SPACECRAFT ACCIDENTS: EXAMINING THE PAST, IMPROVING THE FUTURE Overview and Challenger Case Study

1. SPACECRAFT ACCIDENTS:EXAMINING THE PAST, IMPROVING THE FUTUREOverview and Challenger Case Study Bryan Palaszewski working with the Digital Learning Network NASA Glenn Research Center

2. Introduction • Why discuss this subject? • Past failures • Learning from those failures • Observations

3. Why Discuss This Subject? • Many failures have occurred in large space projects, as well as all very complex projects. • Learning from our mistakes makes us smarter and more efficient, wasting less time and money, as well as possibly saving human lives.

4. Past Failures (1/4) • Early experiments (1920-1940’s) • Early big robotic rockets (1950’s and 1960’s) • Early human flights (1967, 1971) • Soyuz 1 (1 lost in flight, 1967) • Apollo 1 (3 lost in a ground test, 1967)

5. Past Failures (2/4) • Early human flights (continued) • Soyuz 11 (3 lost during reentry, 1971) • More-recent human flights • STS-51L, Challenger (7 persons lost, 1986) • STS-107, Columbia (7 persons lost, 2003)

6. Past Failures (3/4) • Many robotic missions have had accidents or failures • Tracking and Data Relay Satellite (TDRS-1, ground control enabled recovery, 1983) • INTELSAT-VI communication satellite (Space Shuttle Endeavour used for recovery, 1992)

7. Past Failures (4/4) • Many robotic missions have had accidents or failures (continued) • Mars Observer (lost, 1993) • Mars Climate Orbiter (lost, 1999) • Mars Polar Lander (crashed, 1999) • With each accident, an investigation is conducted to find the reason(s) for the failure. • Often there is a chain of incidents rather than just one cause.

8. Learning From Those Failures (1/2) • If a failure occurs, a major investigation committee is typically formed to find the cause. • Causes are identified (as with a detective) and solutions are suggested.

9. Learning From Those Failures (2/2) • Sharing information is critical to success. • Databases are created to teach those who follow what went wrong and how to prevent similar accidents in the future. • Investigation committee reports are part of the information gathering and sharing.

10. Observations • Communication is key to all successes. • Teams must understand one another to succeed. • Sharing information is critical to success. • “Teaching by doing” is important. • Hands-on work is very important.

11. Example Case Study STS-51L, Challenger Accident, January 28, 1986

13. Dark smoke from SRB leak

18. Accident Cause (1/2) • Launched while Solid Rocket Booster (SRB) was at a low temperature (about 32 degrees F) • At this low temperature, the rubber O-rings in the SRB were less soft and allowed escape of the hot gases from the booster (6000 degrees F).

19. Accident Cause (2/2) • A hot plume of gas was created, weakening the SRB metal attachments to the rest of the Shuttle. • Finally, the SRB broke the External Tank, which led to the destruction of the Space Shuttle.

20. Results of the Accident (1/5) • A Presidential Commission, including Neil Armstrong and Sally Ride, was formed to investigate the accident . • The Space Shuttle was grounded for 32 months. • Improvements were made to increase the sealing ability of the field joints where the leak of hot gases occurred.

21. Results of the Accident (2/5) • Heaters were added to the field joints to keep them warm. • And, many other improvements were made including: • Crew escape procedures • No commercial satellite flights • No civilians without specialized career astronaut training. • For many years, safer and higher reliability flights occurred.

22. Results of the Accident (3/5) • Many people lost their NASA positions including: • Lawrence B. Mulloy – project manager of the Solid Rocket Booster program at NASA Marshall Space Flight Center, Huntsville, Alabama • William R. Lucas, Center Director, NASA Marshall Space Flight Center, Huntsville, Alabama • William R. Graham, acting NASA Administrator, Washington, DC

23. Results of the Accident (4/5) • At Morton Thiokol, a private engineering firm, there were other effects: • Safety improvements were analyzed and created. • Many large-scale tests of the new SRB were conducted. • Roger Boisjoly, a program manager working on the SRB, had many problems (both mental and physical).

24. Results of the Accident (5/5) • Many other effects were noted throughout NASA: • Reductions of advanced propulsion research until safe flight was achieved. • Focus on near-term operational activities rather than more advanced thinking.

25. Thoughts of Roger Boisjoly (Morton Thiokol, 1/2) • The bench tests showed that temperature can adversely affect the resiliency and, therefore, the effectiveness of the O-rings. Yet management at Thiokol and NASA showed no interest in planning a design change.

26. Thoughts of Roger Boisjoly (Morton Thiokol, 2/2) • What general courses of action are reasonable for an engineer in this or a similar situation? • Consult personal advisors. • Gather knowledge of the problem. • Perform more experiments. • Consult peers at work. • Take concerns to a supervisor. • Write memos far up the corporate ladder. • Contact a professional society.

27. With advanced propulsion, one must always look to the past and look to the future.