Engineer Who Tried to Stop Challenger Launch Dies

Allan McDonald warned that O-rings could fail
By Rob Quinn,  Newser Staff
Posted Mar 10, 2021 3:34 PM CST
Engineer Who Tried to Stop Challenger Launch Dies
"II refused to sign it," McDonald said. "I just thought we were taking risks we shouldn't be taking."   (NASA)

Allan McDonald, the engineer who refused to approve the launch of the space shuttle Challenger, has gone to his grave with a clean conscience. McDonald. the engineer in charge of the booster-rocket program at NASA contractor Morton Thiokol, risked his career by resisting pressure from NASA and his bosses to approve the launch. He warned that freezing overnight temperatures could compromise the O-ring gaskets at the booster rocket joints. "If anything happens to this launch, I wouldn't want to be the person that has to stand in front of a board of inquiry to explain why we launched," he recalled saying on Jan. 27, 1986. He was overruled by his supervisor, who signed the approval form. An O-ring failure caused the space shuttle to explode 72 seconds after the launch the next morning, killing all seven crew members.

Relative say McDonald, 83, died Saturday from complications from a fall at his Utah home, the New York Times reports. Mark Maier, director of a documentary about McDonald's decision, tells NPR he was a hero both for trying to halt the launch and for exposing NASA's attempts to cover up the facts. Morton Thiokol demoted him after he told the presidential commission investigating the disaster that the launch was only approved after execs, under pressure from NASA, overruled engineers. After Congress objected, he was reinstated and put in charge of redesigning the booster rocket. After his retirement, he held ethics seminars for engineers. Maier says he stressed his "laws of the seven R's." "It was always, always do the right thing for the right reason at the right time with the right people," and "you will have no regrets for the rest of your life," Maier says. (More Space Shuttle Challenger stories.)

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