[Interview] Alan MacDonald, an engineer who accused NASA of concealment in the Challenger explosion, died
In 1986, the Space Shuttle Challenger was disassembled in the air immediately after its launch, killing all seven crew members in the '
Allan McDonald, Who Refused To Approve Shuttle Challenger Launch, Dead At 83: NPR
https://www.npr.org/2021/03/07/974534021/remembering-allan-mcdonald-he-refused-to-approve-challenger-launch-exposed-cover
Launched from the Kennedy Space Center in Florida on January 28, 1986, the Challenger disassembled in the air 78 seconds after launch. You can see the moment of the Challenger's aerial disassembly, which attracted a lot of attention as a major accident that shakes the United States, from the following movie.
Space shuttle Challenger exploding during launch --YouTube
Subsequent analysis revealed that the direct cause of the accident was ' damaged O-rings on the Solid Rocket (SRB) mounted on the Space Shuttle.' The O-ring to prevent fuel leakage lost its elasticity and was damaged, and the airtightness was impaired. As a result, high-pressure and high-temperature gas leaked from the SRB immediately after launch, causing structural collapse in various places. That led to the aerial disassembly of the Challenger.
A team of engineers, including McDonald, who was the chief engineer of the rocket manufacturer Morton-Siocol (now ATK Ranch Systems ), who was in charge of designing and manufacturing the SRB, said, 'O-rings are airtight when the temperature is below 12 ° C. I can't say that it has enough elasticity to maintain its sexuality. ' I strongly opposed the launch, expecting that the elasticity of the O-ring would definitely be lost if the SBR cooled down the night before the launch.
Below is a photo of the launch pad taken early in the morning of the launch day. As expected by engineers, the launch was frozen at sub-zero temperatures, the Space Shuttle was frosted, and the railings of the launch were icicles.
McDonald's refused to sign the documents authorizing the launch and submitted to NASA a written statement in collaboration with a team of engineers that temperatures should not be below 12 ° C. However, NASA officials claimed that there was no problem with the launch of the Space Shuttle so far, and that there was a lack of data indicating that the O-ring was damaged. Judging that the space shuttle is extremely safe, we ignored the opinion of the team of engineers.
At the time of the accident, NASA was criticized for lack of transparency because it was reluctant to disclose information. And because NASA's own accident investigation is unreliable, the 'Space Shuttle Challenger Accident Investigation Presidential Committee (
At a private hearing held by the Rogers Commission 12 days after the accident, McDonald's, sitting in the auditorium, said, 'NASA hasn't said everything yet!' I mentioned it. Prompted by Senator William P. Rogers to testify, McDonald's said Morton-Thiokol engineers had previously pointed out the hardening of the O-ring, and dissenting opinions were completely ignored. I accused the launch of being forced.
Mr. McDonald said that he covered his face with both hands and cried after finishing appealing everything at the testimony seat. Also, all the other engineers who also testified about NASA's forced launch also shed tears like Mr. McDonald's.
Subsequent investigations revealed that NASA's sloppy safety management and communication was the root cause of the accident. Originally, NASA was obliged to show the 'grounds for high safety' to the engineer team in order to proceed with the launch, but NASA neglected this. In addition, the scientific understanding of NASA's upper management was shallow, and information was not properly communicated between NASA's upper management and engineers, and concerns about the O-ring of the engineer team were widely known within NASA. It has been pointed out that it was not done as one of the causes of the accident.
Furthermore, it turned out that the boss of Morton-Siocall signed the signature that Mr. McDonald's chief engineer refused to sign, and the Challenger was forced to launch. For this reason, the Rogers Commission has ordered NASA to put in place a new safety management system. However, in the 2003 Space Shuttle Columbia disaster , NASA was strongly criticized for 'continuing to downplay safety.'
In addition, it is said that engineers such as Mr. McDonald who made a diving accusation at the hearing were relegated from Morton-Siocall. However, a member of the Rogers Commission questioned the retaliatory personnel and warned that 'Morton-Siocall must be prohibited from signing with NASA in the future.' As a result, McDonald's was promoted to take charge of the redesign of the SRB's connections. McDonald worked for Morton-Siocall until 2001 and wrote a treatise on the Challenger after retirement.
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