In article . com,
says...

On 2016-10-18 11:11, Fred J. McCall wrote:

What is "COPV" ?


I said it in the original article and you cut it out. Composite
Overwrapped Pressure Vessel.

Sorry, had not made the association between the two. my bad.


TNT is a solid. Does it care about pressure? Yeah, press it and it
makes a really big bang.

yes, but TNT, in solid form is stable until you ignite. It doesn't
expand or create pressure in the lunch box that it us carried into.

No. Most substances are denser in their solid phases than their
liquid phases.

So the fact that some LOX solidified shouldn't magically cause an
increase in pressure in the tank.

No, but this happened when the LOX and helium tanks were being filled.
Increasing the pressure inside the helium tank squeezed the carbon
composite. Since the oxygen trapped in the composite was *solid* it had
nowhere to go and caused the composite to fail. This released a lot of
energy in a very small location that was in direct contact with 100%
oxygen. In other words, an ignition source!

Is it possible that the cold is what did it? If the helium tank was
surrounded by oxygen that it was colder than design, it could have
caused the carbon fibre to become brittle, crack, and let helium out,
causing overpressiure in LOX tank and then things went kablooey ?

Doubtful considering how many times their "life leader" first stage has
been fired (I think they're up to 8 firings after it had been recovered,
which doesn't include the original flight and original test firings).
If any helium tank should have failed due to temperature/pressure
cycling, it should have been one of the helium tanks in that stage.

Jeff
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