spore: profile
id: afrsi-blanket
spore_version: 0.2
family: glass-and-composites
name: AFRSI (advanced flexible reusable surface insulation blanket)
abbreviation: AFRSI
role: thermal-protection-blanket
category: thermal-protection
type: flexible-blankets
summary: |
  AFRSI is a quilted flexible blanket of woven silica fabric, fibrous silica batting and woven S-glass, sewn with silica thread. NASA's TPSX record gives its thru-the-thickness thermal conductivity as 0.0329 W/m-K and its multiple-use temperature limit as 922 K. The blanket was used on many Shuttle Orbiter leeside surfaces. TPSX says it costs less to install than tile thermal protection but is less suitable for high or fluctuating aerodynamic loads, and that it becomes brittle after thermal exposure.
best_for: Reusable insulation on surfaces without high or fluctuating aerodynamic loads, where the installed cost matters more than surface strength
weakest_at: Aerodynamic loads (TPSX says it is less suitable than tile for high or fluctuating loads) and brittleness after thermal exposure
identity:
  formula: Woven silica (Astroquartz) outer fabric, fibrous silica batting (Q-felt) and woven S-glass inner fabric, sewn with Astroquartz thread
  source: tpsx-afrsi
  where: Description and Composition
  designations:
    - system: Trade name
      code: Shuttle AFRSI
      source: tpsx-afrsi
      where: Description, which says it is also called Type II or Shuttle AFRSI
    - system: Trade name
      code: Type II
      source: tpsx-afrsi
      where: Description, which says it is also called Type II or Shuttle AFRSI
tags:
  environments:
    - re-entry
  stresses:
    - extreme-heat
  applications:
    - heat-shields
properties:
  - benchmark: additive_areal_weight
    value: 1.46
    unit: kg/m^2
    scope: material
    conditions:
      basis: Additive areal weight, added to density times thickness to give total areal weight (TPSX footnote 2)
      uncertainty_as_printed: N/A
      stp: assumed/assumed in TPSX STP column
    method: TPSX Properties at Standard Conditions table. TPSX gives no measurement method, so the status is set to calculated.
    status: calculated
    source: tpsx-afrsi
    where: Properties at Standard Conditions table, Additive Areal Weight row (footnote 2)
  - benchmark: thermal_conductivity
    value: 0.0329
    unit: W/m-K
    scope: material
    conditions:
      direction: Through the thickness, normal to the blanket plane only
      stp: TRUE in TPSX STP column
      uncertainty_as_printed: 1.64e-03 W/m-K
    method: TPSX Properties at Standard Conditions table. The page says conductivity is directional and gives only the normal-to-plane value (footnote 3).
    status: ground
    source: tpsx-afrsi
    where: Properties at Standard Conditions table, Thermal Conductivity, Thru-the-Thickness row (footnote 3)
  - benchmark: emissivity
    value: 0.87
    unit: '-'
    scope: material
    conditions:
      coating: C-9 coated blanket with Astroquartz outer fabric (the page gives no uncoated value)
      uncertainty_as_printed: '4.35e-02'
    method: TPSX Properties at Standard Conditions table, footnote 4, which says the emissivity values are for the C-9 coated blanket with Astroquartz outer fabric.
    status: ground
    source: tpsx-afrsi
    where: Properties at Standard Conditions table, Emissivity row (footnote 4)
  - benchmark: replacement_fraction_per_flight
    value: 0.018
    unit: '-'
    scope: material
    conditions:
      basis: Fraction of the blanket replaced per flight, based on Shuttle experience
      uncertainty_as_printed: '9.00e-04'
    method: TPSX lists the measurement type as predicted (footnote 10).
    status: calculated
    source: tpsx-afrsi
    where: Properties at Standard Conditions table, Replacement Fraction per Flight row (footnote 10)
  - benchmark: thickness
    value: 0.24
    value_high: 1.94
    unit: inch
    scope: material
    conditions:
      basis: Demonstrated thickness range; the nominal thickness is 1.0 inch
      nominal_thickness: 1.0 inch
    method: TPSX footnote 1 to the Properties at Standard Conditions table, which gives the nominal and demonstrated thicknesses.
    status: ground
    source: tpsx-afrsi
    where: Properties at Standard Conditions table, footnote 1
corrosion:
  - environment: Thermal exposure (reentry heating cycles)
    headline: TPSX says the blanket becomes brittle after thermal exposure.
    effect: The TPSX description says AFRSI 'becomes brittle after thermal exposure'. The record gives no temperature, time or cycle count for when this starts.
