Date: Wednesday, March 17, 2004
Location: Ballroom B, Charlotte Convention Center
Richard W. Russell, United Space Alliance, Materials & Processes Engineering, Kennedy Space Center, Florida
Building upon an article in the February 2004 issue of JOM, “Materials Analysis: A Key to Unlocking the Mystery of the Columbia Tragedy,” by Brian M. Mayeaux et al., the authors describe their investigation of the Columbia remains. The authors/presenters are members of the Materials and Processes team assembled by NASA to analyze the debris. Among the team’s tasks were the cleaning, field assessment, non-destructive inspection, sampling and analysis, and failure analysis of the recovered shuttle materials.
The following papers will be presented:
“The Materials and Processes Team Role in Columbia's Recovery, Reconstruction and Analysis”: Rick Russell, United Space Alliance, Kennedy Space Center, Florida
An overview of the Columbia investigation, starting from recovery of debris items through the reconstruction and analysis at Kennedy Space Center, will be presented. The Materials and Processes (M&P) team's role, including cleaning, field assessment, non-destructive inspection, sampling and analysis, and failure analysis will be discussed.
“Fracture of Aluminum Structural Materials”: Robert Piascik and Stephen Smith
During the Columbia reconstruction effort, a delamination fracture mode was observed on much of the orbiter aluminum structure debris. The delamination fracture is characterized by a fiber-like fracture mode similar to that observed in polymer matrix composite fracture. During the Columbia reconstruction effort, the unusual fracture mode was descriptively termed as a "broom straw looking failure." A detailed metallographic study was conducted to understand this first-of-a-kind fracture mode. The aim of this study was to understand this failure mode relative to the high-speed break-up of the orbiter during re-entry.
“Failure Analysis of A286 Carrier Panel Fasteners”: Tom Collins and Rick Russell
During field assessment it was noted that several A286 carrier panel fasteners had what appeared to be a brittle fracture mode. Results of failure analysis, including chemical, fractographic, metallographic, and exemplar testing will be presented.
“Analytical Tools and Techniques”: Steve McDanels
Several methods of chemical analysis were performed to determine the most useful in understanding the slag's depositional characteristics. Techniques included: scanning electron microscopy/energy dispersive spectroscopy, electron spectroscopy for chemical analysis, x-ray diffraction, and electron microprobe analysis. The relative merits and drawbacks of each technique will be explored.
“Wing Leading Edge Debris Analysis”: Sandeep Shah and Greg Jerman
Having selected the reinforced carbon-carbon (RCC) wing leading edge debris sample analysis techniques, guided by radiography, focused sampling with RCC intact was done to identify the content, layering, and if possible, hardware of origin. Analysis and interpretation of this data across the wing leading edge was hoped to answer the high-level questions of where did the breach occur? What was the sequence of melting? And, finally, what was the plasma flow direction? Two samples of each feature were taken and emphasis was placed on reproducibility and repeatability. The techniques used were metallography for cross-section analysis, scanning electron microscopy for imaging and x-ray mapping, electron microprobe analysis for pinpoint accurate chemical analysis, and x-ray diffraction to identify compounds. The data obtained was able to provide a picture of what happened, consistent with the leading failure scenario based on visual observations.
“Failure Analysis Integration: The Materials and Processes Team's Role in the Overall Investigation and Conclusions”: Brian Mayeaux, Julie Kramer-White, Rick Russell
The Materials and Processes team's observations and results are compared and integrated with the findings and conclusions of the reconstruction team, and melded into the overall investigation.