{
  "spore": "profile",
  "id": "frsi-nomex-felt-blanket",
  "spore_version": "0.2",
  "family": "glass-and-composites",
  "name": "FRSI (felt reusable surface insulation, coated Nomex felt)",
  "abbreviation": "FRSI",
  "role": "thermal-protection-blanket",
  "category": "thermal-protection",
  "type": "flexible-blankets",
  "summary": "FRSI is a white, flexible blanket of heat-treated Nomex felt with a white silicone elastomer coating. NASA used it on Space Shuttle orbiter upper surfaces where temperatures stayed below about 700 °F. NASA sources give its emittance as 0.8 and its solar absorptance as 0.32. Its density and thermal conductivity are printed in the NASA database only in exponent form, so this profile leaves them out.\n",
  "best_for": "White blanket insulation for areas below about 700 °F on a re-entry vehicle, where an emittance of 0.8 is wanted",
  "weakest_at": "Few plain numbers for the blanket itself: the NASA database prints density, conductivity and temperature limits only in exponent form, so they are left out",
  "identity": {
    "formula": "Heat-treated meta-aramid (Nomex) felt with a white silicone elastomer coating; the polymer is made from m-phenylenediamine and isophthaloyl chloride",
    "designations": [
      {
        "system": "Trade name",
        "code": "Nomex",
        "source": "dupont-nomex",
        "where": "Page text naming DuPont Nomex and its felt form"
      }
    ],
    "source": "wiki-nomex",
    "where": "Chemistry paragraph (monomers); the Shuttle use is in the Wikipedia Space Shuttle TPS article"
  },
  "tags": {
    "environments": [
      "re-entry",
      "low-earth-orbit"
    ],
    "stresses": [],
    "applications": [
      "heat-shields"
    ]
  },
  "properties": [
    {
      "benchmark": "thermal_emittance",
      "label": "Emissivity (NASA TPSX table)",
      "value": 0.8,
      "bound": "exact",
      "unit": "-",
      "scope": "material",
      "conditions": {
        "table": "Properties at Standard Conditions (SI units)",
        "stated_condition": "true/assumed",
        "ref_column": "2"
      },
      "method": "Tabulated value in the NASA Ames TPSX database entry; the same row prints an uncertainty of 0.04",
      "status": "ground",
      "uncertainty": "0.04 (printed in the same row)",
      "source": "tpsx",
      "where": "Properties at Standard Conditions table, row Emissivity",
      "source_detail": {
        "title": "NASA Ames Thermal Protection Materials database: FRSI Blanket (Nomex Felt)",
        "url": "https://tpsx.arc.nasa.gov/Material?id=18",
        "kind": "database",
        "license": "Public domain (NASA)"
      }
    },
    {
      "benchmark": "thermal_emittance",
      "label": "Emittance of FRSI (NASA shuttle systems text)",
      "value": 0.8,
      "bound": "exact",
      "unit": "-",
      "scope": "material",
      "conditions": {
        "context": "Stated for FRSI in the same sentence as the solar absorptance of 0.32"
      },
      "method": "Value stated in NASA KSC shuttle systems text",
      "status": "ground",
      "source": "ksc-sts-sys",
      "where": "Section on Felt Reusable Surface Insulation",
      "source_detail": {
        "title": "Space Shuttle systems, KSC shuttle technology page (archived copy, 2009 snapshot)",
        "url": "https://web.archive.org/web/20090715235829/http://science.ksc.nasa.gov/shuttle/technology/sts-newsref/sts_sys.html",
        "year": 2009,
        "kind": "report",
        "license": "Public domain (NASA)"
      }
    },
    {
      "benchmark": "solar_absorptance",
      "label": "Solar absorptance of FRSI",
      "value": 0.32,
      "bound": "exact",
      "unit": "-",
      "scope": "material",
      "conditions": {
        "context": "Stated in the same sentence as the emittance of 0.8"
      },
      "method": "Value stated in NASA KSC shuttle systems text",
      "status": "ground",
      "source": "ksc-sts-sys",
      "where": "Section on Felt Reusable Surface Insulation",
      "source_detail": {
        "title": "Space Shuttle systems, KSC shuttle technology page (archived copy, 2009 snapshot)",
        "url": "https://web.archive.org/web/20090715235829/http://science.ksc.nasa.gov/shuttle/technology/sts-newsref/sts_sys.html",
        "year": 2009,
        "kind": "report",
        "license": "Public domain (NASA)"
      }
    },
    {
      "benchmark": "thickness",
      "label": "FRSI thickness on the orbiter (range set by heat load)",
      "value": 0.16,
      "value_high": 0.4,
      "bound": "range",
