4 ms·
To really be sure they got to the bottom of the issue and are not seeing an intermittent issue they should duplicate the failure, but it may not be possible to
by asmithmd1 10y ago
To really be sure they got to the bottom of the issue and are not seeing an intermittent issue they should duplicate the failure, but it may not be possible to do this safely. I detect a little bit of hand waving around the source of ignition:
"breaking fibers or friction can ignite the oxygen in the overwrap"
I would like to see at least this ignition source duplicated.
- ghshephard 10y agoI also found it a little surprising with so much involved that they didn't take the effort to reproduce the failure case, perhaps doing so on a smaller scale than a full vehicle launch if possible.
- snrplfth 10y agoThe problem is that accurately reproducing this failure case is very difficult. You need to replicate the thermal properties of the loading process and the tanks, at the same speed with the same amounts of propellant and helium, effectively meaning that you have to do it with a full-size tank, and with a large amount of pad equipment. This is all extremely dangerous and almost certainly will result, if successful, in the loss of the testing stand.
- lutorm 10y agoIt doesn't specify whether the mechanism proposed to have caused this particular anomaly has been experimentally verified to be able to cause ignition but, even if it had, it would still not prove it was the mechanism that was at work in this particular instance.
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- asmithmd1 10y agoYes, proposing a theory and reproducing a result experimentally doesn't prove anything - but it is the basis of all science.
- lutorm 10y agoMy point is that the wording "several credible causes for the COPV failure" does not imply they haven't experimentally verified that those causes can cause a COPV failure, which you seemed to imply.
- greglindahl 10y agoNote that the company that used to produce COPVs for SpaceX had a large explosion during testing at their factory. Some testing now takes place on barges at sea, and the huge carbon-fiber tank for ITS was also tested at sea.
- tbabb 10y agoWho says they didn't repro the failure?
- robryan 10y agoThey have duplicated the failure at their test site, possibly a number of times. At least one was mentioned but there have been multiple explosions.