FP7/SPACE PROJECT “HYDRA” Hybrid Ablative Development For Re-Entry In Planetary Atmospheric Thermal Protection

J. Barcena1, S. Florez1, B. Perez1, J-M. Bouilly2, G. Pinaud2, W. P. P. Fischer3, A. de Montbrun4, M. Descomps4, D. Lorrain4, C. Zuber5, W. Rotaermel5 and H. Hald5, P.

Portela6, K. Mergia7, G. Vekinis7, A. Stefan8, C. Ban8, D. Bernard9, V. Leroy9, R. Wernitz10, A. Preci10 and G. Herdrich10

1Tecnalia Research & Innovation, 2Astrium SAS (France), 3Astrium GmbH(Germany), 4 Lièges HPK SA (France), 5DLR (Germany), 6High Performance Structures – HPS (Portugal), 7N.C.S.R "Demokritos"

(Greece), 8INCAS (Romania), 9ICMCB-CNRS (France), 10IRS – University of Stuttgart (Germany

The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement n° 283797

08-04-2013 / 2OUTLINE

INTRODUCTION AND MOTIVATION

CONCEPT OF THE PROJECT

CONSORTIUM, SCHEDULE AND WPs LOGIC

MISSION REVIEW AND TPS SPECIFICATIONS

MATERIALS STATE OF THE ART AND TRADE-OFF

MATERIALS SELECTION AND PROCUREMENT

BONDING & TPS ASSEMBLY

SIMULATION AND TPS DESIGN

CHARACTERISATION & VERIFICATION PLAN

SUMARY AND MAIN CONCLUSIONS

ACKNOWNLEDMENTS

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Original approaches based on ablative materials and novel TPS solutions are required for space applications where resistance in extreme oxidative environments and high temperatures are required. The atmospheric entry of space vehicles from high-energy trajectories requires high-performance thermal protection systems that can withstand extreme heat loads.

A new scenario has appeared due to a worldwide change in space mission planning strategies with entry vehicles going back to capsule designs and ablators are re-gaining attention.

Consequently, the development of new, more efficient materials and systems is a must. Such developments, nevertheless, have to be subject to extensive experimental investigations using suitable facilities. In this view, the investigation and development of new materials based on ablative and thermostructural concepts is crucial. A new (hybrid) concept based on the combination of both type of TPS materials is proposed.

The advantage of the ceramic for this function is the low density compared to ablative material and the excellent thermal performance in this heat load range, as well as the stability of the shape of TPS which is an advantage for the aerodynamic of the re-entry vehicle.

Another asset comes from the reliability and safety point of view. The underneath ceramic core offers extra thermal protection in case of the failure or underestimated design of the ablative external protections (see reference of the Galieo’s Probe). An accompanying effect is also the lower contamination during all mission phases and especially during re-entry.

INTRODUCTION AND MOTIVATION

08-04-2013 / 4

The concept of the project is based on the development of a novel hybrid heatshield, based on the integration of an external ablative parts with a CMC thermostructural core. This will be carried out by the integration of dissimilar materials.

The main advantage of a hybrid TPS heat-shield is based on the capability of the ablative layer of the hybrid TPS of bearing higher heat loads than the ceramic layer underneath.

The main challenge is to achieve a sound bonding among the two parts. This will be carried-out by advanced bonding technologies. This will be carried out by the study and development of new adhesives solutions, with improved mechanical and insulating characteristics. The use of advanced high temperature adhesives and hybrid solutions in combination with mechanical attachments will be assessed, as well as other existing hybrid solutions.

Ablative external shield

CMC core

Joining region & InterfaceAblative external shield

CMC core

Joining region & Interface

CMC core

Joining region & Interface

CONCEPT OF THE PROJECT

08-04-2013 / 5CONCEPT OF THE PROJECT

Heatflux

T (sec)

Interfacetemp,

limit 1200 ºC

Timeablative full burn-out

Ablative based re-entry CMC based re-entry

Heatfluxpeak,

From this point of view it will offer improved mechanical properties as well as higher robustness during the entry. Besides, the new moon or interplanetary missions planned cause higher heat loads during earth re-entry than ceramic or metallic TPS can withstand, since these heat loads are characterized by a peak profile the ablator can bear the high heat loads during the peak. For that a comparatively thin layer of ablative material is sufficient. The large integral loads will then be overtaken by the ablative/ceramic interfacial layer.

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CONSORTIUM MEMBERS LOCATION

1 - TECNALIA (Coordinator)

The core group of HYDRA project is composed of 10 public and private organisations coming from 5 different European countries: France, Greece, Germany, Romania and Spain.

