James Ellis <ejge@...> wrote:

> Hi all
>
> I've just read that the Russians plan to deorbit Mir somewhere east of
> Australia, hopefully not NZ! in Feb 2001.
>
>
> Is the orbit to unstable to make any accurate simulations with Guide?

Most likely it is. To predict the final revolutions of a decaying
satellite with any reasonable accuracy is a tricky matter. Apart from
earth gravity data you also need air density data, and it's not sufficient
to base that data on some standard atmosphere but you need to base it
on actual air densoty measurements as much as you can.

Yes, Guide has tons of features, but I don't think it (yet?) has any
feature to input air density data to improve the accuracy when predicting
when and where a satellite will decay into the lower atmosphere.

> I'm not a real satellite buff but as this one is the equivalent of a large
> rusty Volvo

You mean it's not equivalent to a non-rusty Volvo or a rusty non-Volvo? <g>

> I am interested to see if it will appear over Sydney.
>
> Remember Skylab hit WA in (75?)
>
> Cheers
>
> hoping I haven't hurt any Volvo drivers

Don't worry -- you could really substitute with any car brand name
here -- and whether it's rusty or not matters little to its mass.
Also, Volvo didn't just manufacture regular cars but also trucks, and
I think Mir is more the size of a truck than of a regular car. Don't
you agree?

Finally, Volvo is nowadays an american company -- it was bought some
years ago by Ford. So today the only remaining Swedish manufacturers
of trucks is Scania....

----------------------------------------------------------------
Paul Schlyter, Swedish Amateur Astronomer's Society (SAAF)
Grev Turegatan 40, S-114 38 Stockholm, SWEDEN
e-mail: pausch at saaf dot se or paul.schlyter at ausys dot se
WWW: http://hotel04.ausys.se/pausch http://welcome.to/pausch