Date of Award

2017-01-01

Degree Name

Doctor of Philosophy

Department

Material Science and Engineering

Advisor(s)

Stephen W. Stafford

Abstract

Since the end of the space shuttle program, a new generation spacecraft has been developed to transport humans back into space. NASAâ??s Orion will carry a crew beyond low-earth orbit and the exploration of Mars may be possible in the future. Space safety becomes significant with human spaceflight and the risks are high. However, aerospace materials may provide opportunities to prevent future disasters. When the space shuttle Columbia disintegrated during re-entry in 2001, thousands of debris were collected for analysis. In contrast, when the Challenger space shuttle broke apart in 1986, all shuttle debris were buried. These tragic disasters are reminders of the importance of proper material selection and the concern of their performance in service. This research focused on investigating the effects of the debris recovered from the Columbia space shuttle after re-entry and break-up. Many of the components encountered unforeseen extreme temperatures, vibrations, and high stresses. The Columbia debris contained unique characteristics that have yet to be examined and the components for this study are the thermal protection system (TPS) carrier panel tiles and the thermal pane glass from the starboard orbiter Window 7. The alterations endured by the debris was studied through forensic materials characterization to investigate material interactions, material degradation, and thermal consequences. These materials played an essential role in the operation of the orbiter as they protected the underlying structural materials of the shuttle and underwent extreme temperatures. The methods and procedures for analyzing the debris included non-destructive and destructive evaluations. Non-destructive evaluations involved visual inspection, photographic documentation, 3D modeling, and surface elemental composition. The destructive analysis consisted of sectioning, scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The results obtained revealed metallic and oxide formations, flow trajectory, and the presence of other space shuttle materials. Determining the conditions of the debris after break-up is valuable because new developments for future manned spacecraft will require TPS. These materials must be continued to be studied aggressively to provide risk assessment for future missions. The findings of this investigation will identify the alterations on the debris and determine if these TPS materials are reliable for future spacecraft.

Language

en

Provenance

Received from ProQuest

File Size

176 pages

File Format

application/pdf

Rights Holder

Brenda Roseanne Arellano

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