3 – ASTRIUM-F

6 – HPS

7 – DEMOKRITOS

9 – ICMCB4 – HPK

2 – ASTRIUM-G

5 – DLR

10 – IRS

8 – INCAS

CONSORTIUM

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Part.No.Part. Short

NameProfile Relevant expertise for the project Role in the project WPs Involvement

1 TECNALIA Research centreCeramic composite materials design, processing, bonding terisation. Background on disseminations and technology transfer.

Coordination, materials developer, materials joining, centre in charge of dissemination actions.

WP2, WP5, WP8, WP9. Technical coordination in (WP1, WP3, WP4, WP6,

Wp7)

2 ASTRIUM-GEnd user, large company,

large system integrator

CMC material development, design, analysis, manufacturing & flight/ground testing as well as application

Developing, designing, manufacturing and characterization testing of C/SiC CMC's.

WP4, WP8

3 ASTRIUM-F End user, large company

Knowledge of management of atmospheric entry programs. Competence in heatshield thermal protection materials : development, production, characterisation, modelling and analysis

Mission specification, Material developer and producer, heatshield analysis

WP1, WP3, WP6, WP8

4 HPK SME, material supplierCork composite materials (formulations and manufacturing), tooling, bonding, moulding and prototyping

Ablative cork materials and TPS breadboard part supplier.

WP3, WP8

5 DLRResearch centre, space systems manufacturer,

DLR is the German space agency. CMC material development and charactersiation

Developing, designing, manufacturing and characterization testing of C/C-SiC CMC's. Characterisation of hybrid joints.

WP4, WP5, WP6, WP7, WP8

6 HPS SME, technology providerTPS technology provider. Konow-how on

materials selection.Technology advisory. Engineering consulting.

WP2, WP5, WP6, WP7, WP8

7 NCSRD Research centreAblative-ceramic joining. Ceramic composite

materials characterization & coatings.Materials joining and characterization.

WP3, WP4, WP5, WP7, WP8.

8 INCAS Research centre

Composite materials CFRP, C-C composite and partially ceramic matrix design,

processing, thermo-mechanical characterisation and morfostructural

investigation

Characterisation of space materials

WP7, WP8

9 ICMCB Research centreNumerical modeling of coupled phenomenon occurring at local scale, 3D imaging of multi

materialsModelling and characterisation WP6, WP7, WP8

10 IRS UniversityCharacterisation of TPS comments and hot

structures.

