The general relativistic equations of motion and range measurement relations for an earth-orbiting satellite such as LAGEOS were investigated in the barycenter coordinate system. In comparison with the Newtonian equations, modifications must be made to the satellite acceleration, the light time measurement, station clock times, and station position coordinates. Modifications to the measurement computation are also necessary in order to continue to operate formally in an earth-centered coordinate system. Limited comparisons of data reduction results using Newtonian equations with results using the Einsteinian formulation show that estimated baselines between LAGEOS tracking stations are affected at the several centimeter level. In three of four cases, rms of fit was sligthly improved using the relativistic formulation.