{
  "spore": "profile",
  "id": "beta-cloth",
  "spore_version": "0.2",
  "family": "glass-textiles",
  "name": "Beta cloth",
  "role": "PTFE-coated woven glass fabric for spacesuit outer layers and spacecraft covers",
  "category": "textiles",
  "type": "beta-cloth",
  "summary": "Beta cloth is a woven textile made from Beta fibre, an extra-fine glass filament that Owens-Corning made under NASA contract. The filaments are nominally 3.8 microns in diameter (Dillon and Cobb, 1975). The woven fabric was coated with Teflon (PTFE). The Teflon-coated style X4190B weighed 6.6 oz/sq yd at coating level 1 and 7.8 oz/sq yd at coating level 2 (Dillon and Cobb, 1975). The fabric was noncombustible in a 100 percent oxygen atmosphere up to 16.5 psia (Dillon and Cobb, 1975), which is why it was used in the Apollo capsule and on the Apollo spacesuit outer layer. After Apollo, inspection found the fabric badly abraded by lunar dust.\n",
  "best_for": "Noncombustible, flexible glass textile for oxygen-rich spacecraft and spacesuit layers where abrasion from the surface is not the main load",
  "weakest_at": "Abrasion. Post-Apollo inspection found Beta cloth frayed and broken by lunar dust, and the fabric failed NASA's rotary tumbler abrasion test (ICES 2025).",
  "identity": {
    "formula": "Woven fine-filament glass fabric coated with PTFE (Teflon); the coating repeat unit is (CF2-CF2)n",
    "designations": [
      {
        "system": "Trade name",
        "code": "Beta Fiberglass",
        "source": "fire-fibers-2017",
        "where": "Development of Beta Fiber, first paragraph (trade mark of Owens-Corning Fiberglas Corporation, per the 1975 paper)"
      },
      {
        "system": "Trade name",
        "code": "X4190B",
        "note": "Owens-Corning style number for the Teflon-coated Beta fabric; the style number is not a trade name",
        "source": "dillon-cobb-1975",
        "where": "Appendix A, title of Teflon-coated Beta fabric table"
      },
      {
        "system": "Trade name",
        "code": "X4484",
        "note": "Owens-Corning style number for a second Teflon-coated Beta fabric, woven from Teflon-coated yarn",
        "source": "dillon-cobb-1975",
        "where": "Appendix A, title of X4484 Fabric/Teflon-Coated Yarn table"
      }
    ],
    "source": "dillon-cobb-1975",
    "where": "Abstract and Introduction (Beta fibre, Teflon coating); Appendix A table title for X4190B Teflon-coated Beta fabric. Repeat unit from Wikipedia, Polytetrafluoroethylene, Production section"
  },
  "tags": {
    "environments": [
      "lunar-day",
      "low-earth-orbit"
    ],
    "stresses": [
      "atomic-oxygen"
    ],
    "applications": [
      "habitats-and-suits",
      "thermal-control",
      "structures"
    ]
  },
  "properties": [
    {
      "benchmark": "max_service_temp",
      "label": "Maximum service temperature, Beta fibre fabric",
      "value": 482,
      "bound": "exact",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "form": "Beta fibre textile (Owens-Corning Beta Fiberglass)",
        "basis": "range printed as -300 °F to 900 °F (-184 °C and 482 °C)"
      },
      "method": "Value stated in a NASA technical paper, read from the printed text",
      "status": "ground",
      "source": "fire-fibers-2017",
      "where": "Development of Beta Fiber, first paragraph (quotation of Orndoff, 2016)",
      "source_detail": {
        "title": "Flame Retardant Fibers for Human Space Exploration - Past, Present, and Future",
        "id": "NTRS 20170008542",
        "url": "https://ntrs.nasa.gov/citations/20170008542",
        "year": 2017,
        "kind": "report",
        "license": "public domain (NASA)"
      }
    },
    {
      "benchmark": "min_service_temp",
      "label": "Minimum service temperature, Beta fibre fabric",
      "value": -184,
      "bound": "exact",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "form": "Beta fibre textile (Owens-Corning Beta Fiberglass)",
        "basis": "range printed as -300 °F to 900 °F (-184 °C and 482 °C)"
      },
      "method": "Value stated in a NASA technical paper, read from the printed text",
      "status": "ground",
      "source": "fire-fibers-2017",
      "where": "Development of Beta Fiber, first paragraph (quotation of Orndoff, 2016)",
      "source_detail": {
        "title": "Flame Retardant Fibers for Human Space Exploration - Past, Present, and Future",
        "id": "NTRS 20170008542",
        "url": "https://ntrs.nasa.gov/citations/20170008542",
        "year": 2017,
        "kind": "report",
        "license": "public domain (NASA)"
      }
    },
    {
      "benchmark": "degradation_temperature",
      "label": "Degradation temperature, Beta fibre",
      "value": 843,
      "bound": "exact",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "form": "Beta fibre",
        "basis": "printed as degraded at 1550 °F (843 °C)"
      },
      "method": "Value stated in a NASA technical paper, read from the printed text",
      "status": "ground",
      "source": "fire-fibers-2017",
      "where": "Development of Beta Fiber, first paragraph (quotation of Orndoff, 2016)",
      "source_detail": {
        "title": "Flame Retardant Fibers for Human Space Exploration - Past, Present, and Future",
        "id": "NTRS 20170008542",
        "url": "https://ntrs.nasa.gov/citations/20170008542",
        "year": 2017,
        "kind": "report",
        "license": "public domain (NASA)"
      }
    },
    {
      "benchmark": "filament_diameter",
      "label": "Filament diameter, Beta fibre (range)",
      "value": 3.5,
      "value_high": 3.8,
      "bound": "range",
      "unit": "µm",
      "scope": "material",
      "conditions": {
        "form": "extra-fine Beta glass filament",
        "basis": "printed as 3.5 to 3.8 microns"
      },
      "method": "Value stated in a NASA technical paper, read from the printed text",
      "status": "ground",
      "source": "fire-fibers-2017",
      "where": "Development of Beta Fiber, first paragraph (quotation of Orndoff, 2016)",
      "source_detail": {
        "title": "Flame Retardant Fibers for Human Space Exploration - Past, Present, and Future",
        "id": "NTRS 20170008542",
        "url": "https://ntrs.nasa.gov/citations/20170008542",
        "year": 2017,
        "kind": "report",
        "license": "public domain (NASA)"
      }
    },
    {
      "benchmark": "filament_diameter",
      "label": "Filament diameter, Beta fibre (nominal)",
