NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Development of Detectability Limits for On-Orbit Inspection of Space Shuttle Wing Leading EdgeAt the conclusion of the Columbia Accident Investigation, one of the recommendations of the Columbia Accident Investigation Board (CAIB) was that NASA develop and implement an inspection plan for the Reinforced Carbon-Carbon (RCC) system components of the Space Shuttle. To address these issues, a group of scientists and engineers at NASA Langley Research Center proposed the use of an IR camera to inspect the RCC. Any crack in an RCC panel changes the thermal resistance of the material in the direction perpendicular to the crack. The change in thermal resistance can be made visible by introducing a heat flow across the crack and using an IR camera to image the resulting surface temperature distribution. The temperature difference across the crack depends on the change in the thermal resistance, the length of the crack, the local thermal gradient, and the rate of radiation exchange with the environment. This paper describes how the authors derived the minimum thermal gradient detectability limits for a through crack in an RCC panel. This paper will also show, through the use of a transient, 3-dimensional, finite element model, that these minimum gradients naturally exist on-orbit. The results from the finite element model confirm that there are sufficient thermal gradient to detect a crack on 96% of the RCC leading edge.
Document ID
20050160201
Acquisition Source
Langley Research Center
Document Type
Preprint (Draft being sent to journal)
Authors
Stephan, Ryan A.
(NASA Langley Research Center Hampton, VA, United States)
Johnson, David G.
(NASA Langley Research Center Hampton, VA, United States)
Mastropietro, A. J.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Ancarrow, Walt C.
(WCA Enterprises Greenbelt, MD, United States)
Date Acquired
August 23, 2013
Publication Date
January 1, 2005
Subject Category
Quality Assurance And Reliability
Meeting Information
Meeting: SPIE Defense and Security Symposium 2005
Location: Orlando, FL
Country: United States
Start Date: March 28, 2005
End Date: April 1, 2005
Sponsors: International Society for Optical Engineering
Funding Number(s)
OTHER: 23-376-70-30-10
Distribution Limits
Public
Copyright
Public Use Permitted.
Document Inquiry

Available Downloads

There are no available downloads for this record.
No Preview Available