Effective software is essential to the success and safety of the Space Shuttle, including its crew and its payloads. The on-board software continually monitors and controls critical systems throughout a Space Shuttle flight. At NASA's request, the committee convened to review the agency's flight software development processes and to recommend a number of ways those processes could be improved. This book, the result of the committee's study, evaluates the safety, oversight, and management functions that are implemented currently in the Space Shuttle program to ensure that the software is of the highest quality possible. Numerous recommendations are made regarding safety and management procedures, and a rationale is offered for continuing the Independent Verification and Validation effort that was instituted after the Challenger Accident. Table of Contents Front Matter Executive Summary 1. Overview of the Study 2. Independent Verification and Validation of Critical Software 3. The Space Shuttle Flight Software Development Process 4. The Space Shuttle Flight Software Verification and Validation Process 5. The Silent Safety Program Revisited 6. Organizational Issues 7. Final Thoughts and Future Considerations Biographical Sketches of Committee Members Bibliography Appendix A: Study Participants Appendix B: Statement of Task Appendix C: Interim Report of the Committee for Review of Oversight Mechanisms for Space Shuttle Flight Software Process: Independent Verification and Validation for Space Shuttle Flight Software Appendix D: Overview of ASET IV & V Methodology Appendix E: Flight Software Verification and Validation Requirements