      "value": 3.8,
      "bound": "exact",
      "unit": "µm",
      "scope": "material",
      "conditions": {
        "form": "Beta filament, nominal",
        "basis": "printed as nominally 3.8 microns, or 1/4 denier"
      },
      "method": "Value stated in the 1975 Owens-Corning report, read from the scanned text layer",
      "status": "ground",
      "note": "The same report gives the denier as 1/4; the value is read from the scanned text layer and not from the image.",
      "source": "dillon-cobb-1975",
      "where": "Introduction, paragraph on Beta filament diameter",
      "source_detail": {
        "title": "Research, development and application of noncombustible Beta fiber structures",
        "id": "NTRS 19750021113 (J. J. Dillon and E. S. Cobb, Owens-Corning Fiberglas Corp., 1975)",
        "url": "https://ntrs.nasa.gov/citations/19750021113",
        "year": 1975,
        "kind": "report",
        "license": "public domain (NASA)"
      }
    },
    {
      "benchmark": "noncombustible_pressure_in_oxygen",
      "label": "Noncombustible limit in 100 percent oxygen, Beta fibre",
      "value": 16.5,
      "bound": "exact",
      "unit": "psia",
      "scope": "material",
      "conditions": {
        "atmosphere": "100 percent oxygen",
        "result": "noncombustible up to this pressure (Apollo capsule environment), as printed"
      },
      "method": "Value stated in the abstract of the 1975 report",
      "status": "ground",
      "source": "dillon-cobb-1975",
      "where": "Abstract; Introduction (basic requirements paragraph)",
      "source_detail": {
        "title": "Research, development and application of noncombustible Beta fiber structures",
        "id": "NTRS 19750021113 (J. J. Dillon and E. S. Cobb, Owens-Corning Fiberglas Corp., 1975)",
        "url": "https://ntrs.nasa.gov/citations/19750021113",
        "year": 1975,
        "kind": "report",
        "license": "public domain (NASA)"
      }
    },
    {
      "benchmark": "fabric_weight",
      "label": "Fabric weight, X4190B Teflon-coated Beta fabric (range over two coating levels)",
      "value": 6.6,
      "value_high": 7.8,
      "bound": "range",
      "unit": "oz/sq yd",
      "scope": "material",
      "conditions": {
        "style": "X4190B Teflon-coated Beta fabric",
        "coating_levels": "level 1 gives 6.6 and level 2 gives 7.8, as printed",
        "test_method": "ASTM D579 as printed"
      },
      "method": "Typical value printed in the Appendix A table of the 1975 report",
      "status": "ground",
      "source": "dillon-cobb-1975",
      "where": "Appendix A table, Typical Physical Properties of X4190B Teflon-Coated Beta Fabric at Two Coating Levels, Fabric Weight row (printed page 13)",
      "source_detail": {
        "title": "Research, development and application of noncombustible Beta fiber structures",
        "id": "NTRS 19750021113 (J. J. Dillon and E. S. Cobb, Owens-Corning Fiberglas Corp., 1975)",
        "url": "https://ntrs.nasa.gov/citations/19750021113",
        "year": 1975,
        "kind": "report",
        "license": "public domain (NASA)"
      }
    },
    {
      "benchmark": "yarn_count",
      "label": "Yarn count, X4190B warp",
      "value": 92,
      "bound": "exact",
      "unit": "yarns/in",
      "scope": "material",
      "conditions": {
        "style": "X4190B Teflon-coated Beta fabric",
        "direction": "warp, at both coating levels",
        "test_method": "ASTM D579 as printed"
      },
      "method": "Typical value printed in the Appendix A table of the 1975 report",
      "status": "ground",
      "source": "dillon-cobb-1975",
      "where": "Appendix A table, Yarn Count row (printed page 13)",
      "source_detail": {
        "title": "Research, development and application of noncombustible Beta fiber structures",
        "id": "NTRS 19750021113 (J. J. Dillon and E. S. Cobb, Owens-Corning Fiberglas Corp., 1975)",
        "url": "https://ntrs.nasa.gov/citations/19750021113",
        "year": 1975,
        "kind": "report",
        "license": "public domain (NASA)"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "label": "Breaking strength, X4190B warp (range over two coating levels)",
      "value": 90,
      "value_high": 115,
      "bound": "range",
      "unit": "lbs/in",
      "scope": "material",
      "conditions": {
        "style": "X4190B Teflon-coated Beta fabric",
        "direction": "warp, original (not roller-creased)",
        "coating_levels": "level 2 gives 90 and level 1 gives 115, as printed",
        "test_method": "ASTM D1682, Instron at 0.6 in/min as printed"
      },
      "method": "Typical value printed in the Appendix A table of the 1975 report; printed in lbs/in and not converted here",
      "status": "ground",
      "note": "Read from a scanned table and checked visually. The fill value at level 1 is not legible in the scan and is left out.",
      "source": "dillon-cobb-1975",
      "where": "Appendix A table, Break Strength (Instron 0.6 IPM), Original row (printed page 13)",
      "source_detail": {
        "title": "Research, development and application of noncombustible Beta fiber structures",
        "id": "NTRS 19750021113 (J. J. Dillon and E. S. Cobb, Owens-Corning Fiberglas Corp., 1975)",
        "url": "https://ntrs.nasa.gov/citations/19750021113",
        "year": 1975,
        "kind": "report",
        "license": "public domain (NASA)"
      }
    },
    {
      "benchmark": "tongue_tear",
      "label": "Tongue tear, X4190B warp at coating level 1",
      "value": 4.5,
      "bound": "exact",
      "unit": "lbs",
      "scope": "material",
      "conditions": {
        "style": "X4190B Teflon-coated Beta fabric",
        "direction": "warp, coating level 1",
        "test_method": "ASTM D2262 as printed"
      },
      "method": "Typical value printed in the Appendix A table of the 1975 report",
      "status": "ground",
      "source": "dillon-cobb-1975",
      "where": "Appendix A table, Tongue Tear row (printed page 13)",
      "source_detail": {
        "title": "Research, development and application of noncombustible Beta fiber structures",
        "id": "NTRS 19750021113 (J. J. Dillon and E. S. Cobb, Owens-Corning Fiberglas Corp., 1975)",
        "url": "https://ntrs.nasa.gov/citations/19750021113",
        "year": 1975,
        "kind": "report",
        "license": "public domain (NASA)"
      }
    },
    {
      "benchmark": "stoll_flat_abrasion",
