CARBON-PHENOLIC ABLATORS. Industrial status and potential applications. 7 th European Workshop on TPS & HS th April 2013

Transcription

1 CARBON-PHENOLIC ABLATORS Industrial status and potential applications R. Barreteau T. Pichon M. Lacoste 7 th European Workshop on TPS & HS 8-10 th April 2013

2 /01/ C-PHENOLIC ABLATORS DESIGN AND MANUFACTURING AT HERAKLES 1 /

3 CARBON-PHENOLIC HERITAGE IN HERAKLES Large heritage from solid rocket motors (SRMs) application of fibre-reinforced polymers TPS Started in the 60 s for solid rocket propulsion (military application) Technology matured through several generations of rocket engines and extended to larger scale for Ariane 5 SRMs Continuous development effort of sizing tools (incl. thermo-chemical ablation models) and manufacturing processes C-Phenolic TPS 2 /

4 CURRENT PRODUCTION : STANDARD 2D C-PHENOLIC C-phenolic ablators based on 2D reinforcement are still widely manufactured : Large existing database and flight experience High thermal insulation performance in harsh environments (> 10 MW/m²) Sustainability of carbon-phenolic has been consolidated Up to end of 1990s, use of US (NARC) rayon as precursor of carbon fabric After shutdown of US production, alternative sources identified, focusing on sustainable rayon grade (e.g. high tenacity rayon used in automotive industry) Dedicated production tool invested by Herakles : carbon fabric Raycarb C2 is now under production (>20-30 tons per year) 3 /

5 CURRENT PRODUCTION : ADVANCED C-PHENOLIC Improvements developed from beginning of 2000s Replacement of ex-rayon by ex- PAN tape Replacement of pre-preg wrapping process by 3D (needled) carbon reinforcement Main benefits : Increased delamination resistance Decreased need for structural parts on the rear face of the ablator (metal housing for nozzles) Introduction of more economic manufacturing processes (precursor, RTM, ) 3D (left) and 2D (right) C-phenolic after firing test 4 /

6 STATE OF THE ART FOR ROCKET ABLATORS Advanced C-phenolic material (NAXECO -Resin) developed for Vega P80 Successful qualification through ground firing tests and launcher maiden flight Production line in service for Vega programme Standard C-phenolic Advanced C-phenolic 5 /

7 /02/ C-PHENOLIC TPS FOR RE-ENTRY APPLICATIONS 6 /

8 TPS NEEDS FOR EXPLORATION MISSIONS Flight heritage shows that past re-entry heat shields used different categories of ablators Light ablators (d < ~500 kg/m 3 ) for atmospheric entry in Earth : Moon return (Apollo), comet sample return (Stardust), Mars (various landers) and Titan (Huygens) atmospheres Dense ablators (d ~1500 kg/m 3 ) for atmospheric entry in Venus (Pioneer Venus) and Jupiter (Galileo) atmospheres Strong interest still present for scientific missions with atmospheric phase : Entry in Mars, Venus, Jupiter, Saturn, Titan, Neptune atmospheres for in-situ observations Aero-capture manoeuvres in Mars or giant planet atmospheres (Saturn Ring Observer) Earth atmosphere re-entry for return of samples : NEOs (MARCO POLO-R), Mars (Mars Sample Return), comets, 7 /

9 SUITABILITY OF C-PHENOLIC FOR FUTURE PROBE MISSIONS IN THE SOLAR SYSTEM Large agreement in TPS community that demanding missions such as Venus and giant planet entry / aero-capture can only use dense ablators, such as C-phenolic Mission type Planet Atmospheric entry Aerocapture Sample return to Earth Entry velocity (km/s) Peak heat Flux (kw/m²) C-phenolic suitability Lightweight ablator suitability Venus 10 [a] [a] Yes No Mars 5,7 [a] 500 [a] Yes (heavy) Yes Jupiter 60 [a] [a] Yes No Saturn 28.6 [b] [b] Yes No Titan 6 [b] [b] Yes (heavy) Yes Mars 4 [c] 160 [c] Yes (heavy) Yes Saturn 28.6 [b] [b] Yes No Neptune 30 [d] [d] Yes No Mars [a] [a] Yes to be confirmed NEO 12 [a] [a] 5000 Yes to be confirmed [e] [e] [a] Lacoste et al., Sustainable c-phenolic ablative material for the Ariane 5 SRM motor and application to TPS for entry probes, 5th TPS Woorkshop, 2006 [b] Venkatapathy et al., Thermal protection system development, testing, and qualification for atmospheric probes and sample return missions - Examples for Saturn, Titan and Stardust-type sample return, Advances in Space Research, 2008 [c] [d] Requis ton et al., AEROFAST: Aerocapture for future space transportation, International Planetary Probe Workshop (IPPW-7), 2010 Park, Stagnation-point radiative heat fluxes in Neptune aerocapture, International Planetary Probe Workshop (IPPW-7), 2010 [e] Venkatapathy et al., Thermal Protection System Technologies for Enabling Future Sample Return Missions, White paper to the NRC decadal primitive bodies s ub-panel, /

