Development of Inflatable Heat Shield Technology for Re-Entry Systems in EFESTO project

The EFESTO project is funded by the European Union H2020 program. The purpose is to increase European capabilities in designing Inflatable Heat Shields for re-entry vehicles. The technology of inflatable heat shields enables increasing the spectrum of space-based applications as it provides effective heat protection and deceleration capabilities for atmospheric descent while being comparatively mass and volume efficient which is a significant asset for a space mission. The use of inflatable heat shields for Mars exploration and for Earth re-entry of a launcher upper-stage for later reuse were selected at the initial study phase as potential application for the HIAD technology. These two application cases are to demonstrate the performance of this technology under realistic conditions and to provide a representative study frame for the design of inflatable heat shields trained at tangible applications. In the first part of the project, the work focused on the system design of both study cases. This work yielded an inflatable heat shield design that shows a reduced complexity in geometry compared to the initial design and is scalable for other applications. Several stacks of material layers for the Flexible Thermal Protection System (F-TPS) were traded against each other before selecting one reference definition for the consecutive project phases. An intense test activity followed this phase. Part of the tests served for verifying the thermal performances of the F-TPS under relevant aerothermal environment using the plasma wind tunnel test infrastructure available within the consortium. In addition, a high-fidelity inflatable structure ground demonstrator was manufactured. This demonstrator served to consolidate the mechanical characterization of the inflatable system. This testing activity provided the data used for numerical cross-correlation and experimental-numerical rebuilding. Eventually, computational folding analysis completed the numerical activity during this project phase. The final project phase is dedicated to the preliminary design of an in-orbit demonstration mission for the technology and design of the technology development roadmap. This potential future In-Orbit Demonstrator (IOD) shall provide knowledge of the system performance while evolving in a relevant environment. This will provide in-flight verification and validation of the developed inflatable heat shield technology. This paper gives an overview of the project with a focus on system aspects of the EFESTO project about to be completed in the coming weeks.