      "label": "Stoll flat abrasion, X4190B warp (range over two coating levels)",
      "value": 282,
      "value_high": 738,
      "bound": "range",
      "unit": "cycles",
      "scope": "material",
      "conditions": {
        "style": "X4190B Teflon-coated Beta fabric",
        "direction": "warp, 1 lb load and 3 lb pressure, as printed",
        "coating_levels": "level 1 gives 282 and level 2 gives 738"
      },
      "method": "Typical value printed in the Appendix A table of the 1975 report; test method ASTM D1175-64T-A as printed",
      "status": "ground",
      "source": "dillon-cobb-1975",
      "where": "Appendix A table, Stoll Abrasion Flat row (printed page 13)",
      "source_detail": {
        "title": "Research, development and application of noncombustible Beta fiber structures",
        "id": "NTRS 19750021113 (J. J. Dillon and E. S. Cobb, Owens-Corning Fiberglas Corp., 1975)",
        "url": "https://ntrs.nasa.gov/citations/19750021113",
        "year": 1975,
        "kind": "report",
        "license": "public domain (NASA)"
      }
    },
    {
      "benchmark": "taber_abrasion_to_fabric_failure",
      "label": "Taber abrasion to fabric failure, X4190B warp at coating level 1",
      "value": 351,
      "bound": "exact",
      "unit": "cycles",
      "scope": "material",
      "conditions": {
        "style": "X4190B Teflon-coated Beta fabric",
        "direction": "warp, coating level 1",
        "load": "500 g on CS 17 wheel, as printed"
      },
      "method": "Typical value printed in the Appendix A table of the 1975 report",
      "status": "ground",
      "source": "dillon-cobb-1975",
      "where": "Appendix A table, Taber Abrasion, Fabric Failure row (printed page 13)",
      "source_detail": {
        "title": "Research, development and application of noncombustible Beta fiber structures",
        "id": "NTRS 19750021113 (J. J. Dillon and E. S. Cobb, Owens-Corning Fiberglas Corp., 1975)",
        "url": "https://ntrs.nasa.gov/citations/19750021113",
        "year": 1975,
        "kind": "report",
        "license": "public domain (NASA)"
      }
    },
    {
      "benchmark": "air_permeability",
      "label": "Air permeability, X4190B warp (range over two coating levels)",
      "value": 3.94,
      "value_high": 30.7,
      "bound": "range",
      "unit": "cu ft/min/sq ft",
      "scope": "material",
      "conditions": {
        "style": "X4190B Teflon-coated Beta fabric",
        "direction": "warp, 20 in water pressure drop, as printed",
        "coating_levels": "level 2 gives 3.94 and level 1 gives 30.7"
      },
      "method": "Typical value printed in the Appendix A table of the 1975 report; test method ASTM D737 as printed",
      "status": "ground",
      "source": "dillon-cobb-1975",
      "where": "Appendix A table, Air Permeability row (printed page 13)",
      "source_detail": {
        "title": "Research, development and application of noncombustible Beta fiber structures",
        "id": "NTRS 19750021113 (J. J. Dillon and E. S. Cobb, Owens-Corning Fiberglas Corp., 1975)",
        "url": "https://ntrs.nasa.gov/citations/19750021113",
        "year": 1975,
        "kind": "report",
        "license": "public domain (NASA)"
      }
    },
    {
      "benchmark": "seam_strength",
      "label": "Seam strength, X4190B warp at coating level 1",
      "value": 14.4,
      "bound": "exact",
      "unit": "lbs",
      "scope": "material",
      "conditions": {
        "style": "X4190B Teflon-coated Beta fabric",
        "direction": "warp, coating level 1",
        "test_method": "ASTM D434 as printed"
      },
      "method": "Typical value printed in the Appendix A table of the 1975 report",
      "status": "ground",
      "source": "dillon-cobb-1975",
      "where": "Appendix A table, Seam Strength row (printed page 13)",
      "source_detail": {
        "title": "Research, development and application of noncombustible Beta fiber structures",
        "id": "NTRS 19750021113 (J. J. Dillon and E. S. Cobb, Owens-Corning Fiberglas Corp., 1975)",
        "url": "https://ntrs.nasa.gov/citations/19750021113",
        "year": 1975,
        "kind": "report",
        "license": "public domain (NASA)"
      }
    },
    {
      "benchmark": "ignition_loss",
      "label": "Ignition loss, X4190B warp (range over two coating levels)",
      "value": 12.2,
      "value_high": 20.4,
      "bound": "range",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "style": "X4190B Teflon-coated Beta fabric",
        "direction": "warp, coating levels 1 and 2 as printed",
        "test_method": "OCF-DF510 as printed"
      },
      "method": "Typical value printed in the Appendix A table of the 1975 report; the report does not define the term beyond the test method name",
      "status": "ground",
      "source": "dillon-cobb-1975",
      "where": "Appendix A table, Ignition Loss row (printed page 13)",
      "source_detail": {
        "title": "Research, development and application of noncombustible Beta fiber structures",
        "id": "NTRS 19750021113 (J. J. Dillon and E. S. Cobb, Owens-Corning Fiberglas Corp., 1975)",
        "url": "https://ntrs.nasa.gov/citations/19750021113",
        "year": 1975,
        "kind": "report",
        "license": "public domain (NASA)"
      }
    },
    {
      "benchmark": "fabric_weight",
      "label": "Fabric weight, X4484 Teflon-coated yarn fabric (warp)",
      "value": 6.18,
      "bound": "exact",
      "unit": "oz/sq yd",
      "scope": "material",
      "conditions": {
        "style": "X4484 fabric woven from B 150 1/0 Teflon-coated sintered yarn",
        "direction": "warp",
        "test_method": "ASTM D579 as printed"
      },
      "method": "Typical value printed in the Appendix A table of the 1975 report (two tests)",
      "status": "ground",
      "source": "dillon-cobb-1975",
      "where": "Appendix A table, Typical Physical Properties of X4484 Fabric/Teflon-Coated Yarn, Fabric Weight row (printed page 15)",
      "source_detail": {
        "title": "Research, development and application of noncombustible Beta fiber structures",
        "id": "NTRS 19750021113 (J. J. Dillon and E. S. Cobb, Owens-Corning Fiberglas Corp., 1975)",
        "url": "https://ntrs.nasa.gov/citations/19750021113",
        "year": 1975,
        "kind": "report",
        "license": "public domain (NASA)"
      }
    },
    {
      "benchmark": "thickness",
      "label": "Thickness, X4484 fabric (warp)",