    rating: moderate
    conditions:
      exposure: Thermal exposure; temperature, duration and number of cycles not stated on the TPSX record
    source: tpsx-afrsi
    where: Description
risks:
  hazards:
    - text: PubChem's aggregated record for silica (CID 24261), the chemical behind silica fibre, lists it as not classified. 7724 of 9127 company reports say it does not meet GHS hazard criteria.
      ghs: []
      source: pubchem-silica
      where: GHS Classification, top-level entry (EC 231-545-4)
    - text: A separate PubChem entry for amorphous silica (EC 601-216-3) lists H315 (causes skin irritation), H319 (causes serious eye irritation) and H335 (may cause respiratory irritation). The record does not say which silica form the AFRSI fibres are.
      ghs:
        - H315
        - H319
        - H335
      source: pubchem-silica
      where: GHS Classification, amorphous silica entry (EC 601-216-3)
  failure_risks:
    - mode: Brittleness after thermal exposure
      trigger: Thermal exposure; the TPSX record gives no dose
      consequence: The blanket becomes brittle, according to the TPSX description.
      severity: moderate
      source: tpsx-afrsi
      where: Description
    - mode: Poor tolerance of high or fluctuating aerodynamic loads
      trigger: High or fluctuating aerodynamic loads
      consequence: TPSX says AFRSI is less suitable for these loads than tile thermal protection. The record gives no failure load.
      severity: moderate
      source: tpsx-afrsi
      where: Description
  side_effects:
    - text: TPSX says installation time, inspection and repair time, and replacement fraction 'may vary drastically' if the environment differs from the Shuttle's.
      affects: Maintenance planning outside the Shuttle environment
      source: tpsx-afrsi
      where: Footnotes 8, 9 and 10 of the Properties at Standard Conditions table
  handling:
    - text: Wikipedia says AFRSI required much less maintenance than the LRSI tiles it replaced, and had about the same thermal properties.
      source: wiki-sts-tps
      where: Non-tile TPS, Flexible Insulation Blankets/AFRSI subsection
    - text: TPSX gives inspection and repair time of 37200 s/m^2 per flight, a predicted value based on Shuttle experience.
      source: tpsx-afrsi
      where: Properties at Standard Conditions table, Inspection/Repair Time per Flight row
  mitigations:
    - text: Keep the blanket below its multiple-use temperature limit of 922 K. TPSX gives the single-use limit as 1090 K.
      source: tpsx-afrsi
      where: Properties at Standard Conditions table, Multiple Use and Single Use Temperature Limit rows
    - text: 'Place it on leeside surfaces: TPSX says AFRSI was used on many Shuttle Orbiter leeside surfaces and is less suitable for high or fluctuating aerodynamic loads.'
      source: tpsx-afrsi
      where: Description
uses:
  - application: heat-shields
    device: Space Shuttle Orbiter leeside surfaces
    example: TPSX says AFRSI was used on many Shuttle Orbiter leeside surfaces. It has a lower installed cost than tile thermal protection.
    source: tpsx-afrsi
    where: Description
  - application: heat-shields
    device: Orbital Maneuvering System pods, then tile replacement on Columbia
    example: Wikipedia says AFRSI was first used on the OMS pods of Challenger, used much more extensively from Discovery onward, and replaced many LRSI tiles on Columbia after the loss of Challenger.
    source: wiki-sts-tps
    where: Non-tile TPS, Flexible Insulation Blankets/AFRSI subsection
supply: []
media: []
documents:
  - title: 'NASA Ames TPSX material record: AFRSI Blanket (Material id 12)'
    type: database
    url: https://tpsx.arc.nasa.gov/Material?id=12
    year: 2006
  - title: 'NASA Ames TPSX material record: AFRSI-2500 Blanket (Material id 14), a separate grade'
    type: database
    url: https://tpsx.arc.nasa.gov/Material?id=14
    year: 2006
  - title: Composite Multilayer Insulations for Thermal Protection of Aerospace Vehicles (NASA TM 101071)
    type: report
    url: https://ntrs.nasa.gov/api/citations/19900000867/downloads/19900000867.pdf
    year: 1989
  - title: 'PubChem: Silica (CID 24261), GHS classification'
    type: database
    url: https://pubchem.ncbi.nlm.nih.gov/compound/24261
    year: 2026
gaps:
  - 'Supply: no producer, feedstock or country data for Astroquartz, Q-felt or S-glass was read in this run, so the supply list is empty.'
  - 'Recipe: no atomic or mass shares for the silica, glass or thread constituents were read, so the recipe parts carry no atoms or atomic weights.'
