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I just checked out the aftermath of the Afterthought party. These aerospace-grade ceramic skulls are meant to be used as fireplace decorations, and so we thought we should test their limits by burning a couple large grains of solid AP rocket propellant. The copper fire pit was mostly destroyed, and the skulls survived pretty much. But some molten residue, perhaps copper, has covered the cranium. Every skull tells a story, and so it goes

6 responses to “Skulls in the Pit”

  1. knotty surprise Avatar
    knotty surprise

    Great experiment! Are the skulls made of alumina ceramics?

    Reply
  2. jurvetson Avatar
    jurvetson

    Let me see if I can find further detail. The instructions brag that they are “made out of a high heat refractory that NASA uses to test rocket engines”

    Meanwhile, prior burns: Rocket Propellant Disposal Party – we melted the metal fire pit!

    Reply
  3. rocketmavericks Avatar
    rocketmavericks

    Mission Accomplished!!!

    Reply
  4. Encountered_on-my_way_ Avatar
    Encountered_on-my_way_

    Great!
    More pictures of the burn would be appreciated.

    The idea seems a little morbid, but for sure is original.

    The ceramic MAY be alumina, because it is cheap, and quite heat refractory, even if not the most: just 2.000oC, while other exotic oxides, nitrides, carbides etc go well above 3.000oC!

    Reply
  5. rocketmavericks Avatar
    rocketmavericks

    The temperature in an aluminized propellant is determined as a function of height and plume depth from diatomic AlO and thermal emission spectra. Higher in the plume, 305 and 508 mm from the burning surface, measured AlO emission spectra show an average temperature with 1σ errors of 2980 ± 80 K. Lower in the plume, 152 mm from the burning surface, an average AlO emission temperature of 2450 ± 100 K is inferred. The thermal emission analysis yields higher temperatures when using constant emissivity. Particle size effects along the plume are investigated using wavelength-dependent emissivity models.

    2980K is 4904 F!! Those heads were toast by design. NASA alumina or anything else didn’t stand a chance. Steve challenged me, and a Maverick always delivers!! Woot!!!

    Besides, its proper environmental engineering to incinerate that propellant. Wouldn’t want all those perchlorates
    leaching into the water table. Steve’s place is the official Mavericks propellant disposal site.

    Wish I could have got a shot of Elon running away. Smart actually, as he had no idea the propellant formulation. Good news is that there was nothing toxic in it other than a little Chlorine gas which dissipates if you hold your breath and don’t breath it.

    Reply
  6. rocketmavericks Avatar
    rocketmavericks

    Steve, do you have a photo of the bag of shock and awe?

    I love the billowing plume!!

    Hmmm…. should start planning for next event. Any requests?

    Reply

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