      "value": 7.6,
      "bound": "exact",
      "unit": "mils",
      "scope": "material",
      "conditions": {
        "style": "X4484 fabric woven from B 150 1/0 Teflon-coated sintered yarn",
        "direction": "warp",
        "test_method": "CCC-T-191B-5030 as printed"
      },
      "method": "Typical value printed in the Appendix A table of the 1975 report (five tests)",
      "status": "ground",
      "source": "dillon-cobb-1975",
      "where": "Appendix A table, Thickness row (printed page 15)",
      "source_detail": {
        "title": "Research, development and application of noncombustible Beta fiber structures",
        "id": "NTRS 19750021113 (J. J. Dillon and E. S. Cobb, Owens-Corning Fiberglas Corp., 1975)",
        "url": "https://ntrs.nasa.gov/citations/19750021113",
        "year": 1975,
        "kind": "report",
        "license": "public domain (NASA)"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "label": "Breaking strength, X4484 fabric (warp, original)",
      "value": 208,
      "bound": "exact",
      "unit": "lbs/inch",
      "scope": "material",
      "conditions": {
        "style": "X4484 fabric woven from B 150 1/0 Teflon-coated sintered yarn",
        "direction": "warp, original (not roller-creased)",
        "test_method": "ASTM D1682-1C-E as printed"
      },
      "method": "Typical value printed in the Appendix A table of the 1975 report; printed in lbs/inch and not converted here",
      "status": "ground",
      "source": "dillon-cobb-1975",
      "where": "Appendix A table, Breaking Strength Original row, warp column (printed page 15)",
      "source_detail": {
        "title": "Research, development and application of noncombustible Beta fiber structures",
        "id": "NTRS 19750021113 (J. J. Dillon and E. S. Cobb, Owens-Corning Fiberglas Corp., 1975)",
        "url": "https://ntrs.nasa.gov/citations/19750021113",
        "year": 1975,
        "kind": "report",
        "license": "public domain (NASA)"
      }
    },
    {
      "benchmark": "mit_flex_cycles",
      "label": "MIT flex cycles, X4484 fabric (warp)",
      "value": 12708,
      "bound": "exact",
      "unit": "cycles",
      "scope": "material",
      "conditions": {
        "style": "X4484 fabric woven from B 150 1/0 Teflon-coated sintered yarn",
        "direction": "warp, 1.5 kg load, 0.59 in spec, 0.01 head, as printed",
        "note_as_printed": "fill direction printed as 18048 cycles"
      },
      "method": "Typical value printed in the Appendix A table of the 1975 report (five tests)",
      "status": "ground",
      "source": "dillon-cobb-1975",
      "where": "Appendix A table, MIT Flex row (printed page 15)",
      "source_detail": {
        "title": "Research, development and application of noncombustible Beta fiber structures",
        "id": "NTRS 19750021113 (J. J. Dillon and E. S. Cobb, Owens-Corning Fiberglas Corp., 1975)",
        "url": "https://ntrs.nasa.gov/citations/19750021113",
        "year": 1975,
        "kind": "report",
        "license": "public domain (NASA)"
      }
    },
    {
      "benchmark": "taber_abrasion_to_fabric_failure",
      "label": "Taber abrasion, X4484 fabric (warp)",
      "value": 972,
      "bound": "exact",
      "unit": "cycles",
      "scope": "material",
      "conditions": {
        "style": "X4484 fabric woven from B 150 1/0 Teflon-coated sintered yarn",
        "direction": "warp, 500 g on CS 17 wheel, as printed"
      },
      "method": "Typical value printed in the Appendix A table of the 1975 report (five tests)",
      "status": "ground",
      "source": "dillon-cobb-1975",
      "where": "Appendix A table, Taber Abrasion row (printed page 15)",
      "source_detail": {
        "title": "Research, development and application of noncombustible Beta fiber structures",
        "id": "NTRS 19750021113 (J. J. Dillon and E. S. Cobb, Owens-Corning Fiberglas Corp., 1975)",
        "url": "https://ntrs.nasa.gov/citations/19750021113",
        "year": 1975,
        "kind": "report",
        "license": "public domain (NASA)"
      }
    },
    {
      "benchmark": "mullen_burst",
      "label": "Mullen burst, X4484 fabric (warp)",
      "value": 482,
      "bound": "exact",
      "unit": "Mullen points",
      "scope": "material",
      "conditions": {
        "style": "X4484 fabric woven from B 150 1/0 Teflon-coated sintered yarn",
        "direction": "warp, test method OCF-DF511 as printed"
      },
      "method": "Typical value printed in the Appendix A table of the 1975 report (five tests)",
      "status": "ground",
      "source": "dillon-cobb-1975",
      "where": "Appendix A table, Mullen Burst row (printed page 15)",
      "source_detail": {
        "title": "Research, development and application of noncombustible Beta fiber structures",
        "id": "NTRS 19750021113 (J. J. Dillon and E. S. Cobb, Owens-Corning Fiberglas Corp., 1975)",
        "url": "https://ntrs.nasa.gov/citations/19750021113",
        "year": 1975,
        "kind": "report",
        "license": "public domain (NASA)"
      }
    }
  ],
  "corrosion": [
    {
      "environment": "Atomic oxygen in low Earth orbit",
      "headline": "Tightly woven glass is stated to resist atomic oxygen, but the coated fabric was not tested for it.",
      "effect": "The 2025 ICES paper says that glass is inorganic and that, when woven tightly, glass fibres resist degradation from atomic oxygen in low Earth orbit. The 2017 NASA paper says glass and ceramic structures have excellent resistance to atomic oxygen, while atomic oxygen degrades organic materials over time. No atomic-oxygen test of the PTFE-coated fabric was found in the sources read.",
      "rating": "low",
      "conditions": {
        "basis": "general statements about woven glass fibres; no test data printed",
        "coating": "PTFE (Teflon), an organic polymer"
      },
      "source": "ices-2025-jones",
      "where": "Section B, Current State of the Art (Beta Cloth and Ortho Fabric)"
    },
    {
      "environment": "Lunar regolith and dust abrasion during Apollo EVA",
      "headline": "Apollo-era Beta cloth was severely degraded by lunar dust and abrasion after short use.",
      "effect": "Scanning electron microscopy of the outer soft layers of Apollo 12 and Apollo 17 thermal micrometeoroid garments, and of the outermost fabrics on Apollo 17 EVA gloves, found fibres frayed and broken, with lunar dust embedded in the weave. The authors say the suits did not fail during EVA, but the fabric was degraded severely for the length of use.",
