Aerodynamics of the RANGE Nanosatellites from Direct Flowfield Simulation Kenneth A. Hart, * Brian C. Gunter, † and Robert D. Braun ‡ Georgia Institute of Technology, Atlanta, GA, 30332-0150, USA One of the objectives of the RANGE mission is to perform relative navigation using differential aerodynamics. The aerodynamic force coefficients, moment coefficients, and heating can be computed numerically, though this process is too computationally expen- sive to integrate directly into an orbit propagator. A surrogate model is developed to improve the modeling fidelity beyond a simple sphere or plate model without significantly increasing computational cost. The training points for this model come from an industry standard code for Direct Simulation Monte Carlo analysis. Detailed discussions of model development, validation, and results are included. Nomenclature C Coefficient, see subscripts CFD Computational fluid dynamics DAC DSMC Analysis Code DSMC Direct Simulation Monte Carlo H Heaviside function LEO Low-Earth orbit MFE Model fit error ˆ n Surface normal, oriented outward ˙ Q Total convective heat rate r 0 RBF tuning parameter RANGE Ranging and Nanosatellite Guidance Experiment RBF Radial basis function ˆ t Surface tangent vector ˆ V ∞ Freestream velocity direction Subscripts A Axial D Drag L Lift N Normal p Pressure S Side T Tangential τ Shear Symbols α Angle of attack β Sideslip angle θ Angle of incidence σ Accommodation coefficient, see subscripts * Graduate Research Assistant, Daniel Guggenheim School of Aerospace Engineering, AIAA Student Member. † Assistant Professor, Daniel Guggenheim School of Aerospace Engineering, AIAA Senior Member. ‡ David & Andrew Lewis Professor of Space Technology, Daniel Guggenheim School of Aerospace Engineering, AIAA Fellow. 1 of 15 American Institute of Aeronautics and Astronautics Downloaded by GEORGIA INST OF TECHNOLOGY on October 7, 2016 | http://arc.aiaa.org | DOI: 10.2514/6.2016-5520 AIAA SPACE 2016 13 - 16 September 2016, Long Beach, California AIAA 2016-5520 Copyright © 2016 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved. SPACE Conferences and Exposition