Comparison of Statistical Estimation Techniques for Mars Entry, Descent, and Landing Reconstruction

Flight data from an entry, descent, and landing sequence can be used to reconstruct the vehicle's trajectory, aerodynamic coefficients, and the atmospheric profile experienced by the vehicle. Past Mars missions have not contained instrumentation that would allow for the separation of uncertainties in the atmosphere and the aerodynamic database. The 2012 Mars Science Laboratory took measurements of the pressure distribution on the aeroshell forebody during entry and allows freestream atmospheric conditions to be partially observable. Methods to estimate the flight performance statistically using onboard measurements are demonstrated here through the use of simulated Mars data. A range of statistical estimators, specifically the extended Kalman filter and unscented Kalman filter, are used to demonstrate which estimator best quantifies the states and the uncertainties in the flight parameters. The techniques demonstrated herein are planned for application to the Mars Science Laboratory flight dataset.