In this thread, Erroneous posted this really cool link about satellites. And in this other thread pldennison mentioned a photograph showing six satellites, four of which were going east to west.
So my questions are: Do most satellites orbit east to west? What are the advantages of orbiting east to west or vice versa, and how about north to south or south to north?
Most rockets use the rotation of the earth to assist in acheiving orbital velocity. The extra “boost” results in a savings in fuel. So, I guess you could say it’s just more economical.
Most satellites as we know them(communication) are in what is known as geostationary orbit. They turn as does the earth.Thats the only way that a dish could receive without constantly moving the dish.
The Russians came up with a system of South to north moving satellites that orbited so as one moved out of position another came up the horizon so the dish actually had to track.
justwannano is right if you include the word “important”. I think that with current UN regulations, the total number of geosychronous satellites is somewhere in the neighborhood of 80 or less, because geosyncsats must be at least 900 miles apart from each other. 22,300 miles x 3.14 / 900 = about 78.
However, there are many, many more satellites in LEO (low Earth orbit) than there are in geosynchronous orbit. In the late 80’s, NORAD was tracking some 4000 orbiting “satellites” ranging from camper-sized space stations to debris the size of a hex-nut. Now, that number is undoubtedly much greater.
West-to-east is the way to go with a rocket launch because you can pick up as much as 1100 mph simply by launching in that direction at the equator. Depending on the type of propellant you are using and the payload you are deploying, that can spell the difference between launch and redesign. When it costs something like $1,000-10,000 to launch two and a half pounds into orbit (on the Space Shuttle), free energy is a definite plus.
I can’t find a schematic of it right now, but you might find it worthwhile to get a look at Globalstar’s constellation.
48 satellites, in inclined rocker orbits (I think that was the name for that kind of orbit), low to the earth.
It looks like one of those atom models from high school. Those satellites are all over the place. Way cool.
OK, now I found one. Check this out: http://www.ee.surrey.ac.uk/Personal/L.Wood/constellations/globalstar3d.html