The 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.
Estimating Orion Heat Shield Failure Due To Ablator Cracking During The EFT-1 Mission
2016
12 pages
Report
No indication
English
Quality Control & Reliability , Unmanned Spacecraft , Manned Spacecraft , Heat shielding , Ablative materials , Crack initiation , Thermal protection , Crew exploration vehicle , Probability theory , Risk assessment , Mechanical properties , Reliability engineering , Honeycomb structures , Structural reliability , Structural failure , Failure analysis
Computational Study of Impregnated Ablator for Improved Magnetohydrodynamic Heat Shield
Online Contents | 2013
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