Recently, logn-term orbital data form the artificial satellite Lageos Have been analyzed to determine the rate of post-glacial rebound. Rubincam has compared the observed values against values derived from the realistic earth models (Wu-Peltier L1,L2), working with the second harmonic mode of excitation. The data support model L1, wih a uniform mantle viscosity of 1022 poise, over 1.2, with a lower mantle viscosity of 1023 poise. We find the higher degree harmonic contributions are significant, and considerably strengthen the support for model L1. We perform such calculations using the same parameter values for glaciation as Rubincam, and also values due to Peltier and coworkers. We also show that a similar analysis of data from the satellite Starlette is less likely to be as definitive as analysis of Lageos data, since there are significant contributions from very high harmonics, indicating that the behavior of the earth must be known in much greater detail.