5 ms·

That sus red smoke is nitrogen tetroxide [0], and the other fuel would be one of the hydrazine derivatives (I believe UDMH [1] here, given that the Twitter thre

That sus red smoke is nitrogen tetroxide [0], and the other fuel would be one of the hydrazine derivatives (I believe UDMH [1] here, given that the Twitter thread says this was a Long March 3B). It's exactly as poisonous as it looks. [0] https://en.wikipedia.org/wiki/Dinitrogen_tetroxide https://en.wikipedia.org/wiki/Dinitrogen_tetroxide [1] https://en.wikipedia.org/wiki/Unsymmetrical_dimethylhydrazine https://en.wikipedia.org/wiki/Unsymmetrical_dimethylhydrazin... edit: Oh yeah, those of you who are concerned about the toxic fumes from gas stoves (popular HN topic), this is exactly* that thing—except the stoves' are measured in micrograms and what you're watching in rocket disaster videos is multiple tonnes. One of these lands on your house, and you will not need to worry about long-term cancer risks ever again. *(To be accurate, NO2 ⇌ N2O4 interconvert in dynamic equilibrium)

KMag 3y ago
> *(To be accurate, NO2 ⇌ N2O4 interconvert in dynamic equilibrium) ... and isn't N02 red while N204 is clear? So, to be pedantic, the red they're seeing is N02?
- perihelions 3y ago
  Exactly!
cmrdporcupine 3y ago
Nicely uphill from the rice paddy this video was taken in, too. I'm sure that rice will be extra delicious as the rains wash the residues into the field. WP about N-Nitrosodimethylamine, which apparently dimethylhydrazine is a precursor to "Contamination of drinking water with NDMA is of particular concern due to the minute concentrations at which it is harmful, the difficulty in detecting it at these concentrations, and to the difficulty in removing it from drinking water. It does not readily biodegrade, adsorb, or volatilize. As such, it cannot be removed by activated carbon and travels easily through soils. "
- justin66 3y ago
  That's a real nightmare. Trace amounts of perchlorates (speaking of rocket chemicals) in water are attributed to some bad health effects, and the compounds you're talking about are so much worse.
ordu 3y ago
> what you're watching in rocket disaster videos is multiple tonnes But this one hardly had multiple tonnes,hadn't it? It was a spent side booster, so the most of the stuff had been burned before the separation, I think.
- onetimeuse92304 3y ago
  When you send a rocket to space, you want a margin for error. Usually this is couple percent for the first stage. Given that the total weight of fuel at launch in this thing is couple hundred tonnes then yes, the margin for error can be multiple tonnes, but we will not know because the exact value will depend on the particulars of this launch.
- nimbius 3y ago
  if its hypergolic fuel you can be almost certain it was less than a few hundred pounds. "tonnes" of hypergolic fuel would be enough to level the hillside and send the iphone through your cranium. most people cannot appreciate just how powerful hypergolic fuels really are. theres just no comparison, even when you see them IRL.
  - perihelions 3y ago
    An example is the 2013 failure of a Proton-M at Baikonur, nearly full of propellant shortly after launch, carrying several hundred tons of hypergolics: https://www.youtube.com/watch?v=rfuXUr-_Rns https://www.youtube.com/watch?v=rfuXUr-_Rns ("Proton M Rocket Explosion 02/07/2013") https://www.youtube.com/watch?v=ycRVAcZC5R4 https://www.youtube.com/watch?v=ycRVAcZC5R4 ("More Videos Of The Russian Proton M Launch Failure And Explosion With Three GLONASS Satellites") (There's lots of different camera angles on YouTube; not sure which one to post).
  - throwawaymaths 3y ago
    Uh for the long march 3b boosters udmh / n2o2 is the primary propellant. That entire booster was full of it, so yes, it's liable to be a tonne or so left over (full propellant mass in the stage is double digit tonnes) https://en.m.wikipedia.org/wiki/Long_March_3B https://en.m.wikipedia.org/wiki/Long_March_3B
itishappy 3y ago
If you're interested in this sort of stuff, I cannot recommend the book Ignition enough. It's got the information density of a textbook, but it's filled with hilarious commentary and fascinating anecdotes. https://library.sciencemadness.org/library/books/ignition.pdf https://library.sciencemadness.org/library/books/ignition.pd...
- cylinder714 3y ago
  Ignition! is back in print, happily.
  - nullhole 3y ago
    Not only that, it's half price! With free shipping! Holiday promo at Rutgers University Press (I'm not affiliated with them, other than being a recent customer :) https://www.rutgersuniversitypress.org/holiday-sale/ https://www.rutgersuniversitypress.org/holiday-sale/ https://www.rutgersuniversitypress.org/ignition/9780813595832/ https://www.rutgersuniversitypress.org/ignition/978081359583...
    - rtsil 3y ago
      Ignition! is the book that reconciled me with chemistry.
      - adastra22 3y ago
        You might also enjoy Alchemy of Air.
        rtsil 3y ago
        Ordered, thank you!
      - cylinder714 3y ago
        I think we all would like to hear your story.
tjpnz 3y ago
SpaceX's Dragon capsule also carries hypergolics and they know not to mess around with the stuff, even trace residues are a concern when egressing astronauts and salvaging the capsule. There are similar stories from the Apollo era. Quite jarring that the Chinese program would knowingly and repeatedly douse civilian populations in them.

