CHALLENGER

As part of its work, the commission conducted a postmortem. In medicine, a postmortem is an examination of a dead body to determine the root cause of death. As a metaphor, postmortem refers to any examination of a prior situation to understand what happened and how it could go better next time. At DuckDuckGo, it is mandatory to conduct a postmortem after every project so that the organization can collectively learn and become stronger (antifragile).


 One technique commonly used in postmortems is called 5 Whys, where you keep asking the question “Why did that happen?” until you reach the root causes. 1. Why did the Challenger’s hydrogen tank ignite? Hot gases were leaking from the solid rocket motor. 2. Why was hot gas leaking? A seal in the motor broke. 3. Why did the seal break? The O-ring that was supposed to protect the seal failed. 4. Why did the O-ring fail? It was used at a temperature outside its intended range. 5. Why was the O-ring used outside its temperature range? Because on launch day, the temperature was below freezing, at 29 degrees Fahrenheit. (Previously, the coldest launch had been at 53 degrees.) 6. Why did the launch go forward when it was so cold? Safety concerns were ignored at the launch meeting. 7. Why were safety concerns ignored? There was a lack of proper checks and balances at NASA. That was the root cause, the real reason the Challenger disaster occurred.