3 ms·

I’m not sure if they developed them themselves, but the alloys SpaceX uses in the pre burners in the raptor engines are really advanced and likely have not been

I’m not sure if they developed them themselves, but the alloys SpaceX uses in the pre burners in the raptor engines are really advanced and likely have not been known (in the US) before. They have to be able to withstand pure (nearly) oxygen gas at very high temperatures and pressures. I wouldn’t be surprised if these super specialize alloys were developed by spacex. The Soviets figured it out during the end of the space race and US engineers basically assumed they were lying bc they thought the metallurgy was impossible.

shapefrog 4y ago
SX 300 & soon SX 500. Kind of a modern version of Inconel superalloys Inconel is known in the US as it was invented there in the 1930s - well before Musk was born. They might be called superalloys, but there is nothing particularly sophisticated about them from a scientific perspective. SX300 / SX500 are minor revisions which take some R&D but technologically it is 1930's stuff.
- dotancohen 4y ago
  This is plain wrong. In the US it was assumed that Oxygen-rich preburners would erode any manufacturable material - metal, ceramic, or exotic. When the RD-170 (If I remember correctly) was found to have an oxygen-rich preburner, very knowledgeable people called it a lie, misrepresentation, or proclaimed that is was severely wearing (possibly ablating) and thus had to be very heavy. The Raptors are reusable (even air-ignitable, with centisecond timing precision to achieve a specific thrust) engines with an oxygen-rich preburner, and to boot they have the highest chamber pressure of any rocket engine ever. Thus, they also have a very high (possibly highest, we don't know) pump pressure (the preburner _is_ the pump), and they're doing that with oxygen-rich combustion. There is some crazy material making up that preburner chamber, and the pipes down to the pintles. Materials that until recently were though to be beyond manufacturing capability. And this is in a reusable engine that costs less than an RD-68. Frankly, it looks like magic.
  - shapefrog 4y ago
    Elon Musk disagres with what you think Elon Musk does. https://twitter.com/elonmusk/status/1008385171744174080 https://twitter.com/elonmusk/status/1008385171744174080
    - dotancohen 4y ago
      I made no reference to Elon Musk, I do not see why you are invoking him here. I should have been more specific. My response regarding "plain wrong" is in response to this: > They might be called superalloys, but there is nothing particularly sophisticated about them
- deleted 4y ago
  [deleted]

shapefrog 4y ago

SX 300 & soon SX 500. Kind of a modern version of Inconel superalloys Inconel is known in the US as it was invented there in the 1930s - well before Musk was born. They might be called superalloys, but there is nothing particularly sophisticated about them from a scientific perspective. SX300 / SX500 are minor revisions which take some R&D but technologically it is 1930's stuff.

dotancohen 4y ago
This is plain wrong. In the US it was assumed that Oxygen-rich preburners would erode any manufacturable material - metal, ceramic, or exotic. When the RD-170 (If I remember correctly) was found to have an oxygen-rich preburner, very knowledgeable people called it a lie, misrepresentation, or proclaimed that is was severely wearing (possibly ablating) and thus had to be very heavy. The Raptors are reusable (even air-ignitable, with centisecond timing precision to achieve a specific thrust) engines with an oxygen-rich preburner, and to boot they have the highest chamber pressure of any rocket engine ever. Thus, they also have a very high (possibly highest, we don't know) pump pressure (the preburner _is_ the pump), and they're doing that with oxygen-rich combustion. There is some crazy material making up that preburner chamber, and the pipes down to the pintles. Materials that until recently were though to be beyond manufacturing capability. And this is in a reusable engine that costs less than an RD-68. Frankly, it looks like magic.
- shapefrog 4y ago
  Elon Musk disagres with what you think Elon Musk does. https://twitter.com/elonmusk/status/1008385171744174080 https://twitter.com/elonmusk/status/1008385171744174080
  - dotancohen 4y ago
    I made no reference to Elon Musk, I do not see why you are invoking him here. I should have been more specific. My response regarding "plain wrong" is in response to this: > They might be called superalloys, but there is nothing particularly sophisticated about them
deleted 4y ago
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