Hi all, What, if any, is the name given to the type of orbit that the three "Sirius" broadcast satellites use? It shows as a figure-eight and altitude is between 24000KM, and 47000KM.
Auke de Jong VE6PWN DO33go Edmonton, AB
Dear,
A record of this contact is available to the folowing link : http://www.amsat-france.org/ariss/article.php3?id_article=265.
The web page and the contact are in french
73's
Christophe
The Sirius birds are in an "Inclined Orbit". It's explained more in the WikiPedia entry, about half way down the page. http://en.wikipedia.org/wiki/Sirius_radio
73, Jim KQ6EA
--- "Auke de Jong, VE6PWN" sparkycivic@shaw.ca wrote:
Hi all, What, if any, is the name given to the type of orbit that the three "Sirius" broadcast satellites use? It shows as a figure-eight and altitude is between 24000KM, and 47000KM.
Auke de Jong VE6PWN DO33go Edmonton, AB
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On 21 Feb 2008 at 10:29, Jim Jerzycke wrote:
The Sirius birds are in an "Inclined Orbit". It's explained more in the WikiPedia entry, about half way down the page. http://en.wikipedia.org/wiki/Sirius_radio
73, Jim KQ6EA
--- "Auke de Jong, VE6PWN" sparkycivic@shaw.ca wrote:
Hi all, What, if any, is the name given to the type of orbit that the three "Sirius" broadcast satellites use? It shows as a figure-eight and altitude is between 24000KM, and 47000KM.
Auke de Jong VE6PWN DO33go Edmonton, AB
Is this type of orbit can be a solution for the next HEO?
Tundra orbit is a type of highly elliptical orbit with a high inclination (usually near 63.4°) and an orbital period of one sidereal day (almost 24 hours). A satellite placed in this orbit spends most of its time over a chosen area of the Earth, a phenomenon known as apogee dwell.
These are conceptually similar to Molniya orbits which have the same inclination but half the period (about 12 hours). The only user of Tundra orbits is Sirius Satellite Radio, which operates a constellation of three satellites.
References:http://en.wikipedia.org/wiki/Tundra_orbit
"-"
Luc Leblanc VE2DWE Skype VE2DWE www.qsl.net/ve2dwe WAC BASIC CW PHONE SATELLITE
On Feb 21, 2008, at 10:29 AM, Jim Jerzycke wrote:
The Sirius birds are in an "Inclined Orbit". It's explained more in the WikiPedia entry, about half way down the page. http://en.wikipedia.org/wiki/Sirius_radio
What I read says it's in a "geosynchronous highly elliptical" orbit. Strictly speaking, you can't have a truly geosynchronous orbit that's elliptical (it must be circular). It must also have an inclination of zero.
But: the inclined elliptical orbit causes the satellite to speed up relative to Earth's rotation during parts of its orbit, and slow down during others. This is what causes the East-West motion of the figure- eight. The inclination is what gives the North-South motion. The two are combined in such a way as to give a nice figure-eight pattern over the surface of the Earth.
The Wikipedia entry refers to this as a "Tundra Orbit":
http://en.wikipedia.org/wiki/Tundra_orbit
participants (5)
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Auke de Jong, VE6PWN -
AVMDTI -
Jim Jerzycke -
Luc Leblanc -
Rick Mann