Ground re-entry characterisation and validation of the technology sample

WP1, WP7, WP8

CONSORTIUM

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WP1WP1

Mission Profile & TPS specs

WP2WP2

SoA & Materials Trade-off

WP

8W

P8

Use

, Exp

lota

ition

& D

isse

min

atio

n WP3WP3

Ablative Protection Shield

WP4WP4

Structural Ceramic Core

WP5WP5

Full TPS assembly

WP6WP6

Modeling, Simulation and Design

WP7WP7

Charac., Re-entry test & Validation

WP

9W

P9

Financial M

anagem

ent

RTD

MANAGEMENT

OTHER

WP1WP1

Mission Profile & TPS specs

WP2WP2

SoA & Materials Trade-off

WP

8W

P8

Use

, Exp

lota

ition

& D

isse

min

atio

n WP3WP3

Ablative Protection Shield

WP4WP4

Structural Ceramic Core

WP5WP5

Full TPS assembly

WP6WP6

Modeling, Simulation and Design

WP7WP7

Charac., Re-entry test & Validation

WP

9W

P9

Financial M

anagem

ent

RTD

MANAGEMENT

OTHER

WORKPACKAGE: STUDY LOGIC

08-04-2013 / 9SCHEDULE STATUS

Status at M13

WP No. Feb

ruar

y 20

12

Mar

ch 2

012

Apr

il 20

12

May

201

2

June

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2

July

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2

Aug

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2012

Sep

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2012

Oct

ober

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2

Nov

embe

r 20

12

Dec

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r 20

12

Janu

ary

2013

Feb

ruar

y 20

13

Mar

ch 2

013

Apr

il 20

13

May

201

3

June

201

3

July

201

3

Aug

ust

2013

Sep

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2013

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3

Nov

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r 20

13

Dec

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r 20

13

Janu

ary

2014

Feb

ruar

y 20

14

Mar

ch 2

014

Apr

il 20

14

May

201

4

June

201

4

July

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4

Aug

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2014

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Janu

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15

WP1 Mission review, trade-off, selection and TPS specs M1WP1.1 Mission ProfileWP1.2 TPS specificationsWP2 State-of-the-art & Materials trade-off M2WP2.1 State-of-the-artWP2.2 Materials trade-offWP3 Ablative protection shield M3WP3.1 Advanced ablative materials based on resinsWP3.2 Advanced ablative materials based on corkWP3.3 Manufacture of heat-shield partsWP4 Stuctural ceramic core M4WP4.1 Ceramic core development & characterizationWP4.2 Ceramic core concept verification & demonst.WP5 Full protection system assembly M5WP5.1 Definition of bonding processesWP5.2 Ablative/ceramic frames joiningWP5.3 Fabrication of TPS breadboardWP5.4. Testing & characterisation of the jointWP6 Modelling, simulation & TPS design M6WP6.1 Simulation of the oxidationWP6.2 Hybrid thermal modelling of the hybrid conceptWP6.3 TPS final designWP7 Characterisation, re-entry and validation M7WP7.1 Microstructural and Thermo-mechanical chara.WP7.2 Re-entry testingWP7.3 Validation of the envisaged TPS conceptWP8 Use, exploitation and dissemination M8WP8.1 Dissemination activities planWP8.2 Use planWP9 Financial management, coord. and reportingWP9.1 AdministrativeWP9.2 Financial

Year 1 Year 2 Year 3

08-04-2013 / 10MATERIALS TESTING & CHARACTERISATION PLAN

AST-F Manufacture of 10 ASTERM plates

(550 x 550 x 70 mm)

HPK Manufacture of 10 NORCOAT LIEGES

plates(550 x 550 x 70 mm)

AST-G Manufacture of SICARBON samples

1 m2 in different pannels, 5mm

DLR Manufacture of C-C/SiC samples

1 m2 in different pannels, 5mm

TECNALIA•Materials machining•Basic Thermal & Mechanical Characterisation•Gluing & Joining• Materials & Breadboard store

ICMCB - Thermal Characterisation:Only ablators Laser Flash (RT - 1100)Linear Dilatometry (RT-1600 ºC).(No. samples & Dimension TBD)

INCAS – Thermo-mechanical:Compression & Flexural (RT)Thermal shock QST2 (RT-1500 ºC)Microstructural study< 75 samples & 30 x 50 x 10 mm

NCRSD Neutron Tomography20 samples, Ø 40 x 40 mm aprox (special assembly). Before and after PWT

NCRSD Additional testing & surface treatments (K. Mergia)Ablative-ablative interfaces (G. Veknis)

DLRThermo-mechanical at INDUTHERM facility (RT-2000ºC)X-Ray tomography45 sa mples - 60x 60 x 60

IRSPlasma Wind Tunnel. 20 samples, Ø 39.8 x 40 mm aprox (special assembly)Emissivity (few samples are possible)

MANUFACTUREWP3 & WP4

ASSEMBLYWP5

CHARACTERISATION WP7

HPK“in-situ” Cork Composite manufacture on top of a

CMC plate

08-04-2013 / 11

Mission review and trade-off (by Astrium SAS): analysis of the current mission and European roadmaps for planetary re-entry

MISSION REVIEW AND TPS SPECIFICATIONS

08-04-2013 / 12

Final selection based on Earth re-entry: CSTS (from Low lunar orbit) and CTV/ARV (from ISS)

CSTS (Credit Astrium GmbH)CTV/ ARV (Credit Astrium SAS)

MISSION REVIEW AND TPS SPECIFICATIONS

08-04-2013 / 13MISSION REVIEW AND TPS SPECIFICATIONS

CTV/ARV (CREW TRANSFER VEHICLE / ADVANCED RE-ENTRY VEHICLE)

Control Points Heatflux evolution

Local stagnation pressure Heat-flux vs. Local stagnation pressure

08-04-2013 / 14MISSION REVIEW AND TPS SPECIFICATIONS

Control Points Heatflux evolution

Local stagnation pressure Heat-flux vs. Local stagnation pressure

CSTS (CREW SPACE TRANSPORTATION SYSTEM)

08-04-2013 / 15MISSION REVIEW AND TPS SPECIFICATIONS

Set of requirements defined with regards to the following criteria:

08-04-2013 / 16MATERIALS STATE OF THE ART AND TRADE-OFF

State of the art considering:

Analysis of previous “hybrid” concepts: SEPCORE® (ablator on top), SPA (CMC on top), HybridTPS (Porous ceramic infiltrated). Review of ablative materials at worldwide level with emphasis on European supplier. Locate the project partners in this state-of-the-art

Trade-off Consider relevant ablative TPS materials at worldwide level. Elaborate a TPS material selection matrix -> Trade-off criteria Establish a materials ranking Locate project partner in the ranking Tailor this selection matrix to mission definition from WP1

SEPCORE® (Herakles) SPA (Astrium GmbH)

08-04-2013 / 17MATERIALS SELECTION & PROCUREMENT

Two types of phenolic ablator envisaged for the project:

Cork based materials: NORCOAT FI (backshield) Graphite based materials: ASTERM (frontshield)

NORCOAT

(HPK Liéges)

ASTERM

(Astrium SAS)

08-04-2013 / 18

Two manufacturers CMC (Cf/SiC) envisaged for the project:

C/C-SiC (from DLR stuttgart). SICARBON© (EADS)