  - 'Names not in spores/property-canon.yaml, used in snake_case: additive_areal_weight, emissivity, multiple_use_temperature_limit, single_use_temperature_limit, purchase_cost, installation_time, inspection_repair_time_per_flight, replacement_fraction_per_flight, thickness.'
  - TPSX reuse flight limit is printed as 0.0 with no explanation, so it is left out.
  - No flight measurement of AFRSI density, conductivity or temperature was read in this run. Cost, installation, inspection and replacement values are predicted from Shuttle experience.
  - The Boeing Shuttle Operational Data Book, which TPSX cites for the temperature limits, was not opened.
  - No oxidation, humidity, atomic-oxygen or coating-durability test result for AFRSI was read in this run. The only ageing statement is the TPSX brittleness line.
  - The NASA TM 101071 (1989) compares a composite multilayer insulation with an AFRSI of equal thickness and density. Its AFRSI backface-temperature results are in figures and garbled PDF text, so no numbers were taken from it.
  - The hazard entries come from the PubChem silica summary, not from a supplier safety data sheet for an AFRSI blanket. The H315, H319 and H335 codes belong to the amorphous silica entry.
  - AFRSI-2500 (TPSX id 14) and AFRSI-2200 (TPSX id 13) are separate grades with their own records. Their values are not used in this profile.
sources:
  tpsx-afrsi:
    title: 'NASA Ames TPSX material record: AFRSI Blanket (Material id 12)'
    id: TPSX Material id=12; record last modified 2001-10-01; property table last modified 2006-01-05
    url: https://tpsx.arc.nasa.gov/Material?id=12
    year: 2006
    kind: database
    license: public domain (NASA)
  tpsx-afrsi-2500:
    title: 'NASA Ames TPSX material record: AFRSI-2500 Blanket (Material id 14)'
    id: TPSX Material id=14; separate grade, consulted to confirm the variant is not this grade
    url: https://tpsx.arc.nasa.gov/Material?id=14
    year: 2006
    kind: database
    license: public domain (NASA)
  ntrs-tm-101071:
    title: Composite Multilayer Insulations for Thermal Protection of Aerospace Vehicles (D. A. Kourtides and W. C. Pitts)
    id: NASA TM 101071 (NTRS 19900000867), February 1989
    url: https://ntrs.nasa.gov/api/citations/19900000867/downloads/19900000867.pdf
    year: 1989
    kind: report
    license: public domain (NASA)
  wiki-sts-tps:
    title: 'Wikipedia: Space Shuttle thermal protection system'
    id: Wikipedia article, Non-tile TPS section (history and use only)
    url: https://en.wikipedia.org/wiki/Space_Shuttle_thermal_protection_system
    year: 2026
    kind: web
    license: CC BY-SA 4.0 (text cited, not reproduced)
  pubchem-silica:
    title: PubChem compound record, Silica (CID 24261), GHS classification
    id: CID 24261 (silicon dioxide, EC 231-545-4); amorphous silica entry EC 601-216-3
    url: https://pubchem.ncbi.nlm.nih.gov/compound/24261
    year: 2026
    kind: database
    license: public domain (NCBI)
license: public domain (NASA TPSX and NTRS); CC BY-SA 4.0 Wikipedia text cited only
updated: '2026-11-01'
review:
  status: draft
  method: assistant
  checked_values: 5
  unreachable: 0
  caveats: 2
  note: Written by an AI assistant on 2026-11-01 from the TPSX AFRSI record (id 12), the NASA TM 101071 PDF, the Wikipedia Space Shuttle TPS article and the PubChem silica record, all fetched in this run. TPSX values are copied as printed with units.
story:
  recipe:
    line: AFRSI is a sewn, quilted blanket. Its outer fabric is woven silica (Astroquartz), its core is fibrous silica batting (Q-felt), and its inner fabric is woven S-glass. Astroquartz thread stitches the three layers together. The record gives no atomic or mass shares for these constituents.
    parts:
      - name: Astroquartz outer fabric
        role: Woven silica skin on the hot side. It carries the blanket's emissive coating, which the TPSX values are measured on.
      - name: Q-felt batting
        role: Fibrous silica insulating core. Its density and thickness set the blanket's areal weight, per TPSX footnote 2.
      - name: S-glass inner fabric
        role: Woven glass liner on the structure side of the blanket.
      - name: Astroquartz thread
        role: Stitching that holds the quilted layers together.
  risk_groups:
    - title: For people
      level: 0
      verdict: Not classified as hazardous in the silica record
      lead: The chemical behind silica fibre is not classified by most PubChem reporters. One related amorphous silica entry does carry irritant codes, so the dust should be controlled.
      points:
        - label: The silica record
          line: PubChem's silica summary lists the compound as not classified. 7724 of 9127 company reports say it does not meet GHS hazard criteria.
