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Comment by userbinator | Hacker News Reader

The solid oxygen that formed could have ignited with the carbon, causing the explosion that destroyed the rocket.

This makes me wonder why the liquid oxygen wouldn't have the same effect? Liquid oxygen is itself an extremely reactive oxidiser (search YouTube videos.)

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There's no ignition source normally — the liquid oxygen isn't under as much pressure, it's just sitting in the tank under nominal conditions. The idea is that the solid oxygen formed underneath the top layers of the carbon overwrap. Then as the aluminum liner of the the tank (which is under the composite wrapper) expanded as the tank was filled, the solid oxygen was subjected to enormous pressure, creating the ignition source — right next to a fuel source (the carbon composite), all in a big tank full of oxidizer.

If true, this implies that they have a porous material in a place they shouldn't.

Unfortunately it's REALLY hard to create a completely non-porous composite.

On the topic of the dangers of LOX, here's a really fun campy Air Force training video from the 60s:

https://www.youtube.com/watch?v=rUKcHe0-m_I

Completely OT but this has to be the weirdest training video I have ever seen.

I am like 90% sure that they filmed that as a 70's porno movie and just cut out all the "interesting" parts out to make this instruction video....

Case and Point: https://youtu.be/rUKcHe0-m_I?t=175 (same video just a time stamp at 2m 55s) potentially NSFW....

But honestly what drugs were the guys on when making this, and how the hell was this ever accepted by the USAF?!

I guess the higher ups figured it was one way to keep young males focused on the film.

It's just the culture of the time period (late 1960s.) I remember watching some automotive repair videos from roughly the same era, and they would be just as outrageous today.

On the other hand, it definitely makes things memorable.

Could it be sharp oxygen crystals penetrating the carbon fiber resin layer - just like what happens when freezing living cells?

>> Could it be sharp oxygen crystals penetrating the carbon fiber resin layer

Why would one keep just a layer of hardened resin between all that oxygen and carbon? Seems like an accident waiting to happen.

I'm guessing the reason you don't do a lot of "Plan B" mitigation in rocketry: weight and added complexity.

The carbon fiber and resin are the shell (AKA a straight jacket) over usually a thin titanium vessel.

Carbon fiber alone won't be enough to keep liquid helium at least from precipitating through it, the darn thing can leak through solid glass when it's cold enough.

Not sure about liquid oxygen, but still there is no carbon fiber on the inside of the tank, if nothing else than to ensure that no particulate matter ever gets into the fuel system.

Liquid oxygen would just get pushed out of the space by the increasing pressure. The solid oxygen exploded because it couldn't 'get out of the way'.

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