# Presentation: 519598

## Project PlanRoot Cause and Risk AnalysisTeam 2

- Project PlanRoot Cause and Risk AnalysisTeam 2

- NASA:  Henning Leidecker;  301-286-9180
- Boeing: Gary W. Bickel; 714-372-6820
- 3/20/00

## Team 2 Members

- Project Leads:		Henning Leidecker-NASA/GSFC
-                       Gary W. Bickel-Boeing/HB
- Team Members:	                     Ray Prestridge-JSC
-                 Pete Mueggler-BHB
-                 Carol McDonald-BHOU
-                 Anna Cantwell-SEA
-                 David Gill-BHB
-                 Jeanette Plante-GSFC
-                 Dave Rothermel-BICC
-                 Dale Zevotek-BICC
-                 Martin Seifert-LSFT
-                 David Beverly-JSC
-                 Craig Mueller-AERO
-                 Harold Battaglia-BHOU
-                 John Canham-GSFC

## Task 1-Root Cause Analysis

- Identify Primary Agent for “Rocket Engine Defect”--complete:  HF-etch enabled by Polyimide void and carbon coating breech
- Investigate Strength Reduction, ‘96 Cable--complete:  124/446 samples below Proof-Test level; Polyimide void consistently observed
- need to complete microphotographs on approximately 34 samples
- Investigate Strength Reduction, ‘98-9 Cable--partially complete
- Determine source of Polyimide coating voids (fiber or other process)
- Determine Agent (or process step) for carbon coating breech
- Resolve Lingering Questions (Polyimide Canyons versus voids, SEM)
- Complete Root Cause Analysis Report

## Task 1-Root Cause:  status

- Strength Tests 98-9 Cable-on hold; affects Truss
- Polyimide Coating Voids Source: pending coating penetration test results
- _1st Phase of Coating Penetration Test in Process_
- _Remainder of test plan under discussion_
- SEM to sort variations in Polyimide void structure: no progress pending completion of Coating Penetration Tests
- Root Cause Report:  Major sections left to write

## Task 2-Risk AnalysisUS Lab and Node 1

- Task 2-Risk AnalysisUS Lab and Node 1

- Estimate Potential Failures due to Rocket Engine Defects--
- Determine Effective “n” value--failed; insufficient data
- Determine alternate model for failure prediction of existing defects/flaws
- Estimate pre-flight and  on-orbit failures based on strength distribution data
- Determine Potential for Post-Process defect generation by Launch vibration impact
- Determine Potential for  on-orbit defect generation by Ionized Radiation
- Prepare Risk Analysis Report for US Lab and Node 1

## Task 2-Risk Analysis:  StatusUS Lab and Node 1

- Preliminary Risk Analysis Completed
- No consensus on Preliminary Risk Analysis based on “worst case” n-value
- Efforts on vibration/ionizing radiation launch & on-orbit effects on-going

## Task 3-Risk Analysis & Reduction(Node 1 DT0 Cable, ESA Cable, all ‘98-9 Cable Use)

- Task 3-Risk Analysis & Reduction(Node 1 DT0 Cable, ESA Cable, all ‘98-9 Cable Use)

- Determine Low Strength Distribution for ‘98-9 cable--
- Provide Preliminary Strength Tests on ESA Cable (representing ‘97 production)--
- Determine Effect of additional “Proof Testing” at the Cable level
- Apply results of above in estimating risk
- Prepare Risk Analysis Reports as needed for these tasks

## Task 3-Risk Analysis & Reduction:  Status(Node 1 DT0 Cable, ESA Cable, all ‘98-9 Cable Use)

- Strength Tests on 98-9 cable on hold
- Tests on ESA cable pending receipt of cables and funding decisions
- Proof Testing fixture in development

## Team 2--Schedule