Development of an Aerothermal Model for an Inflatable Aerodynamic Decelerator

Cristele Sofia Malacute dos Santos

Key information

Authors:

Cristele Sofia Malacute dos Santos (Cristele Sofia Malacute dos Santos)

Supervisors:

Frederico José Prata Rente Reis Afonso (Frederico Afonso); Fernando José Parracho Lau (Fernando José Parracho Lau)

Published in

July 8, 2025

Abstract

Vehicle recovery from orbital missions requires scalable and thermally resilient solutions that enable reusability without compromising performance. This dissertation investigates the feasibility of using a deployable Inflatable Aerodynamic Decelerator (IAD) to enable atmospheric reentry and recovery of orbital components. A simulation framework is developed, coupling a trajectory propagation code with a transient thermal analysis for a multi-layer Flexible Thermal Protection System (FTPS). The model is validated by reproducing the LOFTID (Low-Earth Orbit Flight Test of an Inflatable Decelerator) flight test, conducted by NASA. The thermal response model is critically assessed under the same mission conditions, as detailed in-depth temperature data are not publicly available for validation. Transient conduction through the FTPS is resolved using a one-dimensional finite-difference method, with convergence verified and material limits evaluated. A parametric study is conducted to assess the sensitivity of aerothermal loads to variations in geometry and entry conditions. Results show that increasing the diameter, nose radius, and cone angle consistently reduces stagnation heat fluxes and dynamic pressures, thus improving thermal protection and minimizing aerothermal loads, while ensuring sufficient aerobraking, supporting optimization studies adapted to different mission objectives. For the LOFTID reference configuration, the recoverable vehicle mass increased from 1100 kg to 2336 kg, without exceeding material limits. Other optimized configurations enabled recovery of masses above 10 000 kg or diameters up to 14.29 m. The developed framework supports the exploration of design alternatives and trade-off analysis between thermal protection sizing, aerodynamic performance and recoverable mass, contributing to a better understanding of reusable reentry systems.