I'm sure this is all very true. I'm not a sciencetician, and I don't even play one on TV, but there is something I do know. The earth isn't flat. We live on a sphere. Okay, it's not a perfect sphere, but it's the only one I got and I like it, but that isn't the point. Here's the point. Just because a sattelite is in orbit, doesn't mean it's looking straight down at something. Of course increasing the angle of viewing (or decreasing?) would only complicate the very good points already mentioned. There is also the problem of terrian elevation. As the sattelite comes closer to the horizon and is in a better position to view vertical objects the possibility of an obstruction increases dramatically. And.. as the satellite gets closer to the horizon problems occur with refraction. I think this scenario is simply very unlikely and extremely impractical, but still possible.

Damn! beat to the punch by the ever more descriptive and qualified to speak Custodian.