Aerodynamic drag and lift effects on the inclination of the orbit of the S3-a satellite (1974-85D) have been used to infer atmospheric zonal wind speeds at an altitude of 175 km and to estimate the satellite surface thermal accomodation coefficient. The unusually high quality of the orbital and attitude data permitted the 7-month data span to be analyzed in six nonoverlapping subintervals, thereby resulting in finer local time and spatial resolution than is normally obtained in such studies. The aerodynamic lift force was found to be quite sensitive to the assumed value of the thermal accomodation coefficient, a quantity that is neither well known nor well understood. The inclination data were best fit (in a least squares sense) when the accommodation coefficient was greater than 0.95. Best agreement with theoretical models in terms of wind speed and direction was obtained when the accommodation coefficient was taken to be nearly 1.0. In this case the inferred wind was ~400 m/s eastward at 1900-2100 LT and ~200 m/s westward at 0700-0900 LT. The study indicates that if accurate zonal wind velocities are to be derived from satellite orbital inclination changes, care must be taken to ensure that the shape and orientation of the satellite are such that the lift forces generated are sufficiently small that the resulting uncertainty due to inadequate knowledge of the accommodation coefficient does not cause significant error.