5 ms·

What's the purpose of the methane purge?

• baking 6y ago
  It was not intentional. There must be some mechanism to disconnect the external propellant lines before lift-off and they obviously disconnected unintentionally after the static fire. The best guess based on the way the flame spread was that both lines disconnected and there was a mixture of methane and oxygen just waiting for the right fuel-oxygen ratio before it was ignited on any number of post-burn hot spots. (I haven't seen any new info recently so this explanation may have been already superseded by more recent analysis.)
  • rrmm 6y ago
    From just the video it didn't look like a very fast burn. I wouldn't be surprised if it was just methane, or at least a non-stoichiometric mixture. (Could also just be poorly mixed).
    • sq_ 6y ago
      Scott Manley posted on Twitter [0] that it looks like it was a proper detonation (supersonic flame front, etc.) based on some math given the known size of the test rig and rocket. [0] https://twitter.com/DJSnM/status/1266586181392674817?s=20 https://twitter.com/DJSnM/status/1266586181392674817?s=20
      • rrmm 6y ago
        Cool! I missed the shock front. I guess the cloud was a lot bigger than I was giving it credit for. thanks for the update. EDIT: oh man I just saw another view of it in the twitter thread. It was proper!
  • baking 6y ago
    Elon Musk confirmed on Twitter that they were testing the "quick disconnect."