Why do orbits curve?
I am trying to figure out why the orbits of the Space Station and the Shuttle Orbiter are curved – from South to North then North to South in nature. There are satellites that circumnavigate the earth in parallel orbits – why not these two? I realize that the earth tilts on its axis, which creates a wobble, but the orbits of these 2 man made space objects against a map of the earth should be a straight line from West to East. Since it is not, I just have to know … why? Reply I think your problem is concerned not with the shape of the orbit but with the way it appears on a flat map. Suppose the Earth was a perfect sphere, and a spacecraft kept a fixed altitude of, say, 300 miles. Then its orbit would always be a circle around the center of the Earth, and the plane of that orbit (like any flat plane that includes the center of the Earth) would cut the sphere of the Earth into two equal halves. Two such planes, representing the orbital planes of two different satellites, will therefore
