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I checked launch cadence, and I am now thinking Ariane is in much bigger trouble than I thought. Ariane 2016: 7 launches (all successful) SpaceX 2016: 9 launc

I checked launch cadence, and I am now thinking Ariane is in much bigger trouble than I thought. Ariane 2016: 7 launches (all successful) SpaceX 2016: 9 launches (8 successes, 1 failure) Ariane 2017: only 1 so far (don't know how many affected by the strike) SpaceX 2017: 4 successes so far. https://en.wikipedia.org/wiki/List_of_Ariane_launches_(2010%E2%80%932019) https://en.wikipedia.org/wiki/List_of_Ariane_launches_(2010%... https://en.wikipedia.org/wiki/List_of_Falcon_9_and_Falcon_Heavy_launches https://en.wikipedia.org/wiki/List_of_Falcon_9_and_Falcon_He...

nojvek 9y ago
For spaceX they just had one failure out of 8. If they have none in 2017 and they can keep up the cadence then it will be a solid blow to rest of the industry. I feel it's a lot easier to make SpaceX's rockets safer than ULA's rockets cheaper and reusable. Once spacex finds their sweet spot in design, they can shooting them up like crazy. I am really looking forward to the moon mission. Last time it happened, I wasn't even born :(
- greenhouse_gas 9y ago
  >I feel it's a lot easier to make SpaceX's rockets safer than ULA's rockets cheaper and reusable. The thing is that safety is cultural, not technical. It means that everyone realizes their limits, and has a conservative streak in them (if it ain't broken, don't fix it, or so least test it like crazy before putting a customers multi-million dollar payload on it). SpaceX, on the other hand, is all about moving fast and iterating fast.
  - ethbro 9y ago
    To be fair, the conservative streak cuts against safety too. I believe a large number of US launch accidents were ultimately attributed to "component or measurement out of spec, but it's worked before so we'll expect it to work again."
    - vanattab 9y ago
      Wouldn't the "conservative" choice in your example be to replace the part or correct the measurement to spec even though it has worked in the past.
      - Tempest1981 9y ago
        I think so. Conservative could mean 1) preferring gradual change over abrupt change, or 2) resistant to any change (stubbornly conservative?)
      - ethbro 9y ago
        Let's label them inertial conservatism and objective conservatism. Where the former is the sense of "we should do things the way we've previously done them" and the latter is "we should do things the most conservative way out of all of our options, even if we've never done it that way before." NASA during Challenger would have been an example of the former [1]. In a way that I think many overly bureaucratic organizations are. The other sense is somewhat oxymoronic given that conservatism is generally resistance to change. So when safety situations arise where the safest option requires acting novelly, who is there to lead the charge? I suppose in that case you'd want a radical safety department. [1] From the NYT article on the findings of the Challenger commission, "As Commissioner Feynman observed, the decision-making was 'a kind of Russian roulette. . . . (The shuttle) flies (with O-ring erosion) and nothing happens. Then it is suggested, therefore, that the risk is no longer so high for the next flights. We can lower our standards a little bit because we got away with it last time. . . . You got away with it, but it shouldn't be done over and over again like that.'" http://www.nytimes.com/1986/06/10/science/shuttle-findings-long-series-failures-key-portions-commission-report-challenger.html?pagewanted=all http://www.nytimes.com/1986/06/10/science/shuttle-findings-l...
  - greglindahl 9y ago
    How can you tell what SpaceX's culture is like? Note that ULA does change things from time to time, but never does a test launch. Meanwhile, SpaceX is on the 3rd or 4th revision of F9, but their accidents have not been related to changes to the rocket.

nojvek 9y ago

For spaceX they just had one failure out of 8. If they have none in 2017 and they can keep up the cadence then it will be a solid blow to rest of the industry. I feel it's a lot easier to make SpaceX's rockets safer than ULA's rockets cheaper and reusable. Once spacex finds their sweet spot in design, they can shooting them up like crazy. I am really looking forward to the moon mission. Last time it happened, I wasn't even born :(

greenhouse_gas 9y ago
>I feel it's a lot easier to make SpaceX's rockets safer than ULA's rockets cheaper and reusable. The thing is that safety is cultural, not technical. It means that everyone realizes their limits, and has a conservative streak in them (if it ain't broken, don't fix it, or so least test it like crazy before putting a customers multi-million dollar payload on it). SpaceX, on the other hand, is all about moving fast and iterating fast.
- ethbro 9y ago
  To be fair, the conservative streak cuts against safety too. I believe a large number of US launch accidents were ultimately attributed to "component or measurement out of spec, but it's worked before so we'll expect it to work again."
  - vanattab 9y ago
    Wouldn't the "conservative" choice in your example be to replace the part or correct the measurement to spec even though it has worked in the past.
    - Tempest1981 9y ago
      I think so. Conservative could mean 1) preferring gradual change over abrupt change, or 2) resistant to any change (stubbornly conservative?)
    - ethbro 9y ago
      Let's label them inertial conservatism and objective conservatism. Where the former is the sense of "we should do things the way we've previously done them" and the latter is "we should do things the most conservative way out of all of our options, even if we've never done it that way before." NASA during Challenger would have been an example of the former [1]. In a way that I think many overly bureaucratic organizations are. The other sense is somewhat oxymoronic given that conservatism is generally resistance to change. So when safety situations arise where the safest option requires acting novelly, who is there to lead the charge? I suppose in that case you'd want a radical safety department. [1] From the NYT article on the findings of the Challenger commission, "As Commissioner Feynman observed, the decision-making was 'a kind of Russian roulette. . . . (The shuttle) flies (with O-ring erosion) and nothing happens. Then it is suggested, therefore, that the risk is no longer so high for the next flights. We can lower our standards a little bit because we got away with it last time. . . . You got away with it, but it shouldn't be done over and over again like that.'" http://www.nytimes.com/1986/06/10/science/shuttle-findings-long-series-failures-key-portions-commission-report-challenger.html?pagewanted=all http://www.nytimes.com/1986/06/10/science/shuttle-findings-l...
- greglindahl 9y ago
  How can you tell what SpaceX's culture is like? Note that ULA does change things from time to time, but never does a test launch. Meanwhile, SpaceX is on the 3rd or 4th revision of F9, but their accidents have not been related to changes to the rocket.