Asymmetrically Stacked Tori Hypersonic Inflatable Aerodynamic Decelerator Design Study for Mars Entry

Abstract

The Mars missions envisioned in the future require payload mass in excess of the current capable limit for entry vehicle technology. Deployable Hypersonic Inflatable Aerodynamic Decelerators offer one solution to successfully carry out the beginning of an entry architecture as payload mass increases. The majority of the research that has been conducted on these structures only focuses on axisymmetric geometries. In this investigation, aerodynamic performance and stability is examined for three proposed asymmetric families that can generate non-zero lift-to-drag ratios at 0° angle of attack. Advantages of an asymmetric lifting Hypersonic Inflatable Aerodynamic Decelerator include a larger entry corridor, reduced peak heating, larger range, and improved landing accuracy. In particular, there is potential to increase drag performance and reduce ballistic coefficient to mitigate entry, descent, and landing concerns. Blunt, asymmetric Hypersonic Inflatable Aerodynamic Decelerator designs considered are assembled from stacked tori configurations with a base diameter of 20 m and the capability to interface with a 10 m diameter rigid center body. The configurations considered are capable of producing hypersonic lift-to-drag ratios between ~0.6 and ~0.1 for angles of attack ranging from -30° to 20°. A 40 (t) entry mass, approximate mass of large robotic or human scale mission, is assumed resulting in ballistic coefficients from ~78 kg/m 2 to ~113 kg/m 2 . From the analyses conducted thus far, encouraging results project asymmetric Hypersonic Inflatable Aerodynamic Decelerators as conceivable candidates for future large scale Mars missions.