      "rating": "severe",
      "conditions": {
        "basis": "post-flight inspection of Apollo hardware, as described in the paper",
        "exposure": "relatively short Apollo EVA durations"
      },
      "source": "ices-2025-jones",
      "where": "Section C, Need for Innovation"
    },
    {
      "environment": "NASA rotary tumbler abrasion test (laboratory)",
      "headline": "Beta cloth failed the NASA rotary tumbler abrasion test and was dropped from the trade study.",
      "effect": "The 2025 ICES trade study included Beta cloth as a benchmark, but it failed the NASA rotary tumbler abrasion test, which the authors say shows insufficient durability for sustained lunar use. The paper does not print test numbers for Beta cloth in this test.",
      "rating": "severe",
      "conditions": {
        "test": "NASA custom rotary tumbler abrasion test",
        "basis": "statement in the trade study section; no numbers printed for Beta cloth"
      },
      "source": "ices-2025-jones",
      "where": "Section on trade study results (Beta Cloth included as a benchmark, then excluded)"
    },
    {
      "environment": "Sewing, flexing and weaving of the fabric",
      "headline": "The fragile glass fibres crack when sewn and flexed, and weaving needed silicone oil.",
      "effect": "The 2025 ICES paper says the fabric was difficult to assemble into a garment because the fragile glass fibres tended to crack when sewn and flexed. Silicone oil had to be applied to keep the fibres together during weaving, and it made sewn seams pull out easily, so seam edges were coated with cement.",
      "rating": "moderate",
      "conditions": {
        "basis": "manufacturing experience described in the paper; no flex-cycle data printed for Beta cloth"
      },
      "source": "ices-2025-jones",
      "where": "Section C, Need for Innovation"
    }
  ],
  "risks": {
    "hazards": [
      {
        "text": "NIOSH's fibrous glass entry, which covers glass filaments and glass wool in general and is not an entry for Beta fibre, lists the symptoms as \"irritation eyes, skin, nose, throat; dyspnea (breathing difficulty)\". Its NIOSH REL is \"TWA 3 fibers/cm3 (fibers ≤ 3.5 µm in diameter & ≥ 10 µm in length) TWA 5 mg/m3 (total)\". Beta filaments are printed as 3.5 to 3.8 µm in diameter (Dillon and Cobb, 1975).",
        "ghs": [],
        "source": "niosh-npg-fibrous-glass",
        "where": "Synonyms and Trade Names, Physical Description, Exposure Limits (NIOSH REL) and Symptoms fields of the NIOSH Pocket Guide fibrous glass entry"
      },
      {
        "text": "Daikin's 2011 safety data sheet for POLYFLON PTFE M-532, a PTFE product and not the coated Beta fabric, states that the substance is not classified under the CLP regulation, with no hazard pictograms, signal word or hazard statements. It says that vapours and fumes from hot processing (\"above 260 ℃\") may cause flu-like symptoms, and that the material has a \"Danger of toxic fluorine based pyrolysis products\" when it decomposes.",
        "ghs": [],
        "source": "daikin-ptfe-sds",
        "where": "Section 2 (classification and labelling), Section 4 (information for doctor), Section 10 (hazardous decomposition products)"
      }
    ],
    "failure_risks": [
      {
        "mode": "Abrasion failure in lunar dust",
        "trigger": "Lunar regolith and dust rubbing the outer fabric during EVA",
        "consequence": "Fibres frayed and broken, with dust embedded in the weave; the fabric is not durable enough for a sustained lunar presence",
        "severity": "high",
        "source": "ices-2025-jones",
        "where": "Section C, Need for Innovation"
      },
      {
        "mode": "Fibre cracking in garment manufacture",
        "trigger": "Sewing or flexing the fragile glass filaments",
        "consequence": "Fibres crack, and seams need cement to hold",
        "severity": "moderate",
        "source": "ices-2025-jones",
        "where": "Section C, Need for Innovation"
      }
    ],
    "side_effects": [
      {
        "text": "Coating the woven surface with Teflon reduced the tear strength of the fabric; coating the individual yarns before weaving fixed this but was costly.",
        "affects": "Garment tear resistance",
        "source": "ices-2025-jones",
        "where": "Section C, Need for Innovation"
      }
    ],
    "handling": [
      {
        "text": "Chalk bags were used to mark patterns instead of pencils to avoid degrading the fabric during garment assembly.",
        "source": "ices-2025-jones",
        "where": "Section C, Need for Innovation"
      },
      {
        "text": "Silicone oil used in weaving makes sewn seams pull out easily, so seam edges were coated with cement.",
        "source": "ices-2025-jones",
        "where": "Section C, Need for Innovation"
      }
    ],
    "mitigations": [
      {
        "text": "Applying the Teflon coating to individual yarns before weaving avoided the tear-strength loss but added processing cost.",
        "source": "ices-2025-jones",
        "where": "Section C, Need for Innovation"
      }
    ]
  },
  "uses": [
    {
      "application": "habitats-and-suits",
      "device": "Apollo spacesuit outer layer and flight suits",
      "example": "Woven Beta fabrics were selected for the outer layer of Apollo space suits and flight suits, for the interior liner of the Apollo command module, and for several crew equipment items and fire protective covers. The paper credits Orndoff (2016) for this summary.",
      "source": "fire-fibers-2017",
      "where": "Development of Beta Fiber, first paragraph (quotation of Orndoff, 2016)"
    },
    {
      "application": "structures",
      "device": "Space Shuttle cargo bay contamination control cover",
      "example": "The largest use of Beta fabric in the Space Shuttle Program's Orbiter was the contamination control cover of the cargo bay. Between 1967 and 1990 approximately 10450 lb of Beta fabrics were used in the Apollo, Skylab, Apollo-Soyuz, Space Shuttle and Spacelab programs combined.",
      "source": "fire-fibers-2017",
      "where": "Development of Beta Fiber, first paragraph (quotation of Orndoff, 2016)"
    },
    {
      "application": "thermal-control",
      "device": "Spacer in aluminised Kapton superinsulation (ITMG)",
      "example": "Beta marquisette was used as a spacer material between aluminised Kapton layers in the ITMG superinsulation system.",