      "unit": "inch",
      "scope": "material",
      "conditions": {
        "depends_on": "Heat load encountered during entry",
        "form": "Installed FRSI blanket"
      },
      "method": "Range printed in NASA KSC shuttle systems text",
      "status": "ground",
      "source": "ksc-sts-sys",
      "where": "Section on Felt Reusable Surface Insulation",
      "source_detail": {
        "title": "Space Shuttle systems, KSC shuttle technology page (archived copy, 2009 snapshot)",
        "url": "https://web.archive.org/web/20090715235829/http://science.ksc.nasa.gov/shuttle/technology/sts-newsref/sts_sys.html",
        "year": 2009,
        "kind": "report",
        "license": "Public domain (NASA)"
      }
    },
    {
      "benchmark": "thickness",
      "label": "FRSI thickness on the orbiter (TPSX description)",
      "value": 0.16,
      "value_high": 0.4,
      "bound": "range",
      "unit": "inch",
      "scope": "material",
      "conditions": {
        "depends_on": "Heat load encountered during re-entry",
        "form": "Installed FRSI blanket"
      },
      "method": "Range printed in the NASA Ames TPSX description",
      "status": "ground",
      "source": "tpsx",
      "where": "Description paragraph",
      "source_detail": {
        "title": "NASA Ames Thermal Protection Materials database: FRSI Blanket (Nomex Felt)",
        "url": "https://tpsx.arc.nasa.gov/Material?id=18",
        "kind": "database",
        "license": "Public domain (NASA)"
      }
    },
    {
      "benchmark": "coating_thickness",
      "label": "Silicone elastomer coating, as spread before cure",
      "value": 0.006,
      "value_high": 0.008,
      "bound": "range",
      "unit": "inch",
      "scope": "material",
      "conditions": {
        "process": "Elastomer spread on a screen mesh, then partially cured",
        "form": "Heat-treated Nomex felt"
      },
      "method": "Process range printed in the NASA Gordon appendix A.4; a process value, not a finished-coating measurement",
      "status": "ground",
      "source": "gordon",
      "where": "A.4 Felt Reusable Surface Insulation, coating paragraph",
      "source_detail": {
        "title": "Shuttle thermal protection system, Appendix A (NASA KSC public appendix, archived copy)",
        "url": "https://web.archive.org/web/20160307090308/http://science.ksc.nasa.gov/shuttle/nexgen/Nexgen_Downloads/Shuttle_Gordon_TPS-PUBLIC_Appendix.pdf",
        "kind": "report",
        "license": "Public domain (NASA)"
      }
    },
    {
      "benchmark": "vent_hole_diameter",
      "label": "Vent hole diameter in the FRSI coating",
      "value": 0.035,
      "bound": "exact",
      "unit": "inch",
      "scope": "material",
      "conditions": {
        "feature": "Vent holes through the white coating"
      },
      "method": "Printed in the NASA Gordon appendix A.4",
      "status": "ground",
      "source": "gordon",
      "where": "A.4, last paragraph",
      "source_detail": {
        "title": "Shuttle thermal protection system, Appendix A (NASA KSC public appendix, archived copy)",
        "url": "https://web.archive.org/web/20160307090308/http://science.ksc.nasa.gov/shuttle/nexgen/Nexgen_Downloads/Shuttle_Gordon_TPS-PUBLIC_Appendix.pdf",
        "kind": "report",
        "license": "Public domain (NASA)"
      }
    },
    {
      "benchmark": "vent_hole_spacing",
      "label": "Vent hole spacing in the FRSI coating",
      "value": 6,
      "bound": "exact",
      "unit": "inch",
      "scope": "material",
      "conditions": {
        "feature": "Vent holes through the white coating",
        "spacing": "On 6 inch centers, as printed"
      },
      "method": "Printed in the NASA Gordon appendix A.4",
      "status": "ground",
      "source": "gordon",
      "where": "A.4, last paragraph",
      "source_detail": {
        "title": "Shuttle thermal protection system, Appendix A (NASA KSC public appendix, archived copy)",
        "url": "https://web.archive.org/web/20160307090308/http://science.ksc.nasa.gov/shuttle/nexgen/Nexgen_Downloads/Shuttle_Gordon_TPS-PUBLIC_Appendix.pdf",
        "kind": "report",
        "license": "Public domain (NASA)"
      }
    },
    {
      "benchmark": "max_service_temp",
      "label": "Upper temperature for FRSI areas (design envelope, Gordon appendix)",
      "value": 750,
      "bound": "upper",
      "unit": "°F",
      "scope": "material",
      "conditions": {
        "context": "Upper surface areas where FRSI is used; design envelope, not a material test limit"
      },
