1. Ra diation- S hapes- T hermal Protection Investig a tion s for High Sp eed Ea rth R e-entry J-M BOUILLY, A. PISSELOUP - EADS Astrium - Saint-Médard-en-Jalles, France O. CHAZOT - Von Karman Institute, Rhode-St-Genese, Belgium G. VEKINIS - Institute of Materials Science, NCSR "Demokritos", Greece A. BOURGOING - EADS Astrium Space Transportation, Les Mureaux, France B. CHANETZ - ONERA, Meudon, France O. SLADEK - Kybertec, s.r.o., Chrudim, Czec Rep. RASTAS SPEAR : Radiation-Shapes-Thermal Protection Investigations for High Speed Earth Re-entry The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement n° 241992 1 3rd International ARA Days - Arcachon, France 2011, May 2-4 - Session TPS-3

2. Ra diation- S hapes- T hermal Protection Investig a tion s for High Sp eed Ea rth R e-entry May 3rd 2011 - 3rd International ARA Days - Arcachon 2-4 May 2011 - Session TPS-3 2 Overview Introduction Objectives Overview of technical activities Review of System Requirements Ground Facilities Improvement Key Technologies for High Speed Entry Ablation – flight mechanics coupling assessment Gas-surface interactions modeling Next Steps / Conclusion

3. Ra diation- S hapes- T hermal Protection Investig a tion s for High Sp eed Ea rth R e-entry May 3rd 2011 - 3rd International ARA Days - Arcachon 2-4 May 2011 - Session TPS-3 3 In the frame of EC FP7 second call Activity 9.2 – strengthening of space foundations / research to support space science exploration SPA.2009.2.1.01 Space Exploration Duration Sep 2010 - Sep 2012 Status : Team composed of 10 partners Astrium is the coordinator Budget total : 2.3 M€ including 1.6 M€ EU grant More on www.rastas-spear.euwww.rastas-spear.eu 3 PartnerCountry ASTRIUM-ST SASFrance CIRA : Centro Italiano Ricerche Aerospaziali Italy CFS EngineeringSwitzerland NCSR DemokritosGreece CNRSFrance IoA : Institute of AviationPoland KYBERTECCzec Rep. MSU : Lomonosov Moscow State University Russia Office National d’Etudes et de Recherches Aérospatiales France VKI : Von Karman Institute for Fluid Dynamics Belgium Introduction

4. Ra diation- S hapes- T hermal Protection Investig a tion s for High Sp eed Ea rth R e-entry May 3rd 2011 - 3rd International ARA Days - Arcachon 2-4 May 2011 - Session TPS-3 4 10 partners from 8 European countries AST-F ONERA CNRS VKI CFS CIRA IoA MSU DEMOKRITOS KYBERTEC LANDING GEAR DEPARTMENT

5. Ra diation- S hapes- T hermal Protection Investig a tion s for High Sp eed Ea rth R e-entry May 3rd 2011 - 3rd International ARA Days - Arcachon 2-4 May 2011 - Session TPS-3 5 General Objective Sample Return Missions : an important step for Solar System Exploration After collecting samples, any return mission will end by high-speed re-entry in Earth’s atmosphere. This requires strong technological bases and a good understanding of the environment encountered during the Earth re-entry. Investment in high speed re-entry technology development is thus appropriate today to enable future planetary exploration missions in the coming decades. Mars Sample Return, Marco Polo...  Rastas Spear project to increase Europe’s knowledge in high speed re-entry vehicle technology Sample Return Capsule Other potential applications : ARV, Venus

6. Ra diation- S hapes- T hermal Protection Investig a tion s for High Sp eed Ea rth R e-entry May 3rd 2011 - 3rd International ARA Days - Arcachon 2-4 May 2011 - Session TPS-3 6 Objectives of the project OBJ1 (WP1, WP2, WP4 + WP5) To better understand phenomena during high speed re-entry enabling more precise Capsule sizing and reduced margins. OBJ2 (WP2) : To identify the ground facility needs for simulation OBJ3 (WP3) : To master heat shield manufacturing techniques and demonstrate heat shield capabilities. OBJ4 (WP3+WP4) : To master damping at ground impact and flight mechanics and thus ensure a safe return of the samples WORKPACKAGESWP Participants WP1 Review of System Requirements AST CNRS WP2 Ground Facilities Improvement AST CIRA CNRS VKI WP3 Key Technologies for High Speed Entry Mastering AST-F CIRA DEMOKRITOS IOA WP4 Ablation-Flight mechanics coupling assessment AST CIRA CNRS WP5 Gas-Surface interactions modelling AST CFS MSU ONERA WP6 Synthesis, Management & Coordination AST + KYBERTEC + WP leaders

