The Space Shuttle Thermal Protection System Daniel Kwon 16.885J Final Presentation December 6, 20052Space Shuttle Thermal Protection System Outline  Requirements and design  TPS performance and evaluation  New requirements  Maintenance techniques  New technology  Conclusions3Space Shuttle Thermal Protection System TPS requirements  Orbiter structure temperature < 350° F  Reusable for 100 missions  Maintain integrity  Acceptable aerodynamic surface  Minimal weight, maintenance, and refurbishment4Space Shuttle Thermal Protection System Design summary: Ceramic Tiles  High purity silicon    Reaction cured glass (RCG) coating  SIP  Room Temperature Vulcanizer (RTV)  Gap Fillers HRSI – black LRSI – white5Space Shuttle Thermal Protection System Design summary: RCC  Leading edge structure system (LESS) and nose cap  All-carbon composite: rayon cloth graphitized &impregnated with resin polymer  Regions of orbiter > 2300° F  Operational temp. of -200 to 3000° F  LESS consists of 22 RCC panels  RCC parts form a hollow shell Æ internal radiation6Space Shuttle Thermal Protection System Performance Summary  Overall, measured surface temperatures lower than requirement, and lower than predicted  Some areas of excessive tile-to-tile heating (gap filler fix)  Excellent mechanical performance   Recommend similar system (SIP, RTV) for future designs Test phase: no tiles from underneath detached, small amount of damage to tiles, some LRSI tiles fell off7Space Shuttle Thermal Protection System Evaluation  Positive aspects  Extremely good thermal performance  Reusable  Ease of maintenance  Negative aspects  Low impact resistance  Loss of gap fillers (localized heating)8Space Shuttle Thermal Protection System New Requirements 1. Maintain higher amount of structural integrity 2. Tile condition must be easily monitored during a mission 3. TPS must have on-orbit repair capabilities 4. Reduced maintenance to reduce costs9Space Shuttle Thermal Protection System Meeting maintenance requirements  Challenges:  Large number of components: > 30,000  Complex tile acceptance logic New Techniques  On-orbit maintenance  repair kit (GRABER), SAFER propulsion system, laser topography sensor  Rapid Re-Waterproofing  Electronic tracking (maintenance) system Backflip maneuver, Tile repair kit, RCC10Space Shuttle Thermal Protection System TUFI: Toughened Uni-Piece Fibrous Insulation  Ceramic tile concept developed by NASA Ames  Coated with Alumina Enhanced Thermal Barrier (AETB)  Same SIP, RTV used  1-2 order of magnitude more resistant to damage  Maximum operational temp = 2500° F11Space Shuttle Thermal Protection System Blanket Insulation: TABI and CRI  Silica-based blanket type TPS  Upgrades to FRSI  Quilted blankets with integrated ceramic  Improve strength and outer surface   Ceramic fiber with Q-fiber felt insulation   Ceramic matrix composite Tailorable Advanced Blanket Insulation (TABI) – NASA Ames Conformal Reusable Insulation (CRI) - Boeing12Space Shuttle Thermal Protection SystemMetallic TPS Lightweight metallic structure enclosing a high-efficiency fibrous insulation ARMOR (Adaptable Robust Metallic Operable Reusable) TPS – NASA LaRC Inconel honeycomb structure enclosing Saffil insulation More damage tolerant, but lower operational temperatures13Space Shuttle Thermal Protection System Metallic TPS, con’t  Several variation of Metallic TPS exist  Honeycomb material  Inconel, Titanium, other alloys  Insulation layer   ° F Saffil, Internal Multiscreen Insulation (IMI) Operational temperature: 2000 - 220014Space Shuttle Thermal Protection System Hot Structures  Metallic primary structure acts as a heat sink  Integrated structure and TPS Æ large mass savings  Progress highly dependant on materials research and fabrication processes  Operational temperatures ~1500° F  Candidate systems  Gamma Titanium aluminide (TiAl)  Metal matrix composites  Nickel metal foam15Space Shuttle Thermal Protection System Conclusions  TUFI tile system replaces HRSI  TABI systems used to upgrade FRSI  No RCC replacement  Metallic TPS have high future potential  Improved maintenance techniques currently in practice current requirements RCC High Durability High Temp. HRSI LRSI FRSI new requirements TUFI TABI Hot Structures Metallic TPS16Space Shuttle Thermal Protection System Interfaces 1: Interactions between shuttle subsystems  Structures  Aerodynamics  Environmental control system  Guidance, Navigation, & Control  External Tank and Solid Rocket