Our generalization defect

2018-11-26

in Books and literature, Geek stuff, History, Space and flight, STS-27/107

One big surprise from Michael Leinbach and Jonathan Ward’s Bringing Columbia Home: The Untold Story of a Lost Space Shuttle and Her Crew is the claim that people at NASA hadn’t anticipated the catastrophic loss of a Shuttle during reentry. That despite of the delicacy of the thermal protective tiles and the fatal consequences expected from their failure, the lack of engines and thus any way to salvage a single failed landing attempt, and the long period of commitment to a particular landing site from deorbit burn to touchdown. The lesson drawn from Challenger, in spite of all the training of all the people at NASA in statistics and rigour, is that ‘these things fail during liftoff’ — a bit of a mad generalization for a vehicle built to take the crew through a series of environments, each of which would almost immediately kill them without technological protection, from the extremely high pressure from drag at max-Q during liftoff, through the fatal vacuum of space, through fiery reentry through plasma above mach 18 to an unpowered glider landing. Assuming that the first thing that went fatally wrong would be the standard is like getting on the back of a charging bull covered in poison-tipped spines in the middle of a minefield and thinking: “This is the one that kills you by stomping on your head”.

One small quibble: the subtitle of this book is misleading. I expected it to be much more about Columbia’s crew and final mission, whereas the bulk of it is about the debris recovery efforts across the country after the shuttle disintegrated.

{ 2 comments… read them below or add one }

. September 27, 2019 at 10:15 pm

“All the tests and analyses lead to the conclusion that defects in the application of the foam insulation could cause foam debris to be generated during the early supersonic phase of shuttle flight. We informed the foam technicians at our plant in Michoud Louisiana that they were the cause of the loss of Columbia and then worked them overtime in training with new and exhaustive techniques on how to apply foam with no defects.”

https://waynehale.wordpress.com/2012/04/18/how-we-nearly-lost-discovery/

. September 28, 2019 at 6:13 pm

They showed cracks in the foam. Foam where no installation defects existed. It turns out that the thermal cycles associated with filling the tank could crack the foam, especially in areas where there were two or more layers of foam. This never showed up in the partial panel tests; it only showed up when we “tested” a complete tank.

Finally, this explained the Columbia foam loss. And the Discovery foam loss. And it had nothing to do with the improper installation of the foam.

I flew to New Orleans within a few days, and called an all hands meeting where I publicly apologized to the foam technicians. They had not caused the loss of Columbia through poor workmanship. Those guys were reeling from the hurricane’s devastation to their homes and community, and has lived with nearly 3 years of blame. Thin comfort for me to apologize: so late, so little.

https://waynehale.wordpress.com/2012/04/18/how-we-nearly-lost-discovery/

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