7. Ra diation- S hapes- T hermal Protection Investig a tion s for High Sp eed Ea rth R e-entry May 3rd 2011 - 3rd International ARA Days - Arcachon 2-4 May 2011 - Session TPS-3 7 WBS WP1 Review of System Requirements 1.1 Atmosphere modelling 1.2 Trajectories 1.3 Aerodynamics & ATD 1.4 Vehicle Design WP3 Key Technologies for High Speed Entry 3.1: Choice of TPS + Joints 3.2: Flow tests 3.3: Breadboard manufacturing 3.4: Crushable Structure WP4 Ablation- Flight Mechanics Coupling assessment 4.1 Tools coupling 4.2 Ablation coupling assessment 4.3 Engineering modelling Correction by CFD WP5 Gas-Surface Interactions Modelling 5.1: Review of surface roughness and blowing influence 5.2: Ground Experiment Preparation 5.3: CFD Modelling 5.4: Synthesis of WP WP2 Ground Facilities Improvement 2.1: Analysis of Current Ground Facilities 2.2: Shock tube technology 2.3: Ballistic Range Technology 2.4: Plasma Generator Technology WP6 Management, Dissemination and Exploitation 6.1 Management 6.2 Dissemination & Exploitation 2.5: Synthesis

8. Ra diation- S hapes- T hermal Protection Investig a tion s for High Sp eed Ea rth R e-entry May 3rd 2011 - 3rd International ARA Days - Arcachon 2-4 May 2011 - Session TPS-3 8 WP 1 results: Review of System Requirements Main objective  provide with general inputs for any others WP  WP 1.1: Atmosphere modelling - Atmosphere compositions for Earth and Venus, - Thermochemical model (kinetic model + thermal model) available, with identification of all possible species and chemical reactions. EARTHVENUS complete model based on N2, O2 and Ar model based on CO2 and N2 mixture simplified model based only on N2 and O2

9. Ra diation- S hapes- T hermal Protection Investig a tion s for High Sp eed Ea rth R e-entry May 3rd 2011 - 3rd International ARA Days - Arcachon 2-4 May 2011 - Session TPS-3 9 May 3rd 2011 WP 1 results: Review of System Requirements  WP 1.2: Trajectories - Identification of generic aeroshapes with respect to candidate exploration missions. We focus our investigation on Earth entry, -Trajectories have been computed including usual design criteria -Flight domain determined with constraints on : -max heat flux, max heat load, max g-load Sphere cone 45° Diameter D =1100 mm Nose radius Rn = 275 mm

10. Ra diation- S hapes- T hermal Protection Investig a tion s for High Sp eed Ea rth R e-entry May 3rd 2011 - 3rd International ARA Days - Arcachon 2-4 May 2011 - Session TPS-3 10 WP 1 results: Review of System Requirements  WP 1.3: Aerodynamics & Aerothermodynamics - Aerodynamics: Newton Preliminary analysis - Aerothermodynamics (Aerothermal environment) Engineering methods for convective heating, Shock-layer radiation computations for radiative heating (CNRS activities)

11. Ra diation- S hapes- T hermal Protection Investig a tion s for High Sp eed Ea rth R e-entry May 3rd 2011 - 3rd International ARA Days - Arcachon 2-4 May 2011 - Session TPS-3 11 WP 1 results: Review of System Requirements  WP 1.4: Vehicle design IF Carrier Filling Foam FS Structure FS TPS Lid TPS Front Energy absorbing material Rear Energy absorbing material Lid structure Internal insulation Internal structure Sample Canister AFT TPS - Preliminary design of the generic capsule, and determination of TPS thickness, in order to define the Mass Centering and Inertia (MCI) assuming a given architecture - Preliminary requirements related to TPS for other WP : surface recession, mass loss, temperature evolution, gas flow rate,…

12. Ra diation- S hapes- T hermal Protection Investig a tion s for High Sp eed Ea rth R e-entry May 3rd 2011 - 3rd International ARA Days - Arcachon 2-4 May 2011 - Session TPS-3 12 WP2: Ground Facilities Improvement Objectives: Review High Enthalpy facilities and dedicated instrumentation Identification of ground testing facilities to reproduce flight environment Identification of testing facilities for TPS qualification First design of hypervelocity facility for Super-orbital reentry simulation Typical example: X2 facility in dual-driver expansion tunnel mode (UQ, Australia)

