AFRSI (advanced flexible reusable surface insulation blanket) AFRSI
Woven silica (Astroquartz) outer fabric, fibrous silica batting (Q-felt) and woven S-glass inner fabric, sewn with Astroquartz thread
Also known as Shuttle AFRSI, Type II
AFRSI is a quilted flexible blanket of woven silica fabric, fibrous silica batting and woven S-glass, sewn with silica thread.
Evidence level
2 of 5
Lab-measured
- 0Predicted only. No one has made it, or no measurement exists.
- 1Calculated. Only calculated or predicted values from sources.
- 2Lab-measured. Measured properties with their conditions stated.
- 3Space-relevant tests. Measured in conditions relevant to space, such as vacuum or atomic oxygen.
- 4Ground-qualified. Qualified for an application on the ground.
- 5Flown or field-proven. Flight or field results exist.
Thermal conductivity
0.0329 W/m-K
Use temperature
922 K
Emissivity
0.87
Thickness
0.24 to 1.94 inch
Replacement
0.018 per flight
Recipe, share of the weight
- not statedAstroquartz outer fabric
- not statedQ-felt batting
- not statedS-glass inner fabric
- not statedAstroquartz thread
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
Risk at a glance
- People None found. Not classified as hazardous in the silica record
- If it fails Moderate. Brittleness after thermal exposure
- Corrosion Moderate. TPSX says the blanket becomes brittle after thermal exposure.
Quick facts: AFRSI
| Property | Value | Basis |
|---|---|---|
| Thermal conductivity | 0.033 W/(m·K) | 1 sourced value |
What is the thermal conductivity of AFRSI?
AFRSI has a thermal conductivity of 0.033 W/(m·K). The source and test conditions are listed in the properties table on this page.
What are the other names and codes for AFRSI?
AFRSI is also written as Shuttle AFRSI, Type II. Each code is printed in the source listed beside it in the designations table.
What is AFRSI used for?
Uses recorded in the sources include Space Shuttle Orbiter leeside surfaces; Orbital Maneuvering System pods, then tile replacement on Columbia.
Why it exists
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.
Where it's used
Shuttle Orbiter leeside surfaces
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.
OMS pods, then tile replacement
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.
Recipe
Woven silica (Astroquartz) outer fabric, fibrous silica batting (Q-felt) and woven S-glass inner fabric, sewn with Astroquartz thread
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.
| Ingredient | Share of the weight | What it does |
|---|---|---|
| Astroquartz outer fabric | not stated | Woven silica skin on the hot side. It carries the blanket's emissive coating, which the TPSX values are measured on. |
| Q-felt batting | not stated | Fibrous silica insulating core. Its density and thickness set the blanket's areal weight, per TPSX footnote 2. |
| S-glass inner fabric | not stated | Woven glass liner on the structure side of the blanket. |
| Astroquartz thread | not stated | Stitching that holds the quilted layers together. |
Weight shares are as printed in the sources.
What it can do
Thermal conductivity
0.0329 W/m-K
measured
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.
Use temperature
922 K
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.
Emissivity
0.87
measured
The emissivity is 0.87 for the C-9 coated blanket with Astroquartz outer fabric. The record gives no uncoated value.
Thickness
0.24 to 1.94 inch
measured
The nominal thickness is 1.0 inch, with a demonstrated range from 0.24 to 1.94 inch, per TPSX footnote 1.
Replacement
0.018 per flight
worked out from the formula
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.
How it compares
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.
The same measurements for each material, so you can compare them. Each row names the key condition under the value; the full conditions and methods are in the numbered notes under Technical details. Compare every grade in the family.
Why choose it, and why not
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 for
- 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.
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.
Technical details
For scientists and researchers. Everything above comes from the record below: every number with its method, its conditions and its source.
Other names and standards
The same grade under other systems, as datasheets and standards print them. Each code was checked against the page it comes from.
| System | Codes |
|---|---|
| Trade name | Shuttle AFRSI, Type II |
Notes
The method, full conditions and any caveat for the numbered rows above.