10 SUITABILITY OF C-PHENOLIC FOR FUTURE PROBE MISSIONS IN THE SOLAR SYSTEM (CONTINUED) One main drawback high density C-phenolic best candidate for direct entry or aerocapture C-phenolic well-suited for sample return but many advantages : Good resistance to MMOD impacts Very high reliability due to large flight heritage (adapted to high value, complex exploration missions (e.g. return of samples to Earth) Availability, sustainability C-phenolic will be applied on European launcher in the next decades, Existing manufacturing facility in Herakles are compatible of most heat-shield sizes (typically from 1 to 2 m in diameter in foreseeable missions) Numerous lightweight ablators, produced specifically for probe heat-shield application, have met disruption in manufacturing capacity, leading to long and costly re-qualification process Saturn Mars NEOs Venus Jupiter Outer giant planets 9 /

11 /03/ THE SEPCORE ADVANCED TPS DESIGN 10 /

12 WHAT IS SEPCORE? Advanced TPS concept providing significant weight reduction by use of higher temperature-capable support structure : Outer component made of C-phenolic (other types of ablators can be considered) Hot structure made of thermo-structural material (C-C or C-SiC) provide mechanical support, fastening being made through thermo-mechanical bolts Lightweight internal insulation (e.g. multilayer insulation) 11 /

13 SEPCORE TESTING First design and PWT tests performed in 1990s within ESA TRP Mock-up manufactured with C-SiC structure PWT test in PWK1 facility in IRS : peak heat flux of 10 MW/m² at stagnation point Demonstrated satisfactory thermal and mechanical behaviour of both ablative and thermo-structural layer on a significant scale ( 300 mm) 12 /

14 SEPCORE PERFORMANCE Different conceptual designs performed for various TPS mission profiles ROSETTA probe (peak heat flux ~10 MW/m²) : -30% mass reduction (taking into account C-phenolic, structure and internal insulation) compared to standard heat shield design (C-phenolic bonded on aluminium or CFRP structure) Jupiter entry probe (peak heat flux ~350 MW/m²) : >25% reduction of C-phenolic mass necessary Apollo-like heat shield for Moon return : -40% mass compared to standard design if C-phenolic ablator used on top of C-SiC shingles, -50% mass if integral C-SiC structure used in place of CFRP cold structure 13 /

15 HOT STRUCTURE TECHNOLOGY AT HERAKLES Hot structures made of thermostructural materials developed since 1980s Available materials comprise C-C and C- SiC, manufactured at industrial scale for aeronautics and space applications : C-SiC nozzle flaps for Rafale fighters C-C and C-SiC nozzles for upper stage rocket engines (RL10-B2 and Vinci engines) C-C nozzle throat for solid motors nozzle throats (incl. MPS and Vega stages) Re-usable thermal protection system for entry vehicles (IXV) : significantly increased level of maturity through development and manufacturing of Qualification and Flight Models 14 /

16 CONCLUSION Decade-long development and industrial production of C-phenolic ablators at Herakles for solid rocket propulsion components Up-to-date ablation modelling and ablator sizing capacity Sustainable manufacturing chain established and qualified for C fabric (space grade), providing off-the-shelf European C-phenolic ablator Continuous improvement of C-phenolic technical performance and reduction of costs through state-of-the-art processes Wide range of C-phenolic potential applications in space exploration Direct entries or aero-capture in harsh atmospheric environment (Venus, Jupiter, Saturn, Neptune) Samples return from Mars, comets or NEOs into Earth atmosphere Any application where high reliability or low development cost is a major driver Mass decrease of C-phenolic base heat shields can be reached through development of advanced TPS concepts (SEPCORE ) use of standard C-phenolic and CMC hot structures (high level of maturity through rocket nozzles and IXV TPS) 30 to 50% mass reduction compared to standard C-phenolic heat shield concept can be reached, extending the mission range of potential missions for C-phenolic 15 /