      "source": "dillon-cobb-1975",
      "where": "Section 2, Textile End-Item Development, list of end items"
    },
    {
      "application": "electronics-and-chips",
      "device": "Teflon-coated bags around electrical connectors and encapsulation of flammable flight items",
      "example": "Teflon-coated Beta fabrics were used for bags placed around electrical connectors and for encapsulating flammable flight items. In a tissue container, the fabric protected the facial tissues against flame impingement at 1800 °F in an oxygen atmosphere for 8 minutes without charring them.",
      "source": "dillon-cobb-1975",
      "where": "Section 1, paragraph on Teflon coatings (Dillon and Cobb, 1975)"
    }
  ],
  "supply": [
    {
      "subject": "Beta fibre (Owens-Corning) and Teflon coating",
      "abundance": "Not found in any source read.",
      "producers": [],
      "critical_lists": [],
      "substitutes": [],
      "source": "fire-fibers-2017",
      "where": "Development of Beta Fiber; Summary of production (quotation of Orndoff, 2016)"
    },
    {
      "subject": "Fluorspar (calcium fluoride), the feedstock for the hydrogen fluoride used to make PTFE",
      "abundance": "World fluorspar reserves are 330,000 thousand metric tons (rounded) in the same USGS table; reserves for the Beta glass fibre and the Teflon coating are not found in any source read.",
      "producers": [],
      "critical_lists": [],
      "substitutes": [],
      "source": "usgs-mcs2026-fluorspar",
      "where": "Fluorspar chapter, Domestic Production and Use paragraph and Net import reliance row; World Mine Production and Reserves table, 2025 column"
    }
  ],
  "media": [],
  "documents": [
    {
      "title": "Research, development and application of noncombustible Beta fiber structures (Dillon and Cobb, Owens-Corning Fiberglas Corp., 1975)",
      "type": "report",
      "url": "https://ntrs.nasa.gov/citations/19750021113",
      "year": 1975
    },
    {
      "title": "Flame Retardant Fibers for Human Space Exploration - Past, Present, and Future (NASA NTRS 20170008542)",
      "type": "report",
      "url": "https://ntrs.nasa.gov/citations/20170008542",
      "year": 2017
    },
    {
      "title": "Artemis Suit Material Project Overview, ICES-2025-56 (Jones, McFarland, Rodgers-Ahnen, Rhodes, 54th ICES, Prague, 2025)",
      "type": "paper",
      "url": "https://ntrs.nasa.gov/citations/20250003726",
      "year": 2025
    },
    {
      "title": "Mineral Commodity Summaries 2026, Fluorspar (U.S. Geological Survey)",
      "type": "report",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-fluorspar.pdf",
      "year": 2026
    },
    {
      "title": "Safety data sheet, POLYFLON PTFE M-532 (Daikin Chemicals, printed 20.01.2011)",
      "type": "sds",
      "url": "https://www.daikinchemicals.com/library/pb_common/pdf/sds/Fluoropolymer/PTFE-M/sds-m-532-E_20110120.pdf",
      "year": 2011
    }
  ],
  "gaps": [
    "No hazard data for the woven Beta cloth or its PTFE coating was found. The hazards entries use NIOSH's generic fibrous glass entry and Daikin's 2011 safety data sheet for a PTFE product (POLYFLON PTFE M-532), not Beta fabric. No PubChem GHS entry for PTFE was read in this run, and no GHS classification of Beta fibre was found.",
    "No composition by weight or share for the Beta glass was printed in any source read; the glass is described only as high-purity glass.",
    "Producer country shares for the Beta glass fibre and the Teflon coating were not found. Critical-mineral list status for fluorspar was not read in this run.",
    "Recycling and substitutes for Beta cloth were not found in any source read.",
    "No flight or vacuum outgassing numbers for Beta cloth were printed; the 2017 and 1975 papers say the fabric met NASA criteria for outgassing, toxicity and odour without giving the numbers.",
    "Radiation tolerance is stated qualitatively (ICES 2025 says the glass is resistant to solar and ionizing radiation) but no dose or retention figure was printed.",
    "The brief describes Beta cloth as an MLI outer layer; the 1975 report says Beta marquisette was a spacer between aluminised Kapton layers in ITMG superinsulation, so no outer-layer use is stated here.",
    "The Ortho Fabric design goals from ICES 2025 (goal weight 10 oz/yd2, breaking strength 180 lbf/in, tear strength 20 lbf/in, flex life 100,000 cycles, quoted from the 1974 ILC recommendation) are goals for the successor shell, not measured Beta properties, so they are not used as values here.",
    "Ortho Fabric test results from ICES 2025 (for example tumbler losses) belong to another fabric and are not used as Beta values.",
    "Coating level 1 fill breaking strength (X4190B) is not legible in the scanned table and is left out.",
    "Fill value for air permeability and Taber abrasion at coating level 2 are not printed in the table as legible text and are left out.",
    "Beta cloth flammability at reduced oxygen levels (LOI or pressure test results) was not found; only the 16.5 psia noncombustible statement is printed.",
    "Degradation temperature is recorded as degradation_temperature, a name not in property-canon.yaml; the same applies to filament_diameter, noncombustible_pressure_in_oxygen, tongue_tear, elmendorf_tear, stoll_flat_abrasion, taber_abrasion_to_fabric_failure, air_permeability, seam_strength, ignition_loss, thickness, mit_flex_cycles, mullen_burst and yarn_count.",
    "Ultimate tensile strength is printed in lbs/in and lbs/inch, not in MPa; the importer must convert these units.",
    "No CAS number for Beta cloth was printed in any source read. The Daikin safety data sheet prints CAS 9002-84-0 for POLYFLON PTFE M-532, which is PTFE in general, not the Beta fabric or its coating, so it is not used as the identity CAS.",
    "Eight sources are cited. Four are NASA or Wikipedia items read in an earlier pass; this pass added NIOSH, USGS and Daikin, plus Wikipedia Fiberglass for glass type composition only.",
    "No images were added to this profile; no licensed Beta cloth image was fetched in this run. The media section is therefore absent.",
    "No standard abbreviation for Beta cloth was printed in any source read, so the abbreviation field is absent.",
    "The ICES 2025 paper's Ortho Fabric test data (sections on tumbler, dust and temperature) were read and are not included as Beta properties."
