Hypersonic Entry Aeroshell Shape Optimization

Several different approaches to shape optimization are explored to identify hypersonic aeroshell shapes that will increase landed mass capability by maximizing drag-area for a specified lift-to-drag ratio. The most basic approach manipulates standard parameters associated with analytic aeroshell shapes like the sphere-cone and ellipsled. More general approaches manipulate the control points of a spline curve or surface. The parametric polynomial formulations of the Bezier and B-spline curves and surfaces are employed due to their desirable properties in shape design. Hypersonic aerodynamic analyses are carried out using Newtonian flow theory panel methods. An integrated optimization environment is created, and a variety of optimization methods are applied. In addition to a liftto-drag ratio constraint, size constraints are imposed on the aeroshell, as determined by payload volume requirements and launch vehicle shroud size restrictions. Static stability and center-of-gravity placement required to achieve hypersonic trim are also considered during optimization. An example case is presented based on the aeroshell for the Mars Science Laboratory mission.