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Estimating Orion Heat Shield Failure Due To Ablator Cracking During The EFT-1 MissionThe Orion EFT-1 heatshield suffered from two major certification challenges: First, the mechanical properties used in design were not evident in the flight hardware and second, the flight article itself cracked during fabrication. The combination of these events motivated the Orion Program to pursue an engineering-level Probabilistic Risk Assessment (PRA) as part of heatshield certification rationale. The PRA provided loss of Mission (LOM) likelihoods considering the probability of a crack occurring during the mission and the likelihood of subsequent structure over-temperature. The methods and input data for the PRA are presented along with a discussion of the test data used to anchor the results. The Orion program accepted an EFT-1 Loss of Vehicle (LOV) risk of 1-in-160,000 due to in-mission Avcoat cracking based on the results of this analysis. Conservatisms in the result, along with future considerations for Exploration Missions (EM) are also addressed.

Document ID
Document Type
Conference Paper
Vander Kam, Jeremy C.
(NASA Ames Research Center Moffett Field, CA United States)
Gage, Peter
(Neerim Corp. Mountain View, CA, United States)
Date Acquired
June 15, 2016
Publication Date
June 13, 2016
Subject Category
Quality Assurance And Reliability
Spacecraft Design, Testing And Performance
Report/Patent Number
Meeting Information
Meeting: AIAA Thermophysics Conference
Location: Washington, DC
Country: United States
Start Date: June 13, 2016
End Date: June 17, 2016
Sponsors: American Inst. of Aeronautics and Astronautics
Distribution Limits
Public Use Permitted.
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