      "method": "Application limit printed in the NASA Gordon appendix A.4 as less than 750°F",
      "status": "ground",
      "source": "gordon",
      "where": "A.4, first paragraph",
      "source_detail": {
        "title": "Shuttle thermal protection system, Appendix A (NASA KSC public appendix, archived copy)",
        "url": "https://web.archive.org/web/20160307090308/http://science.ksc.nasa.gov/shuttle/nexgen/Nexgen_Downloads/Shuttle_Gordon_TPS-PUBLIC_Appendix.pdf",
        "kind": "report",
        "license": "Public domain (NASA)"
      }
    },
    {
      "benchmark": "max_service_temp",
      "label": "Upper temperature for FRSI areas (design envelope, KSC shuttle systems text)",
      "value": 700,
      "bound": "upper",
      "unit": "°F",
      "scope": "material",
      "conditions": {
        "context": "Areas the FRSI blankets protect; design envelope, not a material test limit"
      },
      "method": "Application limit printed in NASA KSC shuttle systems text",
      "status": "ground",
      "source": "ksc-sts-sys",
      "where": "Numbered item 6, White blankets of coated Nomex felt",
      "source_detail": {
        "title": "Space Shuttle systems, KSC shuttle technology page (archived copy, 2009 snapshot)",
        "url": "https://web.archive.org/web/20090715235829/http://science.ksc.nasa.gov/shuttle/technology/sts-newsref/sts_sys.html",
        "year": 2009,
        "kind": "report",
        "license": "Public domain (NASA)"
      }
    },
    {
      "benchmark": "max_service_temp",
      "label": "Upper temperature for FRSI areas (AZoM article)",
      "value": 371,
      "bound": "upper",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "context": "Areas where coated Nomex felt FRSI is used; design envelope, not a material test limit"
      },
      "method": "Application limit printed in the AZoM article",
      "status": "ground",
      "source": "azom",
      "where": "Section on Coated Nomex Felt Reusable Surface Insulation, temperatures below 371°C",
      "source_detail": {
        "title": "Materials Used in Space Shuttle Thermal Protection Systems (AZoM, Alessandro Pirolini)",
        "url": "https://www.azom.com/article.aspx?ArticleID=11443",
        "year": 2020,
        "kind": "web",
        "license": "AZoM terms (cited, not reproduced)"
      }
    },
    {
      "benchmark": "design_temperature_range",
      "label": "Temperature band protected by FRSI blankets (KSC fact sheet)",
      "value": 350,
      "value_high": 700,
      "bound": "range",
      "unit": "°F",
      "scope": "material",
      "conditions": {
        "context": "Orbiter surfaces protected by FRSI blankets; design band"
      },
      "method": "Range printed in the NASA KSC Orbiter Thermal Protection System fact sheet",
      "status": "ground",
      "source": "ksc-tps",
      "where": "Felt Reusable Surface Insulation paragraph",
      "source_detail": {
        "title": "Orbiter Thermal Protection System, KSC fact sheet (archived copy, 2006 snapshot)",
        "url": "https://web.archive.org/web/20060909094330/http://www-pao.ksc.nasa.gov/kscpao/nasafact/tps.htm",
        "year": 2006,
        "kind": "report",
        "license": "Public domain (NASA)"
      }
    },
    {
      "benchmark": "max_service_temp",
      "label": "RTV silicone adhesive that bonds FRSI, upper temperature with bond strength kept (adhesive, not the felt)",
      "value": 550,
      "bound": "upper",
      "unit": "°F",
      "scope": "material",
      "conditions": {
        "material": "RTV silicone cement that bonds the tiles and blankets",
        "condition": "Bond strength retained"
      },
      "method": "Printed in the NASA KSC fact sheet",
      "status": "ground",
      "source": "ksc-tps",
      "where": "Paragraph on the RTV adhesive",
      "source_detail": {
        "title": "Orbiter Thermal Protection System, KSC fact sheet (archived copy, 2006 snapshot)",
        "url": "https://web.archive.org/web/20060909094330/http://www-pao.ksc.nasa.gov/kscpao/nasafact/tps.htm",
        "year": 2006,
        "kind": "report",
        "license": "Public domain (NASA)"
      }
    },
    {
      "benchmark": "waterproofing_burnout_temp",
      "label": "Waterproofing burn-out temperature for the orbiter thermal protection",
      "value": 1100,
      "bound": "exact",
      "unit": "°F",
      "scope": "material",
      "conditions": {
        "material": "Dimethylethoxysilane waterproofing applied after flights",
        "applies_to": "Orbiter thermal protection system, as stated by KSC"