| # | Measurement | Method | Conditions | Caveat |
|---|---|---|---|---|
| 1 | additive areal weight | TPSX Properties at Standard Conditions table. TPSX gives no measurement method, so the status is set to calculated. | basis Additive areal weight, added to density times thickness to give total areal weight (TPSX footnote 2)uncertainty as printed N/Astp assumed/assumed in TPSX STP column | — |
| 2 | Thermal conductivity | TPSX Properties at Standard Conditions table. The page says conductivity is directional and gives only the normal-to-plane value (footnote 3). | direction Through the thickness, normal to the blanket plane onlystp TRUE in TPSX STP columnuncertainty as printed 1.64e-03 W/m-K | — |
| 3 | emissivity | TPSX Properties at Standard Conditions table, footnote 4, which says the emissivity values are for the C-9 coated blanket with Astroquartz outer fabric. | coating C-9 coated blanket with Astroquartz outer fabric (the page gives no uncoated value)uncertainty as printed 4.35e-02 | — |
| 4 | replacement fraction per flight | TPSX lists the measurement type as predicted (footnote 10). | basis Fraction of the blanket replaced per flight, based on Shuttle experienceuncertainty as printed 9.00e-04 | — |
| 5 | thickness | TPSX footnote 1 to the Properties at Standard Conditions table, which gives the nominal and demonstrated thicknesses. | basis Demonstrated thickness range; the nominal thickness is 1.0 inchnominal thickness 1.0 inch | — |
Corrosion and compatibility
What happens when it meets other materials and environments.
| Environment | Concern | What happens |
|---|---|---|
| Thermal exposure (reentry heating cycles) | moderate | TPSX says the blanket becomes brittle after thermal exposure.1 |
| # | Environment | Details | Test conditions |
|---|---|---|---|
| 1 | Thermal exposure (reentry heating cycles) | The TPSX description says AFRSI 'becomes brittle after thermal exposure'. The record gives no temperature, time or cycle count for when this starts. | exposure Thermal exposure; temperature, duration and number of cycles not stated on the TPSX record |
Risks and side effects
Hazards to people, what happens when a cell overheats, and how the material is handled and stored.
For people
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.
- The silica record
- PubChem's silica summary lists the compound as not classified. 7724 of 9127 company reports say it does not meet GHS hazard criteria.
- Amorphous silica
- 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.
If the blanket is over-stressed
TPSX describes two limits: brittleness after heat exposure and poor tolerance of high or fluctuating aerodynamic loads. It gives no failure figure for either.
- Brittleness
- The TPSX description says the blanket becomes brittle after thermal exposure.
- Aerodynamic loads
- TPSX says AFRSI is less suitable than tile thermal protection for high or fluctuating aerodynamic loads.
Test details
The original wording and numbers from the sources, for readers who want them.
Failure risks
| Failure | Trigger and consequence |
|---|---|
| Brittleness after thermal exposuremoderate severity | Thermal exposure; the TPSX record gives no doseThe blanket becomes brittle, according to the TPSX description. |
| Poor tolerance of high or fluctuating aerodynamic loadsmoderate severity | High or fluctuating aerodynamic loadsTPSX says AFRSI is less suitable for these loads than tile thermal protection. The record gives no failure load. |
Side effects on surrounding parts
| Affects | Effect |
|---|---|
| Maintenance planning outside the Shuttle environment | TPSX says installation time, inspection and repair time, and replacement fraction 'may vary drastically' if the environment differs from the Shuttle's. |
Handling and storage
- Wikipedia says AFRSI required much less maintenance than the LRSI tiles it replaced, and had about the same thermal properties.
- TPSX gives inspection and repair time of 37200 s/m^2 per flight, a predicted value based on Shuttle experience.
Mitigations
- Keep the blanket below its multiple-use temperature limit of 922 K. TPSX gives the single-use limit as 1090 K.
- 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.
Documents
Datasheets, safety data sheets, papers and standards you can open.
| Document | Type | Year |
|---|---|---|
| NASA Ames TPSX material record: AFRSI Blanket (Material id 12) | database | 2006 |
| NASA Ames TPSX material record: AFRSI-2500 Blanket (Material id 14), a separate grade | database | 2006 |
| Composite Multilayer Insulations for Thermal Protection of Aerospace Vehicles (NASA TM 101071) | report | 1989 |
| PubChem: Silica (CID 24261), GHS classification | database | 2026 |
Full record
The complete spore, as stored. Free to reuse under public domain (NASA TPSX and NTRS); CC BY-SA 4.0 Wikipedia text cited only. Images keep the licence shown with each one.
Show the full YAML
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.
References
Every number above carries a reference number. Click one to see the source and where in it the value comes from.
| # | Source | Type | Year | Used for |
|---|---|---|---|---|
| NASA Ames TPSX material record: AFRSI Blanket (Material id 12) | database | 2006 | 14 values | |
| NASA Ames TPSX material record: AFRSI-2500 Blanket (Material id 14) | database | 2006 | 0 values | |
| Composite Multilayer Insulations for Thermal Protection of Aerospace Vehicles (D. A. Kourtides and W. C. Pitts) | report | 1989 | 0 values | |
| Wikipedia: Space Shuttle thermal protection system | web | 2026 | 2 values | |
| PubChem compound record, Silica (CID 24261), GHS classification | database | 2026 | 2 values |