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5A AOE-0588 SSQ 21654 Fiber Optic Cable Anomaly - Tiger Team Meeting

5A AOE-0588 SSQ 21654 Fiber Optic Cable Anomaly - Tiger Team Meeting. Boeing - EEE Parts. David Gill (714) 896-6403. 12/8/99. Early FO Cable Disposition Plan.

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5A AOE-0588 SSQ 21654 Fiber Optic Cable Anomaly - Tiger Team Meeting

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  1. 5A AOE-0588 SSQ 21654 Fiber Optic Cable Anomaly - Tiger Team Meeting Boeing - EEE Parts David Gill (714) 896-6403 12/8/99

  2. Early FO Cable Disposition Plan • Focus of team has been working on the root cause as well as gathering enough empirical evidence to clear early cable (Shipped during 1995-1997) • Early cable represents hardware which has been installed on Node 1, US Lab, Airlock, S0, and ORUs • FO TIM Early Cable “Bubble” Disposition Plan • Obtain as much cable from similar dates of manufacture to determine if the bubbles existed and if they would lead to failure. Rationale for use could then be supported by data • Identified 9600’ of cable at SEA Wire and cable • Identified 1000 feet of APS test harness cable • 16 US Lab MSS Rack Links • 6 failed links; 3 from MSS Racks and 3 from US Lab • Investigate other programs usage, application, and experience with same optical fiber

  3. Early FO Cable Bubble Disposition Rationale • Similar amounts of similar vintage cable (1996) has been tested using a proven bubble detection method (~ 11,000’ tested vs. ~14,000’ Installed) • 1 bubble found which is detectable using current acceptance test techniques • 16 US Lab MSS Rack flight links + additional test sets cables tested without detecting a single bubble • NASA-Goddard tested 1000+’ of the same fiber (different jacketing) from similar lots and did not detect a single bubble • Installed cables have been through handling during manufacturing build-up and installation and testing • 6/17 failures have been analyzed and determined to have failed due to mechanical overstress as a result of handling. Others were not analyzed. • Failure rate during installation (~2%) similar for current elements on ISS experience • 700+ flight FO links have passed optical loss ATP both at assembly and post installation without a detected bubble • 3 years has expired on the early production cables • Zero ORU fiber optic cable failures once ORU has passed post installation ATP • Bubble rate of later fiber optic cable builds indicate significant differences between early cable and recent • At least two changes in the production process have been noted during the investigation to date

  4. Node 1, US Lab, Airlock and Early ORUs Bubble Disposition Plan Developed during FO Summit Review HVL Build/Shipping Records Locate HVL Early Manufactured SSQ 21654 Cable Review SEA Shipping History 10-24 10-18 Test Using High Power Laser Screen Review HB Build/Shipping Records Locate HB Early Manufactured SSQ 21654 Cable 11-13-99 Review BICC/Spectran Build History Destructive Tensile Testing of Limited Number of Samples 10-24 11-4-99 10-15 Test for Optical Loss Using OTDR/RIFOCs Techniques 11-16-99 Develop Statistical Model to Define Confidence in Not Screening US Lab Cables 11-16-99 2nd Round of CER 11/24/99 Determine Statistical Confidence of bubble(s) in early elements and ORUs 10-29-99 Present Analysis To ISS Chief Engineers Remove/Ship US Lab W/H Failures @ KSC 11-16-99 11-18-99 11-3 Perform F/A of Samples 11-10 Present Analysis To ISS Program Understand the degradation of Optical Loss and Strength Phenomena Remove/Ship MSS Rack W/H Failures @ HVL 11-19-99 11-8 Test MSS Rack W/H using Laser @ HVL 12-15-99 11-29-99 11-3

  5. Early FO Cable Bubble Disposition Rationale Conclusion • High confidence has been developed by testing limited numbers of flight links, similar vintage cable on both reels and in test set applications, and analyzing limited numbers of failed flight links • Statistical Confidence > 99.5%has been reached • Node 1, US Lab, Airlock, S0, and early ORUs hardware does NOT contain any bubble defects • Residual Issues • Optical Degradation • Spools retested - Closed - Testing Error • Losses decreased post respooling • Causes of high losses determined to improper spooling practices • Mechanical strength and optical degradation • Testing in progress

  6. FO Cable Root Cause Investigation Plan • Investigating probable cause(s) identified in the fault tree • Perform Audits and discussions with supplier’s build records to analyze six unique builds over the last three years • Initiate in-line process inspections and tests of new product as it is being manufactured • Restart the production line and monitor

