Prediction and validation of Mars Pathfinder hypersonic aerodynamic database

Postflight analysis of the Mars Pathfinder hypersonic, continuum aerodynami c database is presented. Measured data include accelerations along the body axis and axis normal directions. Comparisons of preflight simulation and m easurements show good agreement. The prediction of two static instabilities associated with movement of the sonic line from the shoulder to the nose a nd back was confirmed by measured normal accelerations. Reconstruction of a tmospheric density during entry has an uncertainty directly proportional to the uncertainty in the predicted axial coefficient. The sensitivity of the moment coefficient to freestream density, kinetic models, and center-of-gr avity location are? examined to provide additional consistency checks of th e simulation with flight data. The atmospheric density as derived from axia l coefficient and measured axial accelerations falls within the range requi red for sonic line shift and static stability transition as independently d etermined from normal accelerations.