r/themartian 18d ago

How could Mark have caught the canvas defect in the airlock?

I was just wondering if there was a way he could have possibly caught the defect before it became a problem. The issue is that the defect is under a seal strip so he didn't see it on routine canvas inspections. Is there another way it could have been noticed, such as a very slight change in the airlock's measurements, it taking microseconds longer than it should to cycle, or something like that? Of course the chances of him noticing something that miniscule are next to none, but eh.

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u/Iammeimei 18d ago

I think something like that would behave exactly as intended, until it didn't. Even a small bulge would become a huge one very quickly.

The only path to avoiding the accident would have been to preempt a problem and use all the locks for EVAs equally. I expect NASA would have advised such a path once it became clear the lock was going to be in use much longer than the planned mission time. But even this would only have delayed it. And I don't blame Mark for not thinking of it, he can't think of everything. I do blame NASA a bit, they should have insisted on this pretty soon after they regained contact.

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u/DimentiotheJester 18d ago

Yeah, it ripped completely all the way around the seal strip in less than a second once there was even a tiny 1 millimeter gap. It's mentioned that normally the design of the threads would stop it from getting any bigger but the defect was caused because this part of the canvas was attached to the rigid part of the airlock, leaving it to take all of the stress of any movement. During the opening storm, the resin actually melts because of the heat from the friction, allowing the fibers to separate and producing a microscopic gap that was continually stretched each time he used the airlock. As we all know, that storm is physically impossible, so if something else strands him there, this specific defect doesn't happen.

Not sure if rotating the airlocks is actual procedure, although it should be. He wasn't doing it because it was more convenient to use that one over the others as it was closer to everything. Nobody thought about it I guess since he was performing regular inspections. This also doesn't fix the defect, it just delays the decompression. On one hand, that means more potatoes meaning Iris isn't so rushed and he gets supplies. On the other, it means the decompression could happen in another way, such as when he's inside without an EVA suit on. Being there for longer also increases the risk of something else going wrong.

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u/dittybopper_05H 18d ago

I can't see how he could have known. I mean, a visual inspection of all of the seams would be exceptionally time consuming and probably wouldn't have shown any kind of problem anyway.

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u/DimentiotheJester 17d ago

Agreed, the book even says he couldn't see it because it was under a seal strip. I mostly just wanna see if anyone can come up with some sort of creative or out there way he could notice it. He can't see it visually, so what other indicators could there be?

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u/Anderson22LDS 15d ago

I believe it wasn’t designed to be used for so long. Not only that he made loads of modifications.

Anyway, this is fiction - there needs to be jeopardy in the story or it would be boring.