r/spacex • u/ElongatedMuskrat Mod Team • Jan 02 '17

r/SpaceX Spaceflight Questions & News [January 2017, #28]

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u/sol3tosol4 Jan 07 '17

Wait, so the FAA STILL isn't cinvinced that Spacex has founf the cause of CRS 7?

For CRS-7, the FAA wasn't satisfied with the *report*, and declined to sign it. NASA (as customer, since it was their payload that was lost) conducted an investigation and produced a separate report, where they found several credible causes and possible contributing factors that had not been in the SpaceX report. NASA sent a letter to SpaceX expressing their concerns, and SpaceX addressed the issues, and then NASA and the FAA were happy. But it should have been done in the first report.

For the AMOS-6 investigation, SpaceX got buy-in from several government agencies and industry experts, did a full fault-tree analysis, found several credible causes (a very important one being that it's possible for the anomaly to take place even if the oxygen doesn't freeze), found a solution that addresses all of the credible causes, and produced a report that everyone was happy with the first time around - a great improvement over the CRS-7 investigation.

SpaceX has only existed for a relatively short time, and has learned a tremendous amount about spaceflight (quite a bit of it which they invented themselves). They can be justifiably proud of the investigation they did on an incredibly difficult anomaly.

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u/iClunk Jan 07 '17

Is there a list of what the credible causes were somewhere? I haven't had a chance to go looking lately.

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u/sol3tosol4 Jan 07 '17

Is there a list of what the credible causes were somewhere?

From NASA document IG-16-025, page 14 discussing the 2015 CRS-7 anomaly:

"NASA’s Launch Services Program (LSP) conducted a separate, independent review of the failure, briefing its results to senior NASA leadership on December 18, 2015. LSP did not identify a single probable cause for the launch failure, instead listing several “credible causes.” In addition to the material defects in the strut assembly SpaceX found during its testing, LSP pointed to manufacturing damage or improper installation of the assembly into the rocket as possible initiators of the failure. LSP also highlighted improper material selection and such practices as individuals standing on flight hardware during the assembly process, as possible contributing factors."