Reconstructing Surface Heating from an Inflatable Atmospheric Re-entry Vehicle

The Low-Earth Orbit Flight Test of an Inflatable Decelerator (LOFTID) re-entry vehicle launched to low-Earth orbit aboard an Atlas V rocket in November 2022. The aeroshell, the largest Hypersonic Inflatable Aerodynamic Decelerator (HIAD) ever flown, was inflated to its full 6-meter diameter before successful re-entry into the atmosphere. LOFTID’s comprehensive instrumentation suite included 82 thermocouples (TCs) distributed across the aeroshell at various depths throughout the flexible thermal protection system (FTPS). This presentation will describe how the temperatures measured by the TCs during flight were used to estimate the surface heat rate across the aeroshell throughout the period of re-entry by inverse analysis methodology implemented in COMSOL Multiphysics®. The results were used to evaluate the fidelity of measurements from the total heat flux gauges on the nose, determine the surface heat flux across the entirety of the aeroshell, and compare to pre-flight CFD-based heating predictions, ultimately contributing to improved thermal models and design tools for NASA’s future HIAD missions.