Download
1 / 10
100 likes | 212 Vues
This report outlines the collaborative efforts of NASA and Boeing in analyzing root causes and risks associated with rocket engine defects. Led by Henning Leidecker from NASA and Gary W. Bickel from Boeing, the team of experts addressed critical issues such as polyimide coating voids and carbon coating breaches. The analysis covers quality deterioration indicators, potential failure predictions, and identifies gaps in data. Key tasks include completing strength tests and preparing risk analysis reports for future projects. Ongoing discussions and proposals aim to enhance pre-flight and orbital reliability.
E N D
Project PlanRoot Cause and Risk AnalysisTeam 2 NASA: Henning Leidecker; 301-286-9180 Boeing: Gary W. Bickel; 714-372-6820 2/25/00
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 • Microphotos on 34 Samples-deferred • Strength Tests 98-9 Cable-on hold • Polyimide Coating Voids Source: no progress • Coating Penetration Test Plan in development • SEM to sort variations in Polyimide void structure: no progress • Root Cause Report: Major sections left to write
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: StatusUS Lab and Node 1 • Preliminary Risk Analysis Completed • No consensus on Preliminary Risk Analysis based on “worst case” n-value • Preparing proposal to do n-value tests for ESD attack on uncabled fiber • 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) • 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
