The EU-funded ICARUS project (HORIZON EUROPE, Grant No. 101134997) aims to advance key technologies for reusable space transportation systems, focusing on Inflatable Heat Shields (IHS) for launch vehicle stage recovery. The project targets TRL6 by maturing critical components such as the Flexible Thermal Protection System (FTPS), inflatable structures, and health monitoring sensors. Activities include mission/system design, flight testing of an IHS demonstrator on a sounding rocket, Plasma Wind Tunnel tests simulating orbital re-entry, and post-test analyses for model validation. This paper presents the development of the FTPS for the ICARUS Aerodemonstrator, covering requirement definition, material selection, sample testing, and breadboard evaluations. It also details the design and planning of representative SCIROCCO wind tunnel tests, the FTPS layout, current design status, numerical thermal modeling and results, and preliminary experimental findings. Future work to support FTPS qualification, manufacturing, and integration on the re-entry vehicle is also outlined.