  7. Root Cause Investigation Plan Obtain Raw Fiber Experimentation of Fiber Susceptability Data Search/ Analyze Contributing Applications/Factors Emphasis on ESD Effects 1-10 Early Cable Re-evaluation (See US Lab Disposition Test at Contributing Processes Steps Develop Test Setup SEA Build Record Review 11-24 1-20 11-17 Process Variations not Controlled 12-15 BICC Build Record Review Selected Experts Product History Audit Audit Findings 11-19 Personnel Changes Monitor Restart of Production Line (See Restart Production Line) 12-20 Process Changes Spectran Build Record Review 12-3 Baseline Samples for future evaluation HB Impound Stock Testing Cut Samples Scrapped to Engineering Quantify Loss/ Non-destructive Optical Testing 3-10-00 Tensile Testing/Glass&Jacket Sectioning/Coating Removal/Other Chemical Analysis Techniques Deliver to NASA-Goddard/ Bell Labs 1-15 Parallel Investigation 1-20 Optical/SEM & Other Evaluation Identify Analysis Techniques Laser Power Damages Fiber Identify Sources Used 1-30 Experimental Testing Review Data & Analyze 1-31 Determine Field Experience Monitor Other Programs Determine Program Test/Inspection Criteria Determine Root Cause/ Most Probable Cause(s) 3-20-00 Update SCAN with Closout Actions 3-31-00

  8. High Optical Losses in FO Cables 5A AOE-0588 SSQ 21654 Fiber Optic Cable Anomaly Fault Tree W/H Testing or Mating H/W Error(s) Fiber Optic Cable Design/Manufacturing Error(s) Wire Harness Assembly Tools/Procedure Error(s) FO W/H Design Error(s) Shipping/storage Exposes Cables to High Energy Too Much energy is concentrated at fiber weak point Glass Fiber ManufacturingError(s) Preform/Fiber design Changes FO Cable Jacketing Error(s) Cladding IDSurface not properly prepared FO Cable Testing Error(s) Cladding Material/Supplier or Dimensional Change Outside Jacket Applied too thick Degreasing Material/Process Changes Spectran Improperly Performs testing BICCGeneral Improperly Performs testing Core Material/Supplier or Index Dimensional Changes Outside Jacket Applied with Too Much Heat Initial cladding processing personnel error(s) Testing Performed inadequate Pre-form Processing shrinks material too slow/fast Outside Jacket Applied Too Much Speed Imperfections in ID Fiber laser mic generates sufficient ESD energy Test Method/Procedure Unable to detect all anomalies Pre-form Lathe Processing temperatures not controlled properly Strength Member Too Many Braids Etch materials/.process changes Buffer Tube too Small Strength Member Too Few Braids Buffer Tube too Large Cladding wash material/ process change Pre-form Lathe rotation too slow/fast Buffer Tube not round enough Strength Member not Proper Material Core material not properly processed Index Scrubbing Process improperly implemented Prejacket fiber wheels Damage Coatings Index Step Materials Contamination Preform processing personnel error(s) Buffer Tube not Proper Material Fiber Draw Failure Modes Index processing personnel changes Personnel in tower causes error(s) Drawing tower temperature/speed not controlled Prejacket fiber wheels Damage Coatings Creation of micro gas bubble Index Lathe Processing temperatures not controlled properly Index Step Materials Improperly Applied Tensile test mandrels not performing properly Drawing tower furnace too hot/cold Fiber Coating Material/ Process changes Drawing tower speed too slow/fast Index Lathe rotation too slow/fast Carbon Coating Material/Process variations Polyamide Coating Material/Process variations Drawing tower start/stops or speed not smooth Contamination in Tower Index processing personnel error(s)

  9. SSQ 21654 Suppliers Production Restart Plan Restart Production Line Plan Identify & Procure Forward Requirements 11-5-99 12-10-99 Manufacture Preforms and Test 1-5-00 Audit Six Unique Fiber Lots from Materials to Delivery at SEA/BICC/Spectran Fiber Draw and Test 2-25-00 12-15 Manufacture Cable Jacket and Test 3-10-00 Implement lessons learned into production in-line process verification Recommend New In-line Inspection/Test Process Requirement(s) Receiving Inspection and Test @ Boeing 12-31-99 12-15-99 3-20-00 Generated SSQ Change Language Present to Boeing/NASA Boards for Approval 1-15-00 1-31-99

  10. FO Wire Harnesses ITCE Forward Plan Procure/Recieve Ground Test Cable/Part Requirements Manufacture/Test Ground Support Harnesses For All ITCEs Develop Ground Test Alternative Design 12-10-99 1- 30-00 6- 30-00 Assess Current Production Status Disposition using Early Cable Disposition S0 Test S0 using current ATP Test Methods and Techniques 12-15-99 11-10-99 3-15-00 Decide Best Retest/Remanfacturing Plan Repair, as required, using best design/manufacturing/test approach 1-31-00 4-15-00 S1/P1, S3/P3 Rebuild Harness by Removing existing FO Cable Develop Design Standard Repair Drawings Develop Retest/Remanufacturing Trade Options 2-15-00 12-31-99 12-31-99 Repair Harness by Overlay All/Partial FO Cable then Beta Cloth Re-manufacture and ATP W/Hs Test Using RIFOCs 12-31-99 5-15-00 12-31-99 Re-screen Cables 3-10-00 Repair Harness by Overlay All Cable and apply Convoluted Tube Concept Remove Harnesses From Vehicle/Beta Cloth and Test using Laser Re-install and Post Installation ATP W/Hs 12-31-99 5-30-00 12-31-99 Retest Harnesses In-place Using OTDR or other Suitable Method 12-31-99

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