IN MEMORIAM

Report Volume I August 2003

¶On the Front Cover

This was the crew patch for STS-107. The central element of the patch was the microgravity symbol, µg, flowing into the rays of the Astronaut symbol. The orbital inclination was portrayed by the 39-degree angle of the Earthʼs horizon to the Astronaut symbol. The sunrise was representative of the numerous science experiments that were the dawn of a new era for continued microgravity research on the International Space Station and beyond. The breadth of science conducted on this mission had widespread benefits to life on Earth and the continued exploration of space, illustrated by the Earth and stars. The constellation Columba (the dove) was chosen to symbolize peace on Earth and the Space Shuttle Columbia. In addition, the seven stars represent the STS-107 crew members, as well as honoring the original Mercury 7 astronauts who paved the way to make research in space possible. The Israeli flag represented the first person from that country to fly on the Space Shuttle.

¶On the Back Cover

This emblem memorializes the three U.S. human space flight accidents – Apollo 1, Challenger, and Columbia. The words across the top translate to: "To The Stars, Despite Adversity – Always Explore"

¶Limited First Printing, August 2003, by the Columbia Accident Investigation Board

¶Subsequent Printing and Distribution by the National Aeronautics and Space Administration and the Government Printing Office Washington, D.C.

Rick D. Husband Commander

William C. McCool Pilot

Michael P. Anderson Payload Commander

David M. Brown Mission Specialist

Kalpana Chawla Mission Specialist

Laurel Blair Salton Clark Mission Specialist

Ilan Ramon Payload Specialist

Jules F. Mier, Jr. Debris Search Pilot

Charles Krenek Debris Search Aviation Specialist

This cause of exploration and discovery is not an option we choose; it is a desire written in the human heart … We find the best among us, send them forth into unmapped darkness, and pray they will return. They go in peace for all mankind, and all mankind is in their debt. – President George W. Bush, February 4, 2003

¶The quarter moon, photographed from Columbia on January 26, 2003, during the STS-107 mission.

VOLUME I In Memoriam — 3
Board Statement — 6
Executive Summary — 9
Report Synopsis — 11
PART ONE THE ACCIDENT Chapter 1 The Evolution of the Space Shuttle Program 1.1 Genesis of the Space Transportation System — 21
1.2 Merging Conflicting Interests — 22
1.3 Shuttle Development, Testing, and Qualification — 23
1.4 The Shuttle Becomes "Operational" — 23
1.5 The Challenger Accident — 24
1.6 Concluding Thoughts — 25
Chapter 2 Columbiaʼs Final Flight 2.1 Mission Objectives and Their Rationales — 27
2.2 Flight Preparation — 31
2.3 Launch Sequence — 32
2.4 On-Orbit Events — 35
2.5 Debris Strike Analysis and Requests for Imagery — 37
2.6 De-Orbit Burn and Re-Entry Events — 38
2.7 Events Immediately Following the Accident — 39
Chapter 3 Accident Analysis 3.1 The Physical Cause — 49
3.2 The External Tank and Foam — 50
3.3 Wing Leading Edge Structural Subsystem — 55
3.4 Image and Transport Analyses — 59
3.5 On-Orbit Debris Separation – The "Flight Day 2" Object — 62
3.6 De-Orbit/Re-Entry — 64
3.7 Debris Analysis — 73
3.8 Impact Analysis and Testing — 78
Chapter 4 Other Factors Considered 4.1 Fault Tree — 85
4.2 Remaining Factors — 86
PART TWO WHY THE ACCIDENT OCCURRED Chapter 5 From Challenger to Columbia 5.1 The Challenger Accident and its Aftermath — 99
5.2 The NASA Human Space Flight Culture — 101
5.3 An Agency Trying to Do Too Much With Too Little — 102
5.4 Turbulence in NASA Hits the Space Shuttle Program — 105
5.5 When to Replace the Space Shuttle? — 110
5.6 A Change in NASA Leadership — 115
5.7 The Return of Schedule Pressure — 116
5.8 Conclusion — 117
Chapter 6 Decision Making at NASA 6.1 A History of Foam Anomalies — 121
6.2 Schedule Pressure — 131
6.3 Decision-Making During the Flight of STS-107 — 140
6.4 Possibility of Rescue or Repair — 173
Chapter 7 The Accidentʼs Organizational Causes 7.1 Organizational Causes: Insights from History — 178
7.2 Organizational Causes: Insights from Theory — 180
7.3 Organizational Causes: Evaluating Best Safety Practices — 182

7.4 Organizational Causes: A Broken Safety Culture — 184
7.5 Organizational Causes: Impact of a Flawed Safety Culture on STS-107 — 189
7.6 Findings and Recommendations — 192
Chapter 8 History as Cause: Columbia and Challenger 8.1 Echoes of Challenger — 195
8.2 Failures of Foresight: Two Decision Histories and the Normalization of Deviance — 196
8.3 System Effects: The Impact of History and Politics on Risky Work — 197
8.4 Organization, Culture, and Unintended Consequences — 199
8.5 History as Cause: Two Accidents — 199
8.6 Changing NASAʼs Organizational System — 202
PART THREE A LOOK AHEAD Chapter 9 Implications for the Future of Human Space Flight 9.1 Near-Term: Return to Flight — 208
9.2 Mid-Term: Continuing to Fly — 208
9.3 Long-Term: Future Directions for the U.S. in Space — 209
Chapter 10 Other Significant Observations 10.1 Public Safety — 213
10.2 Crew Escape and Survival — 214
10.3 Shuttle Engineering Drawings and Closeout Photographs — 217
10.4 Industrial Safety and Quality Assurance — 217
10.5 Maintenance Documentation — 220
10.6 Orbiter Maintenance Down Period/Orbiter Major Modification — 220
10.7 Orbiter Corrosion — 221
10.8 Brittle Fracture of A-286 Bolts — 222
10.9 Hold-Down Post Cable Anomaly — 222
10.10 Solid Rocket Booster External Tank Attachment Ring — 223
10.11 Test Equipment Upgrades — 223
10.12 Leadership/Managerial Training — 223
Chapter 11 Recommendations — 225
PART FOUR APPENDICES Appendix A The Investigation — 231
Appendix B Board Member Biographies — 239
Appendix C Board Staff — 243

¶VOLUME II Appendix D CAIB Technical Documents Cited in the Report VOLUME III Appendix E Other Technical Documents Cited in the Report VOLUME IV Appendix F Other Technical Documents VOLUME V Appendix G Other Significant Documents VOLUME VI Appendix H Transcripts of Board Public Hearings