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Rockets Blow Up… How Often?

Posted by on | November 9, 2017 | Comments Off

On reading this article about a SpaceX rocket engine blowing up during testing, I thought to myself that rockets sure seem to blow up a lot, even with 60 years of experience.   If I had had to guess, I probably would have guessed 10-20% of the launches fail.

But it turns out that this is an exaggeration, probably due to the summer of the shark effect I have discussed before.  One problem with the data is that I would define failure rate from a customer point of view — did my payload survive and was it inserted into the right orbit where it can do what I want it to do.  A lot of the data on failure rates uses other bases.  From this page, in 2016, the failure rate by my definition would be 3 out of 86 launches, or 3.5%  (that site reports a failure rate of 2 out ob 85, but do not count the pre-launch explosion of a SpaceX rocket that destroyed the payload).    This page has answers to the failure rate question in the 6-8% range for unmanned rockets over the history, with a bit of a trend downwards recently.  Apparently the failure rate on manned launches is much lower.

I guess my reaction is that the failure rate is lower than I would have guessed, but I think my perception that it had not improved a lot over 50 years may be correct.  I don’t have the data but my sense is that air travel experienced a much faster rate of improvement in catastrophic failure rates, though the engineering calculus between manned (most air travel) and unmanned (most rockets) travel may be different.  Certainly if it cost $100 million per rocket to reduce the failure rate by a percent or two, it might not make financial sense if there are no people on it.

 Rockets Blow Up... How Often?  Rockets Blow Up... How Often?  Rockets Blow Up... How Often?

 Rockets Blow Up... How Often?

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