KMag 3y ago

> *(To be accurate, NO2 ⇌ N2O4 interconvert in dynamic equilibrium) ... and isn't N02 red while N204 is clear? So, to be pedantic, the red they're seeing is N02?

perihelions 3y ago
Exactly!

cmrdporcupine 3y ago

Nicely uphill from the rice paddy this video was taken in, too. I'm sure that rice will be extra delicious as the rains wash the residues into the field. WP about N-Nitrosodimethylamine, which apparently dimethylhydrazine is a precursor to "Contamination of drinking water with NDMA is of particular concern due to the minute concentrations at which it is harmful, the difficulty in detecting it at these concentrations, and to the difficulty in removing it from drinking water. It does not readily biodegrade, adsorb, or volatilize. As such, it cannot be removed by activated carbon and travels easily through soils. "

justin66 3y ago
That's a real nightmare. Trace amounts of perchlorates (speaking of rocket chemicals) in water are attributed to some bad health effects, and the compounds you're talking about are so much worse.

ordu 3y ago

> what you're watching in rocket disaster videos is multiple tonnes But this one hardly had multiple tonnes,hadn't it? It was a spent side booster, so the most of the stuff had been burned before the separation, I think.

onetimeuse92304 3y ago
When you send a rocket to space, you want a margin for error. Usually this is couple percent for the first stage. Given that the total weight of fuel at launch in this thing is couple hundred tonnes then yes, the margin for error can be multiple tonnes, but we will not know because the exact value will depend on the particulars of this launch.
nimbius 3y ago
if its hypergolic fuel you can be almost certain it was less than a few hundred pounds. "tonnes" of hypergolic fuel would be enough to level the hillside and send the iphone through your cranium. most people cannot appreciate just how powerful hypergolic fuels really are. theres just no comparison, even when you see them IRL.
- perihelions 3y ago
  An example is the 2013 failure of a Proton-M at Baikonur, nearly full of propellant shortly after launch, carrying several hundred tons of hypergolics: https://www.youtube.com/watch?v=rfuXUr-_Rns https://www.youtube.com/watch?v=rfuXUr-_Rns ("Proton M Rocket Explosion 02/07/2013") https://www.youtube.com/watch?v=ycRVAcZC5R4 https://www.youtube.com/watch?v=ycRVAcZC5R4 ("More Videos Of The Russian Proton M Launch Failure And Explosion With Three GLONASS Satellites") (There's lots of different camera angles on YouTube; not sure which one to post).
- throwawaymaths 3y ago
  Uh for the long march 3b boosters udmh / n2o2 is the primary propellant. That entire booster was full of it, so yes, it's liable to be a tonne or so left over (full propellant mass in the stage is double digit tonnes) https://en.m.wikipedia.org/wiki/Long_March_3B https://en.m.wikipedia.org/wiki/Long_March_3B

itishappy 3y ago

If you're interested in this sort of stuff, I cannot recommend the book Ignition enough. It's got the information density of a textbook, but it's filled with hilarious commentary and fascinating anecdotes. https://library.sciencemadness.org/library/books/ignition.pdf https://library.sciencemadness.org/library/books/ignition.pd...

cylinder714 3y ago
Ignition! is back in print, happily.
- nullhole 3y ago
  Not only that, it's half price! With free shipping! Holiday promo at Rutgers University Press (I'm not affiliated with them, other than being a recent customer :) https://www.rutgersuniversitypress.org/holiday-sale/ https://www.rutgersuniversitypress.org/holiday-sale/ https://www.rutgersuniversitypress.org/ignition/9780813595832/ https://www.rutgersuniversitypress.org/ignition/978081359583...
  - rtsil 3y ago
    Ignition! is the book that reconciled me with chemistry.
    - adastra22 3y ago
      You might also enjoy Alchemy of Air.
      - rtsil 3y ago
        Ordered, thank you!
    - cylinder714 3y ago
      I think we all would like to hear your story.

tjpnz 3y ago

SpaceX's Dragon capsule also carries hypergolics and they know not to mess around with the stuff, even trace residues are a concern when egressing astronauts and salvaging the capsule. There are similar stories from the Apollo era. Quite jarring that the Chinese program would knowingly and repeatedly douse civilian populations in them.