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					 Review of Test Data Indicates Conservatism for Tile
                    Penetration
• The existing SOFI on tile test data used to create Crater
  was reviewed along with STS-87 Southwest Research data
   – Crater overpredicted penetration of tile coating
     significantly
       • Initial penetration to described by normal velocity
           – Varies with volume/mass of projectile (e.g., 200ft/sec for
             3cu. In)
       • Significant energy is required for the softer SOFI particle
         to penetrate the relatively hard tile coating
           – Test results do show that it is possible at sufficient mass
             and velocity
       • Conversely, once tile is penetrated SOFI can cause
         significant damage
           – Minor variations in total energy (above penetration level)
             can cause significant tile damage
   – Flight Condition is significantly outside of test database
       • Volume of ramp is 1920cu in vs 3 cu in for test

                                                                           6
Recommend Immediate Visual Inspection of Columbia

• The Crater software can not predict damage to
  Columbia because the foam piece that hit the ship
  was big and was travelling very quickly.
• Even tiny foam particles can penetrate the tiles when
  they strike with sufficient velocity.
   – Once tiles are penetrated, significant damage to the
     spacecraft is possible.
• The foam piece that hit Columbia was 600 times
  bigger than the foam used to calibrate Crater.
   – 1920 in3 vs. 3 in3 for test.
• Therefore, as a predictor, Crater is useless in this
  case.


                                                            6
Recommend Immediate Visual Inspection of Columbia

   The Crater software can not predict damage to Columbia
    because the foam piece that hit the ship was big and was
    travelling very quickly.
   Even tiny foam particles can penetrate the tiles when they
    strike with sufficient velocity.
      ◦ Once tiles are penetrated, significant damage to the spacecraft is
        possible.
     The foam piece that hit Columbia was 600 times bigger
      than the foam used to calibrate Crater.
      ◦ 1920 in3 vs. 3 in3 for test.
     Therefore, as a predictor, Crater is useless in this case.




                                                                             6
   The Crater software can not predict damage to
    Columbia because the foam piece that hit the
    ship was big and was travelling very quickly.
   Even tiny foam particles can penetrate the tiles
    when they strike with sufficient velocity.
    ◦ Once tiles are penetrated, significant damage to the
      spacecraft is possible.
   The foam piece that hit Columbia was 600 times
    bigger than the foam used to calibrate Crater.
    ◦ 1920 in3 vs. 3 in3 for test.
   Therefore, as a predictor, Crater is useless in
    this case.



                                                             6
RECOMMEND IMMEDIATE VISUAL INSPECTION OF COLUMBIA

  The Crater software can not predict damage to
   Columbia because the foam piece that hit the ship
   was big and was travelling very quickly.
  Even tiny foam particles can penetrate the tiles
   when they strike with sufficient velocity.
        Once tiles are penetrated, significant damage to the
         spacecraft is possible.
    The foam piece that hit Columbia was 600 times
     bigger than the foam used to calibrate Crater.
        1920 in3 vs. 3 in3 for test.
    Therefore, as a predictor, Crater is useless in this
     case.

                                                                6
                                                                        6
Recommend Immediate Visual Inspection of Columbia

  • The Crater software can not predict damage to
    Columbia because the foam piece that hit the ship was
    big and was travelling very quickly.
  • Even tiny foam particles can penetrate the tiles when
    they strike with sufficient velocity.
    ▫ Once tiles are penetrated, significant damage to the spacecraft
      is possible.
  • The foam piece that hit Columbia was 600 times
    bigger than the foam used to calibrate Crater.
    ▫ 1920 in3 vs. 3 in3 for test.
  • Therefore, as a predictor, Crater is useless in this case.
Recommend Immediate Visual Inspection of Columbia


   The Crater software can not predict damage to Columbia
    because the foam piece that hit the ship was big and was
    travelling very quickly.
   Even tiny foam particles can penetrate the tiles when
    they strike with sufficient velocity.
      Once tiles are penetrated, significant damage to the spacecraft is
        possible.
   The foam piece that hit Columbia was 600 times bigger
    than the foam used to calibrate Crater.
      1920 in3 vs. 3 in3 for test.
   Therefore, as a predictor, Crater is useless in this case.




                                                                            6
 The Crater software can not predict damage to
  Columbia because the foam piece that hit the
  ship was big and was travelling very quickly.
 Even tiny foam particles can penetrate the tiles
  when they strike with sufficient velocity.
    › Once tiles are penetrated, significant damage to the
      spacecraft is possible.
   The foam piece that hit Columbia was 600 times
    bigger than the foam used to calibrate Crater.
    › 1920 in3 vs. 3 in3 for test.
   Therefore, as a predictor, Crater is useless in this
    case.



                                                      6
Recommend Immediate Visual Inspection of Columbia

   The Crater software can not predict damage to
    Columbia because the foam piece that hit the ship
    was big and was travelling very quickly.
   Even tiny foam particles can penetrate the tiles when
    they strike with sufficient velocity.
       Once tiles are penetrated, significant damage to the
        spacecraft is possible.
     The foam piece that hit Columbia was 600 times
      bigger than the foam used to calibrate Crater.
       1920 in3 vs. 3 in3 for test.
     Therefore, as a predictor, Crater is useless in this
      case.



                                                               6
Recommend Immediate Visual Inspection of Columbia

Sample damage from a very small   Size of foam that hit Columbia is
foam hit                          600 times bigger




                                                                      6
Recommend Immediate Visual Inspection of Columbia

Sample damage from a very small   Size of foam that hit Columbia is
foam hit                          600 times bigger




                                                                      6
Recommend Immediate Visual Inspection of Columbia
Recommend Immediate Visual Inspection of Columbia


     Sample damage
     from a very small
     “dime size” foam hit




                               Size of foam that hit
                               Columbia is 600 times
                               bigger



                                                       6
Recommend Immediate Visual Inspection of Columbia
Recommend Immediate Visual Inspection of Columbia


     Sample damage
     from a very small
     “dime size” foam hit




                               Size of foam that hit
                               Columbia is 600 times
                               bigger



                                                       6
Recommend Immediate Visual Inspection of Columbia
Recommend Immediate Visual Inspection of Columbia


     Sample damage
     from a very small
     “dime size” foam hit




                               Size of foam that hit
                               Columbia is 600 times
                               bigger



                                                       6
Need to Inspect Columbia!


The Crater software can not
predict damage to Columbia




                          The foam piece that hit Columbia
                          was 600 times bigger than the
                          foam hits used to calibrate Crater.




                                                                6
Need to Inspect Columbia!


The Crater software can not
predict damage to Columbia




                          The foam piece that hit Columbia
                          was 600 times bigger than the
                          foam hits used to calibrate Crater.




                                                                6
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posted:11/25/2011
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