      },
      "method": "Printed in the NASA KSC fact sheet",
      "status": "ground",
      "source": "ksc-tps",
      "where": "Paragraph on rewaterproofing after each flight",
      "source_detail": {
        "title": "Orbiter Thermal Protection System, KSC fact sheet (archived copy, 2006 snapshot)",
        "url": "https://web.archive.org/web/20060909094330/http://www-pao.ksc.nasa.gov/kscpao/nasafact/tps.htm",
        "year": 2006,
        "kind": "report",
        "license": "Public domain (NASA)"
      }
    },
    {
      "benchmark": "fibre_length",
      "label": "Nomex fibre length in the felt",
      "value": 3,
      "bound": "exact",
      "unit": "inch",
      "scope": "material",
      "conditions": {
        "material": "Nomex aramid fibres used for the felt",
        "form": "Fibre before carding"
      },
      "method": "Printed in the NASA Gordon appendix A.4",
      "status": "ground",
      "source": "gordon",
      "where": "A.4, second paragraph",
      "source_detail": {
        "title": "Shuttle thermal protection system, Appendix A (NASA KSC public appendix, archived copy)",
        "url": "https://web.archive.org/web/20160307090308/http://science.ksc.nasa.gov/shuttle/nexgen/Nexgen_Downloads/Shuttle_Gordon_TPS-PUBLIC_Appendix.pdf",
        "kind": "report",
        "license": "Public domain (NASA)"
      }
    },
    {
      "benchmark": "fibre_fineness",
      "label": "Nomex fibre fineness in the felt",
      "value": 2,
      "bound": "exact",
      "unit": "denier",
      "scope": "material",
      "conditions": {
        "material": "Nomex aramid fibres used for the felt",
        "form": "Fibre before carding"
      },
      "method": "Printed in the NASA Gordon appendix A.4",
      "status": "ground",
      "source": "gordon",
      "where": "A.4, second paragraph",
      "source_detail": {
        "title": "Shuttle thermal protection system, Appendix A (NASA KSC public appendix, archived copy)",
        "url": "https://web.archive.org/web/20160307090308/http://science.ksc.nasa.gov/shuttle/nexgen/Nexgen_Downloads/Shuttle_Gordon_TPS-PUBLIC_Appendix.pdf",
        "kind": "report",
        "license": "Public domain (NASA)"
      }
    },
    {
      "benchmark": "bondline_thickness",
      "label": "RTV silicone adhesive bondline under FRSI",
      "value": 0.2,
      "bound": "exact",
      "unit": "inch",
      "scope": "material",
      "conditions": {
        "adhesive": "RTV silicon adhesive",
        "installation": "Bonds FRSI directly to the orbiter"
      },
      "method": "Printed in NASA KSC shuttle systems text",
      "status": "ground",
      "source": "ksc-sts-sys",
      "where": "Section on Felt Reusable Surface Insulation",
      "source_detail": {
        "title": "Space Shuttle systems, KSC shuttle technology page (archived copy, 2009 snapshot)",
        "url": "https://web.archive.org/web/20090715235829/http://science.ksc.nasa.gov/shuttle/technology/sts-newsref/sts_sys.html",
        "year": 2009,
        "kind": "report",
        "license": "Public domain (NASA)"
      }
    }
  ],
  "corrosion": [
    {
      "environment": "Water and humidity between flights (NASA Gordon appendix)",
      "headline": "The Gordon appendix says FRSI does not need rewaterproofing after each flight.",
      "effect": "The appendix says the Nomex polymer is hygrophobic by nature and the silicone elastomer coating inhibits water intrusion into the felt, so FRSI does not require post-flight rewaterproofing.",
      "rating": "low",
      "conditions": {
        "basis": "Statement about the installed FRSI blanket"
      },
      "source": "gordon",
      "where": "A.4 Felt Reusable Surface Insulation, first paragraph"
    },
    {
      "environment": "Water and humidity between flights (KSC fact sheet)",
      "headline": "The KSC fact sheet says the orbiter thermal protection is rewaterproofed after each flight.",
      "effect": "KSC says the waterproofing material burns out at 1,100 °F, which would expose the outer surface to water absorption, so the thermal protection is rewaterproofed after each flight. The sources disagree on whether FRSI needs this step.",
      "rating": "low",
      "conditions": {
        "basis": "General statement for the orbiter thermal protection, which KSC lists with FRSI"
      },
      "source": "ksc-tps",
      "where": "Paragraph on rewaterproofing after each flight"
    },
    {
      "environment": "Heat during processing and service",
      "headline": "The felt is heat treated to reduce shrinkage at high temperature.",