  ],
  "story": {
    "why": "Beta cloth is a PTFE-coated glass textile. It was made from Beta fibre, an extra-fine glass filament (3.5 to 3.8 microns) that Owens-Corning developed under NASA contract. Its fibre fineness gave the fabric drape and flexibility. The glass is inorganic, so it does not burn in pure oxygen up to 16.5 psia, which made it the choice for the Apollo spacecraft and spacesuit. Its main weakness is abrasion, and a 1974 NASA contract sought a replacement shell layer for it.",
    "uses": [
      {
        "where": "Apollo spacesuit outer layer",
        "line": "Woven Beta fabrics were selected for the outer layer of Apollo space suits and flight suits, for the interior liner of the Apollo command module, and for several crew equipment items and fire protective covers."
      },
      {
        "where": "Space Shuttle cargo bay cover",
        "line": "The largest use of Beta fabric in the Shuttle Orbiter was the contamination control cover of the cargo bay. Between 1967 and 1990 approximately 10450 lb of Beta fabrics were used across Apollo, Skylab, Apollo-Soyuz, Shuttle and Spacelab."
      },
      {
        "where": "Insulation spacer",
        "line": "Beta marquisette was used as a spacer between aluminised Kapton layers in the ITMG superinsulation, according to the 1975 report."
      }
    ],
    "can_do": [
      {
        "label": "Heat in oxygen",
        "line": "In a 100 percent oxygen atmosphere, Beta fibre was noncombustible up to 16.5 psia (Dillon and Cobb, 1975). It kept its service range from -184 °C to 482 °C (NASA, 2017).",
        "scope": "material",
        "value": "16.5 psia"
      },
      {
        "label": "Weight",
        "line": "The Teflon-coated style X4190B weighed 6.6 oz/sq yd at coating level 1 and 7.8 oz/sq yd at coating level 2 (Dillon and Cobb, 1975). The X4484 fabric, woven from Teflon-coated yarn, weighed 6.18 oz/sq yd.",
        "scope": "material",
        "value": "6.6 oz/sq yd"
      },
      {
        "label": "Fine fibre",
        "line": "The Beta filament is 3.5 to 3.8 microns in diameter, which the NASA 2017 paper says makes it a microfiber in modern textile terms.",
        "scope": "material",
        "value": "3.5 to 3.8 microns"
      }
    ],
    "compare": "Beta cloth is a fine glass textile, while the later Ortho Fabric is a two-layer blend of Gore-Tex, Nomex and Kevlar. The 2025 ICES paper says Beta cloth was noncombustible in oxygen and resisted atomic oxygen when tightly woven, but it failed the NASA rotary tumbler abrasion test. Ortho Fabric, by contrast, survived the same test with measurable degradation. The numbers in this profile are from the 1975 Owens-Corning report and the 2017 NASA paper, not from the Ortho Fabric data.",
    "compare_rows": [
      {
        "label": "Maximum service temperature",
        "benchmark": "max_service_temp",
        "scope": "material"
      },
      {
        "label": "Breaking strength, X4190B warp",
        "benchmark": "ultimate_tensile_strength",
        "scope": "material"
      },
      {
        "label": "Taber abrasion to fabric failure",
        "benchmark": "taber_abrasion_to_fabric_failure",
        "scope": "material"
      }
    ],
    "handling": [
      "Beta cloth is a glass textile, and its fibres crack when sewn and flexed. Handle it with care and mark patterns with chalk.",
      "Coat the yarns before weaving if tear strength matters; coating the woven surface reduced tear strength.",
      "Do not rely on it for lunar abrasion: the fabric was degraded by dust after short use."
    ],
    "good_for": [
      "Oxygen-rich spacecraft and spacesuit layers where non-combustibility matters, as shown by the 16.5 psia statement.",
      "Fine, flexible glass textiles for covers and liners, as used on the Shuttle cargo bay."
    ],
    "watch_out": [
      "Abrasion: the fabric frayed and broke under lunar dust in Apollo suits and failed the NASA rotary tumbler test.",
      "Fragile glass fibres: they crack when sewn and flexed, and weaving needed silicone oil.",
      "The coating changes the handling: Teflon on the woven surface reduced tear strength."
