At the moment I'm working on a simple simulation of an Earth-orbiting spacecraft. This involves centring the camera on my spacecraft which is orbiting a few hundred kilometres above Earth and simultaneously rendering the planet itself out to a distance of around 12000km. Of course, it's unfeasible to render such a scene using metres as my base unit, as I have to specify the spacecraft's position in hundreds of thousands of metres relative to the centre of Earth, and using such massive numbers to position objects in Direct3D seems to cause problems.
So, my question is: how would you approach the problem of rendering small scenes embedded in much larger ones? Should I render the Earth first followed by the spacecraft using different units each time? If you know of any useful articles or tutorials, that would be great