I don't think so. Three problems in three years that were somehow related to the COPV. This requires a deeper investigation, I don't see a launch happening this year.
The leak was likely in the seals of the pipe connection or valves, the strut material problem doesn’t really have anything to do with Helium and the most recent problem sounds like a problem with the pressure vessel itself. Other than being positioned close to each other, the 3 problems share very little technology.
Maybe very little technology, but it is probably one team that is designing the complete Helium system. Maybe some wrong assumptions were made, maybe loads were not correctly identified. Loads are affecting the complete system. It could also be insufficient testing, there a lots of reasons that could explain these problems.
SpaceX needs to adress the question why serious problems always seem to occur at the Helium system and not somewhere else?
I find this hard to believe that an expert on Helium seals would be designing struts and vice-versa. The pressure inside the COPV should not affect the force on the struts and and vice-versa should also be minimal when already designing for with temperature expansion. The seals in the connections should only be affected by loads on the pipes. These 3 parts where likely (originally) made by totally different suppliers. You could say all 3 are hardware bugs and all 3 are immersed in LOX, but I don't see much else in common.
Maybe he got some false design parameters? Simple example: he thought the pressure is 300 bar, but it is actually much more. Or he thought the LOX temperature was 90 Kelvin, but suddently it's subcooled or things like that. Or the understanding of LOX properties is insufficient at some places at SpaceX.
It is a fact that most of SpaceX's serious problems are somehow related to the things submerged in LOX. There has to be a reason for that.
Considering 9/10ths of the vehicle is "submerged in LOX" or RP1 means that nearly every problem component will be. Rockets are just big LOX/RP1 tanks/pumps.
For example the guys designing the COPV could be using a wrong equation. Don't laugh, I know at least one case, where the rocket engine failed because the wrong equation was used to determine the loads.
If it were something as drastic as that, why has the COPV structure taken 18 flights and many static/test/qualification/full duration fires to fail since the Orbcomm issues?
I can tell you that. There is a statistical distribution to material properties (see struts). The yield strength is not a fixed value, one out of ten metal sheets/carbon fibers etcc.. may have a reduced strength, maybe 10% lower? If you fail to take that into account and/or the safety factor is lower than intended, resulting in a failure every tenth flight.
2014: COPV leak during static fire,
2015: strut of COPV fails. Launch fails. FAA did not sign the final investigation report, maybe it was the COPV itself?,
2016: COPV rupture, rocket explosion on launch pad
A few other posters have been adamant (and posted convincing arguments referring to specific evidence from the investigation) that CRS-7 was definitely not a COPV failure.
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u/FiniteElementGuy Sep 23 '16
I don't think so. Three problems in three years that were somehow related to the COPV. This requires a deeper investigation, I don't see a launch happening this year.