[orionblamblam]

> 'Surface-to-space' intercepts *are* calculated assuming a stationary earth.

Please, tell me more...

[GourmetDan]

Orbital Dynamics for the Compleat Idiot

"The coordinate system used in this tutorial has its origin at the center of Earth. In this coordinate system the Sun goes around the earth, contrary to what you may have heard. There is actually no harm in this viewpoint, since the origin of coordinates can always be whatever is convenient. It is true that Earth would be an awkward origin if we were interested in the motion of other planets (since they have complicated orbits in Earth-centered coordinates), but the planets do not sensibly affect Earth satellites, the subject of interest here, so the center at Earth will do fine."

http://www.nwc.navy.mil/press/Review/1999/winter/s&d1-w99.htm