counterweight - you could simply
> > extend the cable until the "loose end" had enough mass. This makes the
> > presence of a minimum at the outside end more obvious!
> 
> Isn't geostationary orbit ~22000 _miles_ above earth?  That'd be one
> hell of a cable.

Think it's more like 24,000... fortunately this particular
(lumped-counterweight-less) cable is one of those magic hypothetical
ones which abound in mechanics problems.

On Fri, Feb 07, 2003 at 10:03:50PM -0800, Paul Johnson wrote:
> s/geosynchronous/geostationary

I claim 1:41am exemption. :-)

Pigeon