January 28, 2016 was the 30th anniversary of the Challenger disaster when the space shuttle Challenger exploded 73 seconds into take off killing all seven crew members. It remains one of NASA’s darkest days and has profound lessons for risk management that still ring true today.
NASA astronaut Leroy Chiao, who flew three space shuttle missions during his career (in 1994, 1996 and 2000) described the accident this way at Space.com – https://www.space.com/31760-space-shuttle-challenger-disaster-30-years.html
“There was a ‘launch fever’ at the time, to try to get these missions off on time, and get more missions going,” he said.
That type of thinking played a significant role in the disaster, experts have concluded. Challenger was lost because a rubber “O-ring” seal on the shuttle’s right-hand solid rocket booster failed, allowing hot gas to escape and damage the orbiter’s external fuel tank, as well as the gear that attached the booster to the tank. [The O-ring on the shuttle serves a similar purpose as the O-rings on MSR Whisperlite stoves which prevent fuel from escaping the stove pump.]
The O-ring failed in part because unusually cold temperatures on launch day caused the part to harden, investigators later determined. The temperature at liftoff time was 36 degrees Fahrenheit (2 degrees Celsius) — 15 degrees F (8 degrees C) colder than any previous shuttle launch, NASA officials have said.
“The decision to launch the Challenger was flawed. Those who made that decision were unaware of the recent history of problems concerning the O-rings and the joint, and were unaware of the initial written recommendation of the contractor advising against the launch at temperatures below 53 degrees Fahrenheit [11.7 degrees C] and the continuing opposition of the engineers at Thiokol [Morton Thiokol, which built the shuttle’s solid rocket boosters] after the management reversed its position,” investigators wrote in their report about the disaster, which is known as the Rogers Commission Report.
“They did not have a clear understanding of Rockwell’s concern that it was not safe to launch because of ice on the pad,” they added. (Rockwell International built the space shuttles for NASA.) “If the decision-makers had known all of the facts, it is highly unlikely that they would have decided to launch 51L on Jan. 28, 1986.”
The Risk Assessment and Safety Management Model (RASM)
RASM is very useful model for assessing and mitigating risk as part of your overall risk management program. RASM describes the impact of Hazard Factors on increasing levels of risk and how removing individual Hazard Factors and/or adding Safety Factors will help you proactively manage risk in your organization. The graphic below illustrates the modeland you can read more about the model at Risk Assessment & Safety Management Model (RASM)
Analyzing the Challenger Accident
The Risk Assessment & Safety Management Model (RASM) provides a model of evaluating the hazards that led to the Challenger disaster. While the reports such as the Roger’s Report issued after the accident are hundreds of pages long, we can focus on several critical facts that led to the accident.
- The cold temperatures (38 degrees F) the morning of the launch.
- The O-rings were rubber rings designed to form a seal in the shuttle’s solid rocket boosters, preventing the rockets’ hot gas from escaping and damaging other parts of the vehicle. These O-rings designed for higher temperatures and it had been a concern for some time that under very cold temperatures the O-rings could fail. The O-rings had been designated a “Criticality 1″ item by NASA, meaning it was a component without a backup. Any failure in this component would result in the loss of the shuttle and its crew.
Human Factor Hazards
- “The Committee found that NASA’s drive to achieve a launch schedule of 24 flights per year created pressure throughout the agency that directly contributed to unsafe launch operations. The Committee believes that the pressure to push for an unrealistic number of flights continues to exist in some sectors of NASA and jeopardizes the promotion of a “safety first” attitude throughout the Shuttle program.” 1. The Roger’s Report
- “The Committee, the Congress, and the Administration have played a contributing role in creating this pressure. Congressional and Administration policy and posture indicated that a reliable flight schedule with internationally competitive flight costs was a near-term objective. Pressures within NASA to attempt to evolve from an R&D agency into a quasicompetitive business operation caused a realignment of priorities in the direction of productivity at the cost of safety.” 2. The Roger’s Report
In order to assess your program, examine your operational systems and determine if you have any “Criticality 1” systems. What would the impact be if that system failed? What would that mean for your entire organization?
The Rogers Report – https://www.gpo.gov/fdsys/pkg/GPO-CRPT-99hrpt1016/pdf/GPO-CRPT-99hrpt1016.pdf
Missed Warnings: The Fatal Flaws Which Doomed Challenger – https://www.spacesafetymagazine.com/space-disasters/challenger-disaster/missed-warnings-fatal-flaws-doomed-challenger/
Space Shuttle Challenger disaster – https://en.wikipedia.org/wiki/Space_Shuttle_Challenger_disaster