C/C-SiC

(DLR)

(EADS)

MATERIALS SELECTION & PROCUREMENT

08-04-2013 / 19

Selection of materials combination

FRONT SHIELD

Hybrid TPS selected

ASTERM+

SICARBON

Ablative external shield

CMC core

Joint at 100-150 ºCAblative external shield

CMC core

Joint at 100-150 ºC

CMC core

Joint at 100-150 ºC

EADS DLR + HPK

BACK SHIELD

NORCOAT+

C/C-SiC

BONDING & TPS ASSEMBLY

08-04-2013 / 20BONDING & TPS ASSEMBLY

Selection of adhesive:

Inorganic based adhesive for the ablator/ceramic joint Organic adhesive for the ablator/ablator interface Criteria of selection:

o Performance at the different phases (launching, ascent, re-entry)o Nature of the inorganic filler (alumina, silica, graphite, etc..)o Wettability with the surfaceso Curing temperatureo Ablator/ceramic interface temperature (aided by modeling)o Thermal properties (CTE, Thermal conductivity)

First stage of the re-entry

Ablative external shield

CMC core

Joint at 100-150 ºCAblative external shield

CMC core

Joint at 100-150 ºC

CMC core

Joint at 100-150 ºCJoint at 1500 ºC?Charred Ablator

CMC core

Second stage of the re-entry

08-04-2013 / 21SIMULATION & TPS DESIGN

Simulation at different levels:

Local thermo-chemical modelo At the micro/nano rangeo Aided by 3D model technologies by the use of a nano-tomographic system (ICMCB)

1D Thermal ablation model (Astrium SAS) -> Assessment of ablator thickness and interfacial temperature -> Lecture by G. Pinaud. Thermal analysis (2D model) -> Materials properties as input

TPS Design

Tile breadboard:o Foreseen dimensions of 100 mm x 100 mm (planar)o Including ablator/ablator joints and ablator/ceramic bonding.

Further mass saving calculation wrt a whole capsule vehicle (i.e. CTV/ARV)

Local model on ablators 1D model (thickness vs. interface temperature and recession)

08-04-2013 / 22CHARACTERISATION & VERIFICATION PLAN

Characterization of materials and bonded structures:

ASTERM ablator. Full characterization of thermal and mechanical propertieso Emissivity, coefficient of thermal expansion, specific heat, thermal diffusivity and

conductivityo Tensile, compressive and flexural strength (including cryogenic temperatures)

Adhesive:o First screening based on bonding results and shear strength testo Second screening based on thermal shock (QST-2 at INCAS) and cyclic test at

INDUTHERM (DLR Stuttgart)o Final selection based on the performance and the plasma wind tunnel (correlation with

WP1 specifications). Final test of the breadboard at the PWT (IRS, Stuttgart). Comparison of perfirmace vs. requirements.

Shear test at NCSR “Demokritos”Thermal schock furnace at INCAS

08-04-2013 / 23CHARACTERISATION & VERIFICATION PLAN

Cyclic test at INDUTHERM (DLR Stuttgart)

08-04-2013 / 24CHARACTERISATION & VERIFICATION PLAN

Final test of the breadboard at the PWT (IRS Stuttgart):

08-04-2013 / 25CHARACTERISATION & VERIFICATION PLAN

Final test of the breadboard at the PWT (IRS Stuttgart):

o Facility PWK2 for CTV/ARV conditionso Facility PWK1 for CSTS, using either RD5 or RD7 as plasma source for 5.7 MW/m2 condition

08-04-2013 / 26MAIN CONCLUSIONS AND FUTURE WORK

HYDRA is a new TPS concept that combines a low density ablator and a underneath hot substructure.

Main advantages are:1) Mass reduction as compared with a solution based on a single ablator solution, while 2) Increase the temperature limits as compared with a re-usable system

The project is running for one third of the total duration, the mission is selected, the requirements complied and the characterisation/verification plan is ready.

The materials trade-off is almost finished and the materials are have been just procured to the partners. The simulation phase and bonding study has been initiated.

Future effort will include the selection of the adhesive based on a complete screening study (2 nd year) and the execution of the verification plan (3 rd Year) including characterisation under Plama Wind Tunnel conditions.

A mass saving analysis will be carried-out with regards to a full shield concept.

08-04-2013 / 27ACKNOWLEDGMENTS

European Space Agency (M. Bottacini and B. Jeusset)

European Commission

Research Executive Agency (C. Ampatzis)

EADS-Innovation Works (C. Wilhelmi).

NCSRD (K. Triantou).

IRS (T. Marynowski)

ASTRIUM SAS (Y. Aspa)

08-04-2013 / 28

For more details visit the Project webpage: www.hydra-space.eu

WEB PAGE

08-04-2013 / 29

END OF PRESENTATION

Many thanks for your attention