13. Ra diation- S hapes- T hermal Protection Investig a tion s for High Sp eed Ea rth R e-entry May 3rd 2011 - 3rd International ARA Days - Arcachon 2-4 May 2011 - Session TPS-3 13 Two kind of ground based facilities are involved to reproduce the typical flight environment: - Shock tube / Shock tunnels duplicate the shock layer and generate database for the radiation features - Plasma wind tunnels duplicate the boundary layer around the vehicle and allow TPS qualification  WP2 will review those facilities, provide recommendations for required performances of test facilities and associated methodologies, and preliminary define the hyper-velocity facility dedicated to high speed entry WP2: Ground testing strategy Bow shock Reacting BL Aerospace vehicle nose M>>1 Wall Chemistry Gas Surface Interaction Ablation Thermal Chemical NEQ Upstream flow Plasma wind TunnelShock Tube facility Shock wave Shock layer Real flight situation Radiation studiesTPS qualification TPS Boundary layer

14. Ra diation- S hapes- T hermal Protection Investig a tion s for High Sp eed Ea rth R e-entry May 3rd 2011 - 3rd International ARA Days - Arcachon 2-4 May 2011 - Session TPS-3 14 WP3: Key Technologies for High Speed Entry WP3.1. Iterative search for new joint and bonding adhesives Search for advanced adhesives for better performance Elementary characterisation Compare with heritage adhesives and optimise Develop new, efficient and lower cost manufacturing processes WP3.2. Arc Jet validation at CIRA/SCIROCCO Heat flux up to 15MW/m² (tbc) Testing of range of joints and geometries WP3.3. Manufacture a demo TPS shield to demonstrate the technologies developed in RASTAS SPEAR

15. Ra diation- S hapes- T hermal Protection Investig a tion s for High Sp eed Ea rth R e-entry May 3rd 2011 - 3rd International ARA Days - Arcachon 2-4 May 2011 - Session TPS-3 15 WP3: Key Technologies for High Speed Entry WP3.4. Crushable Structures Material selection for light damping structures Material characterisation tests Static Low speed dynamic Crush Modelling of energy absorption structures Manufacturing of corresponding item for techno demonstrator, and numerical validation

16. Ra diation- S hapes- T hermal Protection Investig a tion s for High Sp eed Ea rth R e-entry May 3rd 2011 - 3rd International ARA Days - Arcachon 2-4 May 2011 - Session TPS-3 16 WP4: Ablation – flight mechanics coupling assessment Objectives Based on WP1 results as inputs : flight environment, vehicle configuration 1- To assess impact of massive ablation on aerodynamic performances and stability along the entry trajectory path. 2- To identify recession level that could be tolerated with respect to capsule aerodynamic performances and stability requirements. 3- To elaborate and validate an engineering tool that couples: - Aeroshape aerodynamic, - Trajectory and stability, - Aerothermal environments, - TPS material thermal response - and then recession determination resulting in aeroshape modification. 4- To translate these results into criteria for maximum recession requirements in relation with usual landing accuracy, g-loads, heating and incidence profile issues.

17. Ra diation- S hapes- T hermal Protection Investig a tion s for High Sp eed Ea rth R e-entry May 3rd 2011 - 3rd International ARA Days - Arcachon 2-4 May 2011 - Session TPS-3 17 WP4: Ablation – flight mechanics coupling assessment Work logic: Synthesis WP4.1 – Tools Coupling (AST) Coupling of following tools: - Ablation & thermal TPS response code including Aeroshape modification - Shock shape & - Pressure distribution & - Aerodynamic coefficients determination by CFD code, including ablation gas products injection - 6 DoF Trajectory Tool WP4.2 – Tools Coupling Assessment (AST) WP4.3 – Engineering modelling Correction by CFD (AST – CIRA - CNRS) - Assessment of Ablations-flight mechanics effects for candidate Earth Entry capsule - Assessment of Aeroshape modification (CIRA) - Assessment of Radiation (CIRA-CNRS) - Assessment of Surface mass blowing (CIRA) - Identification of requirements for maximum TPS recession - Sensitivity to TPS ablative properties - Development of engineering tool to determine radiating heating vs. recession rate (AST) - Engineering correlation derivation from CFD computations (AST)

18. Ra diation- S hapes- T hermal Protection Investig a tion s for High Sp eed Ea rth R e-entry May 3rd 2011 - 3rd International ARA Days - Arcachon 2-4 May 2011 - Session TPS-3 18 Flow aerodynamics Trajectory Thermal response Ablation - Ablation & thermal TPS response code including Aeroshape modification - Shock shape & - Pressure distribution & - Aerodynamic coefficients determination by CFD code, incl. ablation products injection - 6 DoF Trajectory Tool WP 4.3 – Engineering modelling Correction by CFD (AST – CIRA - CNRS) Coupling of toolsDetailed inputs (radiation, blowing, shape change) Assessment of coupling effects Requirements for max TPS recession

