Configuration options for hypersonic flaps for mars entry systems

Previous Mars entry, descent, and landing systems have utilized bank-angle maneuvers to steer during the hypersonic phase of entry. An alternate solution for hypersonic steering is a set of independently-articulated aerodynamic flaps. Deflecting these flaps results in trim at non-zero angles of attack and sideslip angles, enabling the vehicle to generate lift in arbitrary directions. This study investigates configuration options for flap-based steering systems for Mars entry applications. Configurations are parametrically studied by varying the number, size, geometry, and locations of flaps. Results from a computational aerodynamic trim solver indicate that the aerodynamic control authority of an entry vehicle can be increased by using a high number of flaps, and by using flaps with large areas and moment arms. Flap-steering vehicles also exhibit range capabilities with markedly different shapes than bank-angle steering vehicles with equivalent maximum lift-to-drag ratios. Results also show that as the number of flaps increases, a flap-steering vehicle behaves increasingly similar to a bank-angle steering vehicle with the same maximum lift-to-drag ratio.