[jedberg]

I see what you're getting at, but the separate construction and transport was not the issue here. The O ring was a necessary pressure valve, but it failed because the cold made it brittle.

The bigger issue here was the politics between Nasa and it's contractors. The contractors told them that the launch would be dangerous at the temperature, but they were ignored.

[robryk]

> The O ring was a necessary pressure valve (...)

Do I understand correctly that you're saying that the O-ring would be necessary even if the SRBs were constructed as a single long tube, instead of segments that are assembled together?

If so, would you mind expanding on that? I was under the impression that the only reason the whole O-ring and caulking of the joints was necessary was the existence of the joints.

[jedberg]

I'm not a rocket scientist so I might be wrong, but I'm pretty sure the O ring would be required no matter how it was constructed.

[0xffff2]

Why do you think that? As the person you replied to said, the only reason the O-ring is there at all is to seal the joint between the sections. If the join't didn't exist, there would be no reason at all for there to be a rubber ring embedded in the structure.

[jedberg]

Because that spot on the SRB is a flex joint to allow some movement of the nozzle as the engine fires. The joint isn't there because of transportation or other reasons.

[askvictor]

I'm no rocket scientist either, but happened to be reading in depth about SRBs in general and Challenger in particular, and my understanding is: the joint in question was a field joint, to be assembled in the field, as opposed to factory joints which were assembled in the factory. The construction of these joints were different (asbestos insulation vs O-rings). The differing design is due to transportation and logistics.

[robryk]

That spot was the "aft field joint" according to wikipedia. According to the diagram linked[1] that is distinct from the case-to-nozzle joint.

[1] https://science.ksc.nasa.gov/shuttle/technology/sts-newsref/...

[oh_sigh]

And if the politicians didn't vote to build the SRBs in Utah, then maybe there would be no SRB at all, which is a good method to prevent deaths from SRBs.

[0xffff2]

Okay... how is that relevant to my comment at all?

[nerdponx]

I think this was meant to be a comment on the OP.

[gmiller123456]

>The O ring was a necessary pressure valve

Do you have a reference for this? Seems very intriguing to me. To me it seems the last thing you would want, under any circumstances would be to have hot gases coming out anywhere near the hydrogen tank and you'd make every effort to contain any overpressure until it exited beyond the hydrogen tank.

[Pica_soO]

At such projects, everybody is constantly mumbling about what all could go wrong, its just legally relevant background noise- not actually "sticking" out warnings pointing at a particular point of failure.

[kop316]

I'm sorry, You completely mischaracterize what happened that morning. The contractor responsible for the solid rocket booster flat out said "do not fly this love morning". NASA actually went to his supervisor and for his supervisor to sign off on the flight (the particular contractor who refused to sign off said " that was the single smartest decision of his life").

The following is a link to his book, but I actually heard a presentation from him.

https://www.amazon.com/Truth-Lies-Rings-Challenger-Disaster/...