Flexible Ablative Thermal Protection Sizing on Inflatable Aerodynamic Decelerator for Human Mars Entry Descent and Landing

Abstract

Within its Entry, Descent and Landing Systems Analysis (EDL-SA) Project, NASA has been evaluating the technology investments required to enable human and large payload missions to Mars. In FY09 study was focused on Exploration-class cargo or crewed missions requiring 10 to 50 metric tons of landed payload. One of the deceleration concepts to achieve this goal employed a large Hypersonic Inflatable Aerodynamic Decelerator (HIAD). The HIAD would execute both aerocapture and atmospheric entry maneuvers at Mars and would therefore require a Thermal Protection System (TPS) capable of enduring dual heat pulse environments at high heat flux. This would most likely require an ablative TPS. At the time of the study, no flexible materials existed that met the estimated HIAD requirements. Based on current research, estimated flexible ablator material properties were created and used for a TPS sizing analysis of a dual heat pulse HIAD. These properties were used to perform HIAD TPS sizing analysis and additional trade studies. These studies demonstrate that the development of flexible ablators will lead to reasonable TPS masses for Hypersonic Inflatable Aerodynamic Decelerators.

Thermal Aeroelastic Characteristics of Inflatable Reentry Vehicle Experiment (IRVE) in Hypersonic Flow

“…Furthermore, these two problems were usually separated to, respectively, solve the surface temperature and structural dynamics under aerodynamic loads, and the one-way coupling method was most widely used. For example, McGuire et al established the three-dimensional heat conduction model of TPS and studied the temperature response after aeroheating solution [13]; Xu researched the dynamic response of IRVE and checked the structural stress after obtaining the steady aerodynamic force [14]. For the aeroheating problem, the one-way coupling of aeroheating and heat transfer is proved to be in good agreement with the high-enthalpy wind tunnel test [15].…”

Uncertainty Analysis of Radiative Heating for Multiple Planetary Entry Cases (Invited)

“…A proposed concept known as a Hypersonic Inflatable Aerodynamic Decelerator (HIAD) can be used to improve the down mass capability at other planets. 2,3,4,5,6 Suggested HIAD concepts consist of a geometry shape resembling a 70-deg sphere cone with diameters as large as 20 meters. A recent study by Johnston et al 7 has shown that the radiative heating on the aerothermal environment for missions to Mars is potentially significant, compared to convective heating due to resulting large diameters of a HIAD.…”