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Re: Preferred Phase 3 Orbits





On Tue, 9 Jan 2001, John P. Toscano wrote:

> Why is a highly inclined orbit desirable for a Phase 3 satellite?
>
> Wouldn't a high, elliptical, 16-hour orbit at near zero inclination
> be quite satisfactory, especially if oriented so that the three
> apogee locations that recurred every 48 hours had views of:
>   1) Europe/Africa to Asia/Austrialia
>   2) Asia/Australia to North/South America
>   3) North/South America to Europe/Africa
>
> This would seem to have the advantage of not "favoring" either
> the northern or southern hemisphere.  (Or more to the point, not
> putting either hemisphere at a disadvantage.)
>
> I suppose it would mean that Alaska might never have a path to
> western Europe/Africa, and a QSO from the middle of the Pacific
> Ocean to the middle of the Atlantic Ocean would be unlikely, but
> those seem to be small prices to pay.
>

Unless you put the spacecraft in an orbit with a pretty high perigee, it
becomes inaccessible to each hemisphere as it nears perigee.  If the
subsatellite point is at 0 degrees lattitude and the spacecraft is at a
low perigee, it is below the horizon for pretty much everyone outside of
the equitorial belt.

If perigee occurs somewhere over the atlantic or pacific ocean, the
spacecraft becomes pretty much totally inaccessible for a period of time.

James - N5XNS

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