3 ms·
> To do this, helium is rapidly pushed through a check valve - designed with low-molecular-mass helium in mind - to physically pressurize the propellant systems
by accrual 7y ago
> To do this, helium is rapidly pushed through a check valve - designed with low-molecular-mass helium in mind - to physically pressurize the propellant systems. Unintentionally, the NTO that leaked 'upstream' through that valve effectively was taken along for the ride with the high-pressure burst of helium. In essence, picture that you crash your car, only to discover that your nice, fluffy airbag has accidentally been replaced with a bag of sand, and you might be able to visualize the unintended forces Dragon’s check valve (the metaphorical airbag) was subjected to when a "slug" of dense oxidizer was rammed into it at high speed.
This paragraph really drove the point home for me. I was able to easily visualize the event.
- wizardforhire 7y agoClassic Water Hammer! https://en.wikipedia.org/wiki/Water_hammer https://en.wikipedia.org/wiki/Water_hammer
- lutorm 7y agoWell "classic" water hammer doesn't involve the water igniting with the pipe material... ;-)
- wizardforhire 7y agoTotally! You get a water hammer and thermite reaction all in one go! Eeeek!
- gpm 7y agoIs metal burning with a non-metal-oxide oxidant a thermite reaction?
- TheSpiceIsLife 7y agoAren't all these thermite oxidisers metals or metalloids? Bismuth(III) oxide, boron(III) oxide, silicon(IV) oxide, chromium(III) oxide, manganese(IV) oxide, iron(III) oxide, iron(II,III) oxide, copper(II) oxide, and lead(II,IV) oxide. https://en.wikipedia.org/wiki/Thermite https://en.wikipedia.org/wiki/Thermite