      "effect": "For FRSI, the Nomex felt is heat treated at 700°F for 30 minutes and then at 750°F for 30 minutes to reduce linear shrinkage at elevated temperatures; the felt darkens to a caramel colour. The appendix gives no degradation rate for the coated blanket.",
      "rating": "unknown",
      "conditions": {
        "process": "Heat treatment before coating"
      },
      "source": "gordon",
      "where": "A.4, third paragraph"
    }
  ],
  "risks": {
    "hazards": [
      {
        "text": "The DuPont page describes Nomex as an inherently flame-resistant, high-temperature fibre that does not melt, drip or support combustion in air. No safety data sheet or GHS record for the coated FRSI product was read in this run.",
        "ghs": [],
        "source": "dupont-nomex",
        "where": "Page text describing Nomex"
      },
      {
        "text": "Wikipedia calls Nomex an inherently flame-resistant fabric and a trademarked term. This describes the fibre family, not a hazard test of the coated FRSI blanket.",
        "ghs": [],
        "source": "wiki-nomex",
        "where": "Lead paragraph"
      }
    ],
    "failure_risks": [
      {
        "mode": "Water absorption if the waterproofing has burned out",
        "trigger": "Heating to the orbiter waterproofing burn-out temperature",
        "consequence": "KSC says the waterproofing burns out at 1,100 °F, exposing the outer surface to water absorption until it is rewaterproofed after the flight.",
        "severity": "moderate",
        "source": "ksc-tps",
        "where": "Paragraph on rewaterproofing after each flight"
      },
      {
        "mode": "Temperatures above the FRSI design envelope",
        "trigger": "Surface heating above 700 °F (NASA shuttle systems text) or 750 °F (Gordon appendix)",
        "consequence": "The NASA sources place FRSI only where temperatures stay below these limits. In hotter areas the orbiter used rigid tiles or other insulation. None of the sources gives a failure test result for FRSI above these limits.",
        "severity": "high",
        "source": "ksc-sts-sys",
        "where": "Numbered item 6, White blankets of coated Nomex felt"
      }
    ],
    "side_effects": [],
    "handling": [
      {
        "text": "Bond FRSI with RTV silicone adhesive applied at 0.2 inch thickness, as the NASA shuttle systems text describes.",
        "source": "ksc-sts-sys",
        "where": "Section on Felt Reusable Surface Insulation"
      },
      {
        "text": "Trim FRSI to a cavity template and paint-seal the exposed edges with white silicone elastomer, as the NASA appendix describes.",
        "source": "gordon",
        "where": "A.4, third paragraph (installation)"
      },
      {
        "text": "Keep FRSI areas within their design envelope: 700 °F in the NASA shuttle systems text, 750 °F in the Gordon appendix.",
        "source": "ksc-sts-sys",
        "where": "Numbered item 6, White blankets of coated Nomex felt"
      }
    ],
    "mitigations": []
  },
  "uses": [
    {
      "application": "heat-shields",
      "device": "Upper payload bay doors and upper wing surface of the Space Shuttle orbiter",
      "example": "KSC says FRSI blankets are now used only on the upper section of the payload bay doors and the inboard sections of the wing upper surface.",
      "source": "ksc-tps",
      "where": "Felt Reusable Surface Insulation paragraph"
    },
    {
      "application": "heat-shields",
      "device": "Thermal blankets on the orbiter payload bay doors, fuselage and upper wing surfaces",
      "example": "The Wikipedia Nomex article says Nomex was used as thermal blankets on the payload bay doors, fuselage and upper wing surfaces of the Space Shuttle Orbiter.",
      "source": "wiki-nomex",
      "where": "Section on the US space program"
    }
  ],
  "supply": [
    {
      "subject": "Nomex (meta-aramid polymer) used for the felt",
      "abundance": "A synthetic polymer, not a mined material. Wikipedia says Nomex is produced by condensation of m-phenylenediamine and isophthaloyl chloride.",
      "producers": [],
      "critical_lists": [],
      "substitutes": [],
      "source": "wiki-nomex",
      "where": "Chemistry paragraph"
    },
    {
      "subject": "Nomex felt supplier for the Shuttle FRSI (historic)",
      "abundance": "No current producer share found. NASA KSC lists Albany International Research Co., Dedham, Mass., as the Nomex felt contractor for the Shuttle thermal protection system.",
      "producers": [],
