1. The Challenger Disaster
Risk Management
Jameson Smieja
Andrew Tilstra
Kurt Butz
William Schaffer

2. The art and science of identifying, analyzing, and responding to risk
Risk Management
The art and science of identifying, analyzing, and responding to risk

3. The Challenger Mission 51L
10th mission for the Challenger Shuttle
TISP – Teachers In Space Program
Christa McAuliffe
Politically Charged Launch
Christa was to appear via television link during Reagan’s State of the Union Address in 1986

4. Challenger Delays Liftoff: 11:38 EST January 28, 1986
Liftoff Initially Scheduled for 15:43 EST on Jan. 22, 1986
Delays in 61-C mission pushed liftoff to Jan. 23, then Jan. 24
Reset to Jan. 25 due to weather
Postponed another day due to launch processing problems
Rescheduled for 9:37 EST Jan. 27 due to weather
Delayed again due to equipment failure for 24 hours
Final 2 hour delay due to hardware interface module problems
Liftoff: 11:38 EST January 28, 1986

5. The Challenger Disaster
73 Seconds After Liftoff

6. What Went Wrong??
Failure of an “O-ring” seal in the solid-fuel rocket on the Space Shuttle Challenger's right side
Flames cut into main liquid fuel tank

7. Four Main Causes of O-Ring Failure
Pre-flight Leak Tests
O-Ring Erosions
Joint Rotation
Low Temperatures

8. Poor Risk Management Risks were managed using Critical Items Lists
Criticality 1-Loss of Life or Ship
Criticality 2-Mission Aborted
CIL Flaws
Unreliable
In previous missions, criticality1 issues occurred but loss of life/ship did not
Negotiable
Identified risks could later be waived

9. Known Potential Problems
O-rings were “Criticality 1” feature
O-ring seal failure on previous missions
Launch Constraint placed on subsequent launches
These constraints had been imposed and regularly waived by the SRB Project Manager

10. Known Potential Problems
Very low ambient temperatures recognized as concern by Tiokol
O-ring performance at this temperature not understood
NASA officials pressured Tiokol to withdraw its concerns
Upper officials at NASA were unaware of these discussions and ignorantly approved launch

11. References
“Space Shuttle Challenger 1986” ( (1996)
“Space Shuttle Challenger Disaster-A NASA Tragedy” (
“Expert Panel Recommends Improvements for Space Shuttle Safety Program”, ( (March 3, 1988)
“An Accident Rooted In History” ( (June 6, 1986)
“The Challenger Accident” ( (1997)