    ],
    "verdict": "Beta cloth is a proven noncombustible glass textile for Apollo and Shuttle use, but its abrasion resistance made NASA design a successor shell for lunar surface work.",
    "recipe": {
      "line": "Beta cloth is a woven glass fabric, made from Beta fibre filaments of 3.5 to 3.8 microns, and coated with PTFE (Teflon). The coating repeat unit is (CF2-CF2)n, built from tetrafluoroethylene. The composition of the Beta glass is not printed in any source read. For glass fibre types in general, Wikipedia describes E-glass as \"alumino-borosilicate glass with less than 1% w/w alkali oxides\"; that describes E-glass, not Beta fibre.",
      "parts": [
        {
          "name": "Beta glass fibre",
          "symbol": "glass",
          "role": "The load-bearing textile. Fine filaments give the fabric drape and flexibility, and the glass itself is inorganic."
        },
        {
          "name": "PTFE coating (Teflon)",
          "symbol": "CF2-CF2",
          "role": "Applied to the yarns or the woven surface to ease weaving and improve abrasion resistance. Repeat unit per the Wikipedia Production section; the coating processes are described in the 1975 report."
        }
      ]
    },
    "risk_groups": [
      {
        "title": "For people",
        "lead": "The sources read do not give a hazard classification for the woven fabric, and no safety data sheet was read in this run.",
        "points": [
          {
            "label": "Fibres",
            "line": "The glass fibres are fragile. They crack when sewn and flexed, so the fabric is handled with care during garment work."
          },
          {
            "label": "Fire in oxygen",
            "line": "Beta cloth was noncombustible in 100 percent oxygen up to 16.5 psia, the condition of the Apollo capsule."
          },
          {
            "label": "Dust",
            "line": "Lunar dust was embedded in the Apollo-era weave, according to post-flight inspection."
          }
        ]
      },
      {
        "title": "In service",
        "lead": "These results come from Apollo-era inspections and from a laboratory rotary tumbler test, not from incidents in service.",
        "points": [
          {
            "label": "Lunar surface",
            "line": "Post-Apollo inspection found fibres frayed and broken by lunar dust and abrasion after short use. The fabric was not durable enough for a sustained lunar presence."
          },
          {
            "label": "Laboratory abrasion",
            "line": "Beta cloth failed the NASA rotary tumbler abrasion test and was excluded from the 2025 trade study as a benchmark."
          }
        ]
      },
      {
        "title": "Handling and manufacture",
        "points": [
          {
            "label": "Assembly",
            "line": "Chalk bags were used to mark patterns, and seam edges were coated with cement, to keep the fabric from degrading during garment work."
          },
          {
            "label": "Coating",
            "line": "Teflon on the woven surface reduced tear strength. Coating the yarns before weaving fixed that but was costly."
          }
        ]
      }
    ]
  },
  "updated": "2026-11-01",
  "review": {
    "status": "draft",
    "method": "assistant",
    "checked_values": 21,
    "unreachable": 0,
    "caveats": 3,
    "note": "Written by an AI assistant on 2026-11-01. Values come from the NASA reports and paper and from Wikipedia for the coating repeat unit (read earlier). The hazard, supply and NIOSH and Daikin SDS facts were read in the 2026-11-01 deepen pass from NIOSH, USGS MCS 2026 and the Daikin SDS. Scanned-table values were checked visually where the text layer was unclear. Not checked against a second reader."
  },
  "sources": {
    "dillon-cobb-1975": {
      "title": "Research, development and application of noncombustible Beta fiber structures",
      "id": "NTRS 19750021113 (J. J. Dillon and E. S. Cobb, Owens-Corning Fiberglas Corp., 1975)",
      "url": "https://ntrs.nasa.gov/citations/19750021113",
      "year": 1975,
      "kind": "report",
      "license": "public domain (NASA)"
    },
    "fire-fibers-2017": {
      "title": "Flame Retardant Fibers for Human Space Exploration - Past, Present, and Future",
      "id": "NTRS 20170008542",
      "url": "https://ntrs.nasa.gov/citations/20170008542",
      "year": 2017,
      "kind": "report",
      "license": "public domain (NASA)"
    },
    "ices-2025-jones": {
      "title": "Artemis Suit Material Project Overview",
      "id": "ICES-2025-56, 54th International Conference on Environmental Systems, Prague, 13-17 July 2025; NTRS 20250003726",
      "url": "https://ntrs.nasa.gov/citations/20250003726",
      "year": 2025,
      "kind": "paper",
      "license": "public domain (NASA)"
    },
    "wiki-ptfe": {
      "title": "Polytetrafluoroethylene (Wikipedia)",
      "id": "en.wikipedia.org, read 2026-11-01; used for the coating repeat unit only",
      "url": "https://en.wikipedia.org/wiki/Polytetrafluoroethylene",
      "kind": "web",
      "license": "CC BY-SA 4.0 (Wikipedia)"
    },
    "niosh-npg-fibrous-glass": {
      "title": "NIOSH Pocket Guide to Chemical Hazards, fibrous glass entry",
      "id": "CDC/NIOSH npgd0288, read 2026-11-01",
      "url": "https://www.cdc.gov/niosh/npg/npgd0288.html",
      "kind": "handbook",
      "license": "public domain (US government)"
    },
    "usgs-mcs2026-fluorspar": {
      "title": "Mineral Commodity Summaries 2026, Fluorspar",
      "id": "USGS, DOI 10.3133/mcs2026, read 2026-11-01",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-fluorspar.pdf",
      "year": 2026,
      "kind": "report",
      "license": "public domain (USGS)"
    },
    "daikin-ptfe-sds": {
      "title": "Safety data sheet, POLYFLON PTFE M-532 (Daikin Chemicals)",
      "id": "article 532, CAS 9002-84-0, printed 20.01.2011, read 2026-11-01",
      "url": "https://www.daikinchemicals.com/library/pb_common/pdf/sds/Fluoropolymer/PTFE-M/sds-m-532-E_20110120.pdf",
      "year": 2011,
      "kind": "datasheet",
      "license": "manufacturer safety data sheet, used for the printed facts only"
    },
    "wiki-fiberglass": {
      "title": "Fiberglass (Wikipedia)",
      "id": "en.wikipedia.org, read 2026-11-01; used for glass fibre type composition only",
      "url": "https://en.wikipedia.org/wiki/Fiberglass",
      "kind": "web",
      "license": "CC BY-SA 4.0 (Wikipedia)"
    }
  },
  "license": "CC-BY-4.0",
  "url": "https://spacemushroom.com/profiles/beta-cloth/"
}