      "critical_lists": [],
      "substitutes": [],
      "source": "ksc-sts-sys",
      "where": "Contractors list at the end of the shuttle systems page"
    }
  ],
  "media": [],
  "documents": [
    {
      "title": "NASA Ames TPSX database entry: FRSI Blanket (Nomex Felt)",
      "type": "database",
      "url": "https://tpsx.arc.nasa.gov/Material?id=18"
    },
    {
      "title": "Shuttle thermal protection system, Appendix A (NASA KSC public appendix, archived copy)",
      "type": "report",
      "url": "https://web.archive.org/web/20160307090308/http://science.ksc.nasa.gov/shuttle/nexgen/Nexgen_Downloads/Shuttle_Gordon_TPS-PUBLIC_Appendix.pdf"
    },
    {
      "title": "Space Shuttle systems, KSC shuttle technology page (archived copy)",
      "type": "report",
      "url": "https://web.archive.org/web/20090715235829/http://science.ksc.nasa.gov/shuttle/technology/sts-newsref/sts_sys.html"
    },
    {
      "title": "Orbiter Thermal Protection System, KSC fact sheet (archived copy)",
      "type": "report",
      "url": "https://web.archive.org/web/20060909094330/http://www-pao.ksc.nasa.gov/kscpao/nasafact/tps.htm"
    },
    {
      "title": "DuPont Nomex 40th Anniversary page (archived copy)",
      "type": "datasheet",
      "url": "https://web.archive.org/web/20120217011922/http://www2.dupont.com/Nomex/en_US/news_events/40th_anniv.html"
    }
  ],
  "gaps": [
    "Density, thermal conductivity, specific heat and the multiple-use and single-use temperature limits are printed in the NASA TPSX entry only in exponent form (for example 8.65e+01 kg/m^3); they are left out under the no-exponent rule.",
    "No plain-number FRSI density, areal mass, tensile strength or tear strength was found in the sources read.",
    "The NASA TPSX reference list (Kourtides, NASA TM-103925; Rasky 1995; the Rockwell design data book) has no URLs, and those reports were not opened.",
    "No vacuum, thermal-cycling, outgassing or flight-derived test result for coated FRSI felt was found in the sources read.",
    "No safety data sheet or GHS record for the coated product was read; hazard entries rest on NASA and DuPont text.",
    "Coverage of the upper surfaces differs between NASA sources: about 25 percent in the KSC fact sheet and nearly 50 percent in the KSC shuttle systems text. Neither figure is recorded as a property.",
    "Rewaterproofing after flights is stated for the orbiter thermal protection in the KSC fact sheet but not for FRSI; the Gordon appendix says FRSI does not need it.",
    "Upper temperature for FRSI areas is 700 °F in the KSC shuttle systems text and 371 °C in the AZoM article, and 750 °F in the Gordon appendix. The sources are recorded side by side, not averaged.",
    "No current producer or country share was found for Nomex felt. The only named felt contractor is Albany International Research Co., in a Shuttle-era NASA page.",
    "NASA TPSX prints Emissivity and the KSC shuttle systems text prints Emittance; both are stored under thermal_emittance.",
    "Thickness, coating, vent-hole and bondline values are NASA descriptions of the Shuttle installation, not manufacturer datasheet values.",
    "Property names not in the canonical list: thickness, coating_thickness, vent_hole_diameter, vent_hole_spacing, design_temperature_range, waterproofing_burnout_temp, fibre_length, fibre_fineness and bondline_thickness.",
    "The NASA STS-6 press kit linked from Wikipedia returned an HTML page instead of a PDF, so it was not read. Critical-mineral lists were not checked for an aramid polymer.",
    "The web search budget for this run ran out, so no further sources were searched for beyond the links in the sources already read."
  ],
  "story": {
    "why": "FRSI (felt reusable surface insulation) is a white, flexible blanket of heat-treated Nomex felt with a white silicone elastomer coating. NASA bonded it directly to the Space Shuttle orbiter skin with RTV silicone adhesive, and placed it on surfaces where temperatures stayed below about 700 °F. The NASA sources give few plain numbers for the blanket itself, so this profile records only the values printed in the fetched pages.",
    "uses": [
      {
        "where": "Space Shuttle orbiter upper surfaces",
        "line": "NASA KSC says FRSI blankets are now used only on the upper section of the payload bay doors and the inboard sections of the wing upper surface. Wikipedia's Nomex article says Nomex was used as thermal blankets on the payload bay doors, fuselage and upper wing surfaces of the orbiter."
