from the they-might-need-a-duvet-with-all-theose-sheets dept.
Nikkei Asian Review reports that SpaceX is establishing a business relationship with Japanese material manufacturer Toray Industries. They're supposedly working on a $1.99 billion to $2.98 billion USD deal in which Toray will supply SpaceX with sheets of carbon fiber.
The two sides are aiming to finalize the agreement this fall after hammering out prices, time frames and other terms.
The likely plan is to supply carbon fiber sheets from a Toray production center in Alabama, with SpaceX to further process the material into end products. Adding dedicated production lines at a South Carolina plant will be considered if SpaceX's demand for carbon fiber grows as expected.
In Ars Technica's regurgitation of this story, one delicious chunk of information is brought to the surface (albeit coated in the putrid vile of a misused "irony"):
In a bit of irony, Toray is likely to produce carbon fibers for SpaceX at its Decatur, Alabama-based factory, which is located in the same city where SpaceX competitor United Launch Alliance manufactures its rockets.
One angle the Nekkei Asian Review article touches on is that per-rocket cost should matter less now that SpaceX is successfully landing rockets.
SpaceX aims to hold down expenses by re-using rockets and spacecraft. Originally, the company made rockets mostly out of aluminum to keep costs low, using carbon fiber only for a few parts, such as connecting joints.
Another angle mentioned is SpaceX's ambitions for Mars.
SpaceX is switching to carbon fibers from aluminum as it develops heavy rockets for carrying people and large quantities of material. A lighter body would allow more cargo to be loaded, which would cut transport costs.
The Falcon Heavy rocket, currently under development, would carry more than three times the payload that the Falcon 9, the current model in service, is capable of handling. The rocket is slated for a test launch as early as the end of the year. SpaceX will start launching satellites next year and carry out a joint unmanned mission to Mars with NASA in May 2018.
Do Soylentils think that this move towards carbon fiber has more to do with reusable rocket advances, or the requirements of Mars missions? Are those issues even separable? What other angles should we be discussing?
Popular Mechanics has interviewed SpaceX CEO Elon Musk about his decision to move to a stainless steel design for Starship Super Heavy (formerly BFR). The interview reveals new details about the design, including micro-perforations on the outside of the windward side of the rocket that can bleed water or fuel for cooling:
Ryan D'Agostino: How does stainless steel compare [to carbon fiber]?
Elon Musk: The thing that's counterintuitive about the stainless steel is, it's obviously cheap, it's obviously fast—but it's not obviously the lightest. But it is actually the lightest. If you look at the properties of a high-quality stainless steel, the thing that isn't obvious is that at cryogenic temperatures, the strength is boosted by 50 percent.
Most steels, as you get to cryogenic temperatures, they become very brittle. You've seen the trick with liquid nitrogen on typical carbon steel: You spray liquid nitrogen, you can hit it with a hammer, it shatters like glass. That's true of most steels, but not of stainless steel that has a high chrome-nickel content. That actually increases in strength, and ductility is still very high. So you have, like, 12 to 18 percent ductility at, say, minus 330 degrees Fahrenheit. Very ductile, very tough. No fracture issues.
[...] [Here's] the other benefit of steel: It has a high melting point. Much higher than aluminum, and although carbon fiber doesn't melt, the resin gets destroyed at a certain temperature. So typically aluminum or carbon fiber, for a steady-state operating temperature, you're really limited to about 300 degrees Fahrenheit. It's not that high. You can take little brief excursions above that, maybe 350. Four hundred, you're really pushing it. It weakens. And there are some carbon fibers that can take 400 degrees Fahrenheit, but then you have strength knockdowns. But steel, you can do 1500, 1600 degrees Fahrenheit.