        - label: Amorphous silica
          line: A separate amorphous silica entry lists H315 (skin irritation), H319 (serious eye irritation) and H335 (respiratory irritation). The AFRSI fibre form is not stated in that record.
    - title: If the blanket is over-stressed
      lead: 'TPSX describes two limits: brittleness after heat exposure and poor tolerance of high or fluctuating aerodynamic loads. It gives no failure figure for either.'
      points:
        - label: Brittleness
          line: The TPSX description says the blanket becomes brittle after thermal exposure.
        - label: Aerodynamic loads
          line: TPSX says AFRSI is less suitable than tile thermal protection for high or fluctuating aerodynamic loads.
  why: AFRSI, the advanced flexible reusable surface insulation, is a quilted blanket of silica fabric and silica batting. A thermal protection system (TPS) is the outer layer that keeps the vehicle structure within its temperature limit during reentry. TPSX says AFRSI is used on many Shuttle Orbiter leeside surfaces. Wikipedia says it replaced many of the tiles on Columbia after the loss of Challenger. TPSX also says it costs less to install than tile TPS, but is less suitable for high or fluctuating aerodynamic loads.
  uses:
    - where: Shuttle Orbiter leeside surfaces
      line: TPSX says AFRSI was used on many Shuttle Orbiter leeside surfaces. It has a lower installed cost than tile thermal protection, according to the same record.
    - where: OMS pods, then tile replacement
      line: Wikipedia says AFRSI was first used on the OMS pods of Challenger and was used much more extensively from Discovery onward. It replaced many LRSI tiles on Columbia after the loss of Challenger.
  can_do:
    - label: Thermal conductivity
      benchmark: thermal_conductivity
      value: 0.0329 W/m-K
      line: Through the thickness, AFRSI conducts heat at 0.0329 W/m-K at standard conditions, per TPSX. The record gives only the normal-to-plane value.
    - label: Use temperature
      benchmark: multiple_use_temperature_limit
      value: 922 K
      line: The multiple-use temperature limit is 922 K. TPSX lists the single-use limit as 1090 K, and both values trace to a Boeing Shuttle data book.
    - label: Emissivity
      benchmark: emissivity
      value: '0.87'
      line: The emissivity is 0.87 for the C-9 coated blanket with Astroquartz outer fabric. The record gives no uncoated value.
    - label: Thickness
      benchmark: thickness
      value: 0.24 to 1.94 inch
      line: The nominal thickness is 1.0 inch, with a demonstrated range from 0.24 to 1.94 inch, per TPSX footnote 1.
    - label: Replacement
      benchmark: replacement_fraction_per_flight
      value: 0.018 per flight
      line: TPSX predicts that 0.018 of the blanket is replaced per flight, based on Shuttle experience. The record warns that this may vary drastically in another environment.
  compare: AFRSI is a flexible blanket, so it is set against tile thermal protection only on the points the TPSX record states. The record says AFRSI costs less to install than tile but tolerates high or fluctuating aerodynamic loads less well. Its through-thickness conductivity is 0.0329 W/m-K and its multiple-use limit is 922 K. The AFRSI-2500 variant is a separate grade with its own record and is not compared here.
  compare_rows:
    - label: Emissivity of the coated blanket
      benchmark: emissivity
    - label: Conductivity through the thickness
      benchmark: thermal_conductivity
    - label: Multiple-use temperature limit
      benchmark: multiple_use_temperature_limit
  handling:
    - Keep the blanket below its multiple-use limit of 922 K. TPSX gives the single-use limit as 1090 K.
    - Plan for inspection and repair of 37200 s/m^2 per flight. TPSX calls this a prediction that may vary by environment.
    - Control dust from loose silica fibre. The amorphous silica PubChem entry lists H335, which is respiratory irritation.
  good_for:
    - Lower installed cost than tile thermal protection, according to TPSX.
    - Surfaces without high or fluctuating aerodynamic loads, which is where the Shuttle used it on many leeside surfaces.
  watch_out:
    - Brittleness after thermal exposure, per the TPSX description.
    - Less suitable than tile for high or fluctuating aerodynamic loads, per TPSX.
    - Cost and maintenance figures are predicted from Shuttle experience and may vary drastically elsewhere.
    - AFRSI-2500, an alumina variant with its own TPSX record, is a different grade and is not covered here.
  verdict: AFRSI is a reusable flexible blanket with a lower installed cost than tile thermal protection, used on many Shuttle leeside surfaces. Its limits are brittleness after thermal exposure and weak tolerance of high or fluctuating aerodynamic loads.