      }
    ],
    "can_do": [
      {
        "label": "Emissivity",
        "line": "The NASA TPSX entry gives an emissivity of 0.8, with an uncertainty of 0.04 printed in the same row. A NASA shuttle systems page gives the same emittance of 0.8 for FRSI.",
        "benchmark": "thermal_emittance",
        "scope": "material"
      },
      {
        "label": "Solar absorptance",
        "line": "The NASA shuttle systems page gives a solar absorptance of 0.32, in the same sentence as the emittance of 0.8.",
        "benchmark": "solar_absorptance",
        "scope": "material"
      },
      {
        "label": "Use temperature",
        "line": "The NASA shuttle systems page says FRSI blankets protect areas where temperatures are below 700 F. The Gordon appendix says 750 °F, and the AZoM article gives 371 °C.",
        "scope": "material",
        "value": "Below 700 °F in one NASA source"
      },
      {
        "label": "Thickness",
        "line": "NASA gives the installed FRSI thickness as 0.16 to 0.4 inch, set by the heat load encountered during entry.",
        "scope": "material",
        "value": "0.16 to 0.4 inch"
      }
    ],
    "compare": "FRSI is a low-temperature blanket: NASA places its use below 700 °F, and it is the lower of the two NASA design limits. The NASA sources disagree on the upper limit, giving 700 °F in the KSC shuttle systems text and 750 °F in the Gordon appendix, with 371 °C in the AZoM article. The NASA TPSX entry is the only database record here that gives emissivity as a table value, and it prints density and conductivity only in exponent form, so this profile does not compare those.",
    "compare_rows": [
      {
        "label": "Emissivity",
        "benchmark": "thermal_emittance",
        "scope": "material"
      },
      {
        "label": "Solar absorptance",
        "benchmark": "solar_absorptance",
        "scope": "material"
      },
      {
        "label": "Upper use temperature",
        "benchmark": "max_service_temp",
        "scope": "material"
      }
    ],
    "handling": [
      "Keep FRSI areas within their design envelope: 700 °F in the NASA shuttle systems text, and 750 °F in the Gordon appendix.",
      "Bond with RTV silicone adhesive at 0.2 inch thickness, as the NASA shuttle systems text describes.",
      "Trim to a cavity template and paint-seal the exposed edges, as the Gordon appendix describes."
    ],
    "good_for": [
      "Surfaces below about 700 °F on a re-entry vehicle, the design use NASA describes for FRSI.",
      "Places where a white surface with an emissivity of 0.8 is wanted for thermal control, as the NASA sources describe the coating."
    ],
    "watch_out": [
      "The upper limits disagree between NASA sources: 700 °F in one, 750 °F in another, and 371 °C in the AZoM article.",
      "The sources disagree on whether FRSI needs rewaterproofing after each flight.",
      "Density, thermal conductivity and specific heat are printed only in exponent form, so no values are shown for them.",
      "The RTV adhesive that bonds FRSI is rated to 550 °F. The adhesive, not the felt, sets that bond limit."
    ],
    "verdict": "FRSI is a white Nomex felt blanket that NASA used on Shuttle upper surfaces. This profile can state its temperature envelope, optical values and installation dimensions from NASA pages only; its density and conductivity are left out until a plain-number source is read.",
    "recipe": {
      "line": "Nomex is a meta-aramid polymer made by condensation of m-phenylenediamine and isophthaloyl chloride, and it is sold as fibre, paper and felt. FRSI is heat-treated Nomex felt with a white silicone elastomer coating, vented by 0.035 inch holes on 6 inch centers.",
      "parts": [
        {
          "name": "m-Phenylenediamine",
          "role": "Monomer. Wikipedia names it as one of the two monomers that react to form Nomex.",
          "source": "wiki-nomex",
          "where": "Chemistry paragraph"
        },
        {
          "name": "Isophthaloyl chloride",
          "role": "Monomer. The second monomer that reacts with m-phenylenediamine to form Nomex.",
          "source": "wiki-nomex",
          "where": "Chemistry paragraph"
        },
        {
          "name": "Silicone elastomer coating",
          "role": "White outer layer that waterproofs the felt and gives the blanket its thermal and optical properties.",
          "source": "gordon",
          "where": "A.4 Felt Reusable Surface Insulation"
        }
      ]
    },
    "risk_groups": [
      {
        "title": "For people",
        "lead": "No safety data sheet or GHS record for the coated product was read in this run.",
        "points": [
          {
            "label": "Fibre family",
            "line": "DuPont describes Nomex as an inherently flame-resistant, high-temperature fibre that does not melt, drip or support combustion in air."