19. Ra diation- S hapes- T hermal Protection Investig a tion s for High Sp eed Ea rth R e-entry May 3rd 2011 - 3rd International ARA Days - Arcachon 2-4 May 2011 - Session TPS-3 19 WP5: Gas-surface interactions modeling WP 5.1Review of surface roughness Critical analysis from real flight (Astrium/MSU) Bibliography about roughness and blowing (Onera/MSU) Turbulence model recommendations (MSU/Onera) WP 5.2 Ground experiment Tests in Mach 5 blow down wind tunnel (Onera) Test analyses (Euler + boundary layer) WP 5.3Model implementation Engineering model assessment (MSU/CFS) Next slides

20. Ra diation- S hapes- T hermal Protection Investig a tion s for High Sp eed Ea rth R e-entry May 3rd 2011 - 3rd International ARA Days - Arcachon 2-4 May 2011 - Session TPS-3 20 May 3rd 2011 WP5: Gas-surface interactions modeling Experiments in the blow down wind tunnel R2Ch Test Objective : qualification of the wall heat-flux with different roughness and blowing rate Wind tunnel characteristics : Mach 5 nozzle with an exit diameter : 326 mm p st : from 5 10 5 Pa to 50 10 5 Pa ; T st = 650 K Re (L=1 m) = 4.25 10 6 from 42.5 10 6 Model : Flat plate with a sharp leading edge, already available from a prior test campaign During tests : - Heat flux measurements by infrared thermography, - Schlieren photographs

21. Ra diation- S hapes- T hermal Protection Investig a tion s for High Sp eed Ea rth R e-entry May 3rd 2011 - 3rd International ARA Days - Arcachon 2-4 May 2011 - Session TPS-3 21 WP5: Gas-surface interactions modeling Three porous ceramic insert (porosity 48 %) - without roughness - with roughness r1 (pyramid height 100 microns) - with roughness r2 (pyramid height 300 microns) Characteristics of the roughness : pyramids joined and in staggered rows k b 2b l = 46,3mm L = 225,8mm

22. Ra diation- S hapes- T hermal Protection Investig a tion s for High Sp eed Ea rth R e-entry May 3rd 2011 - 3rd International ARA Days - Arcachon 2-4 May 2011 - Session TPS-3 22 WP5: Gas-surface interactions modeling Consequence for the tests : blowing with three mass-flow rates up to 3.8 kg/m²/s : - m1 : without blowing (reference case m1 = 0) - m2 : moderate blowing (m2 = 0.5 m3 = 1.9 kg/m²/s) - m3 : maximal blowing (m3 = 3.8 kg/m²/s) Z(km)m/(  V)  520.012 460.005 36.20.0012 mass-flow rate calculated on the maximum heat-flux trajectory (from Astrium MSRO study-2000)

23. Ra diation- S hapes- T hermal Protection Investig a tion s for High Sp eed Ea rth R e-entry May 3rd 2011 - 3rd International ARA Days - Arcachon 2-4 May 2011 - Session TPS-3 23 Next Steps WP 2 Review and description of dedicated shock tube and plasma facilities First design of hyper-velocity facility to simulate high speed Earth re-entry. WP 3Bibliographic review on joints materials Screening and testing of crushable materials Preparation of arc jet tests in Scirocco WP 4Flow computations with and without ablation products Preparation of tools for coupling WP 5Completion of bibliographic review Preparation and performance of ground experiments

24. Ra diation- S hapes- T hermal Protection Investig a tion s for High Sp eed Ea rth R e-entry May 3rd 2011 - 3rd International ARA Days - Arcachon 2-4 May 2011 - Session TPS-3 24 Conclusion Rastas Spear is a typical R&D project Part of European Community Framework Programme n°7 (FP7) Objective to increase the TRL of Key technologies Methodologies Project is now on-track Frame of the study has been defined Focus on passive Earth Return Capsule Remaining steps until end of study will allow completion of overall project objectives Completion Fall 2012

25. Ra diation- S hapes- T hermal Protection Investig a tion s for High Sp eed Ea rth R e-entry May 3rd 2011 - 3rd International ARA Days - Arcachon 2-4 May 2011 - Session TPS-3 25 Thank you for your attention More at www.rastas-spear.euwww.rastas-spear.eu 25