AFRSI Blanket

Name: AFRSI Blanket
Database: NASA Ames Thermal Protection Materials
Category: Silicon-Based Reusable Composites: Composite Flexible Blankets
Composition: AFRSI is composed of 0.027-inch-thick Astroquartz outer fabric (MB0135-072 Type IV), Q-felt insulation, and 0.009-inch-thick S-glass inner fabric (MB0135-089) sewn together with Astroquartz thread.
Manufacturer: United Space Alliance. Inc., Schuler Corporation (maybe?), HiTemp Insulations, Oceaneering Thermal Systems
Technical Readiness Level: 9
Last Modified: 2001-10-01

Description:

  • AFRSI is a quilted blanket TPS consisting of a woven silica outer fabric, a woven glass inner fabric, and fibrous silica batting sewn together with silica thread. AFRSI is a quilted blanket TPS consisting of a woven silica outer fabric, a woven glass inner fabric, and fibrous silica batting sewn together with silica thread.This construction, also referred to as Type II AFRSI or Shuttle AFRSI, was developed from Type I AFRSI which has a thinner outer fabric. Type II AFRSI is currently used on a large percentage of the leeside surfaces of the Shuttle Orbiter. A blanket water-proofing agent is typically applied to AFRSI at the factory and again between flights. Currently AFRSI is flown on the shuttle vehicles with a C-9 coating on the outer surface. In addition to meeting emittance requirements, the coating makes the outer surface more rigid and helps to protect the blanket's top surface fibers from aerodynamically-induced abrasion. Compared to tile-type TPS, AFRSI's installed cost is low, but its aerodynamic capabilities are far more limited. It has a much rougher surface finish than most tiles and therefore has an increased propensity to force a laminar boundary layer into turbulence. This increased roughness can also produce markedly amplified local heating where boundary layers are relatively thin, such as the windward side of most reentry vehicles. Additionally, AFRSI has less tensile and shear strength compared to tiles, making it less applicable in areas of high aerodynamic loading; especially rapidly fluctuating aerodynamic loads. Although the blanket is very flexible during installation, its surface becomes hardened after application of the C-9 coating and brittle after thermal exposure.

Point of Contact:

  • Marc Rezin
  • NASA Ames Research Center
  • mrezin@mail.arc.nasa.gov

Pictures:

Properties at Standard Conditions
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Property Value Units Uncertainty Source STP Reference Last Modified Additional Data
Density1 6.00e+00 lbm/ft^3 1.50e+00 unknown assumed/assumed 4 2006-01-05
Additive Areal Weight2 3.00e-01 lbm/ft^2 N/A unknown assumed/assumed 2006-01-05
Thermal Conductivity (Thru-the-Thickness)3 5.28e-06 Btu/ft-s-R 2.63e-07 unknown TRUE 3 2006-01-05
Specific Heat 1.77e-01 Btu/lbm-R 8.86e-04 unknown TRUE 3 2006-01-05
Emissivity4 0.87 - 4.35e-02 unknown TRUE 1 2006-01-05
Multiple Use Temperature Limit5 1.66e+03 R 8.30e+01 measured assumed/assumed 4 2006-01-05
Single Use Temperature Limit6 1.96e+03 R 9.79e+01 measured assumed/assumed 4 2006-01-05
Purchase Cost7 3.30e+02 $/ft^2 1.65e+01 predicted assumed/assumed 2 2006-01-05
Installation Time8 2.20e+04 s/ft^2 1.10e+03 predicted assumed/assumed 2 2006-01-05
Inspection/Repair Time per Flight9 3.46e+03 s/ft^2 1.73e+02 predicted assumed/assumed 2 2006-01-05
Replacement Fraction per Flight10 1.80e-02 - 9.00e-04 predicted assumed/assumed 2 2006-01-05
Reuse Flight Limit (# of flights) 0.0 - N/A predicted assumed/assumed 2 2006-01-05

Notes:

  • 1. Value given is for the blanket batting (fill). Blanket bulk density varies with thickness. Bulk density = density (of Fill) + additive areal weight / thickness. AFRSI has a nominal thickness of 1.0 inch and a minimum and maximum shuttle demonstrated thickness of 0.24 and 1.94 inches respectively.
  • 2. Total areal weight = density * thickness + additive areal weight.
  • 3. Although this material's thermal conductivity depends on direction, only data for thermal conductivity normal to the plane of the blanket is available.
  • 4. Values for C-9 coated AFRSI blanket (with Astroquartz outer fabric).
  • 5. Source: "Shuttle Operational Data Book", Boeing.
  • 6. Source: "Shuttle Operational Data Book", Boeing.
  • 7. Cost for C-9 coated blanket.
  • 8. These values based on experience from NASA's Shuttle flights and may vary drastically if blanket environment changes from that of the Shuttle.
  • 9. These values based on experience from NASA's Shuttle flights and may vary drastically if blanket environment changes from that of the Shuttle.
  • 10. These values based on experience from NASA's Shuttle flights and may vary drastically if blanket environment changes from that of the Shuttle.

Property References:

  • 1. S. Amanda Chiu, William C. Pitts: Reusable Surface Insulations for Reentry Spacecraft:AIAA Paper 91-0695:Jan. 1991:TPSX Ref. #3.
  • 2. D.J. Rasky: Thermal Protection Systems for Future Reusable Launch Vehicles:25th International Conference on Environmemtal Systems, No. 951618:Jul. 1995:TPSX Ref. #7.
  • 3. anon: Materials Property Manual, Vol.3, Thermal Protection System Materials Data:Rockwell International Publication:Sep. 1980:TPSX Ref. #24.
  • 4. anon: Shuttle Operational Data Book:Boeing Document:Boeing:TPSX Ref. #28.

General References:

  • 1. S. Amanda Chiu, William C. Pitts: Reusable Surface Insulations for Reentry Spacecraft:AIAA Paper 91-0695:Jan. 1991:TPSX Ref. #3.
  • 2. D.J. Rasky: Thermal Protection Systems for Future Reusable Launch Vehicles:25th International Conference on Environmemtal Systems, No. 951618:Jul. 1995:TPSX Ref. #7.
  • 3. C. Ehrlich, et al.: Advanced Manned Launch System Study (AMLS); Reusable Cyrogenic Tank Design:Contract NAS1-18975 DRD-9:Rockwell International, Space Systems Division, Downey, CA:Jul.-Sep. 1993:TPSX Ref. #8.
  • 4. anon: Current Technology for Thermal Protection Systems:NASA Conf. Pub. 3157:Feb. 1992:TPSX Ref. #9.
  • 5. D.A. Kourtides, S.A. Chiu, D.J. Iverson, D.M. Lowe: Thermal Response of Rigid and Flexible Insulations and Reflective Coating in an Aeroconvective Heating Environment:NASA TM-103925:Mar. 1992:TPSX Ref. #26.
  • 6. D.A. Kourtides, J.L. Bandfield, N. Pakrasi, W.C. Pitts: Effect of Ceramic Coatings on Thermal Performance of Flexible Insulations:26th International SAMPE Technical Conference, Atlanta, GA:Oct. 24-27, 1994:TPSX Ref. #27.
  • 7. anon: Shuttle Operational Data Book:Boeing Document:Boeing:TPSX Ref. #28.