          },
          {
            "label": "Gap",
            "line": "The product itself has no hazard record in this profile yet."
          }
        ],
        "level": 0,
        "verdict": "No hazard data found"
      },
      {
        "title": "If the blanket overheats",
        "lead": "These are design limits from NASA sources, not test results.",
        "points": [
          {
            "label": "Envelope",
            "line": "NASA places FRSI only where temperatures stay below 700 °F in one source and below 750 °F in another."
          },
          {
            "label": "Waterproofing",
            "line": "KSC says the waterproofing burns out at 1,100 °F, which exposes the outer surface to water absorption."
          }
        ]
      },
      {
        "title": "Handling and installation",
        "points": [
          {
            "label": "Adhesive",
            "line": "The NASA shuttle systems text bonds FRSI with RTV silicone adhesive at 0.2 inch thickness."
          },
          {
            "label": "Edges",
            "line": "Trimmed to a cavity template and paint-sealed with white silicone elastomer, according to the Gordon appendix."
          }
        ]
      }
    ]
  },
  "updated": "2026-11-01",
  "review": {
    "status": "draft",
    "method": "assistant",
    "checked_values": 17,
    "unreachable": 0,
    "caveats": 2,
    "note": "Read by an AI assistant on 2026-11-01 from NASA, KSC, AZoM, Wikipedia and DuPont pages fetched in this run. Density, conductivity, specific heat and temperature limits in the NASA TPSX entry are printed only in exponent form and are left out."
  },
  "sources": {
    "tpsx": {
      "title": "NASA Ames Thermal Protection Materials database: FRSI Blanket (Nomex Felt)",
      "url": "https://tpsx.arc.nasa.gov/Material?id=18",
      "kind": "database",
      "license": "Public domain (NASA)"
    },
    "azom": {
      "title": "Materials Used in Space Shuttle Thermal Protection Systems (AZoM, Alessandro Pirolini)",
      "url": "https://www.azom.com/article.aspx?ArticleID=11443",
      "year": 2020,
      "kind": "web",
      "license": "AZoM terms (cited, not reproduced)"
    },
    "wiki-tps": {
      "title": "Space Shuttle thermal protection system (Wikipedia)",
      "url": "https://en.wikipedia.org/wiki/Space_Shuttle_thermal_protection_system",
      "kind": "web",
      "license": "CC BY-SA 4.0 (Wikipedia)"
    },
    "wiki-nomex": {
      "title": "Nomex (Wikipedia)",
      "url": "https://en.wikipedia.org/wiki/Nomex",
      "kind": "web",
      "license": "CC BY-SA 4.0 (Wikipedia)"
    },
    "ksc-tps": {
      "title": "Orbiter Thermal Protection System, KSC fact sheet (archived copy, 2006 snapshot)",
      "url": "https://web.archive.org/web/20060909094330/http://www-pao.ksc.nasa.gov/kscpao/nasafact/tps.htm",
      "year": 2006,
      "kind": "report",
      "license": "Public domain (NASA)"
    },
    "ksc-sts-sys": {
      "title": "Space Shuttle systems, KSC shuttle technology page (archived copy, 2009 snapshot)",
      "url": "https://web.archive.org/web/20090715235829/http://science.ksc.nasa.gov/shuttle/technology/sts-newsref/sts_sys.html",
      "year": 2009,
      "kind": "report",
      "license": "Public domain (NASA)"
    },
    "gordon": {
      "title": "Shuttle thermal protection system, Appendix A (NASA KSC public appendix, archived copy)",
      "url": "https://web.archive.org/web/20160307090308/http://science.ksc.nasa.gov/shuttle/nexgen/Nexgen_Downloads/Shuttle_Gordon_TPS-PUBLIC_Appendix.pdf",
      "kind": "report",
      "license": "Public domain (NASA)"
    },
    "dupont-nomex": {
      "title": "DuPont Nomex 40th Anniversary page (archived copy, 2012 snapshot)",
      "url": "https://web.archive.org/web/20120217011922/http://www2.dupont.com/Nomex/en_US/news_events/40th_anniv.html",
      "year": 2007,
      "kind": "web",
      "license": "DuPont terms (cited, not reproduced)"
    }
  },
  "license": "CC-BY-4.0",
  "url": "https://spacemushroom.com/profiles/frsi-nomex-felt-blanket/"
}