Falcon 9 rockets could make Musk money, Walter Isaacson explains (in his biography of Elon), but it would take a BFR to make human life multiplanetary:
The Starship system would have a first-stage booster and a second-stage spacecraft that together stacked to be 390 feet high, 50 percent taller than the Falcon 9 and thirty feet taller than the Saturn V rocket that was used in NASA’s Apollo program in the 1970s. Outfitted with thirty-three booster engines, it would be capable of launching more than a hundred tons of payload into orbit, four times more than the Falcon 9. And someday it would be able to carry a hundred passengers to Mars.
The Starship was originally going to be made of carbon fiber, but it was hard to work with:
Musk knew that the early Atlas rockets, which in the early 1960s boosted the first four Americans into orbit, had been made of stainless steel, and he had decided to use that material for the body of the Cybertruck. At the end of his walk around the facility, he got very quiet and stared at the ships coming into the port. “Guys, we’ve got to change course,” he said. “We are never going to build rockets fast enough with this process. What about going with stainless steel?”
[…]
“Run the numbers.” When they did so, they determined that steel could, in fact, turn out to be lighter in the conditions that Starship would face. At very cold temperatures, the strength of stainless steel increases by 50 percent, which meant it would be stronger when holding the supercooled liquid oxygen fuel.
In addition, the high melting point of stainless steel would eliminate the need for a heat shield on Starship’s space-facing side, reducing the overall weight of the rocket. A final advantage was that it was simple to weld together pieces of stainless steel. The aluminum-lithium of the Falcon 9 required a process called stir welding that needed to be done in a pristine environment. But stainless steel could be welded in big tents or even outdoors, making it easier to do in Texas or Florida, near the launch sites. “With stainless steel, you can smoke a cigar next to it as you weld it,” Musk says.
Elon Musk, Man of Steel.
Another story of a (almost) lost technology. How did Musk’s engineers not know about the earlier use of stainless steel?
Someone asked a NASA engineer why NASA wasn’t using the F1 engines that powered the Apollo missions. He answered they didn’t know how to build them. The existing drawings and specifications were not detailed enough.
I used to tell my students that nothing important was written down. All the important stuff was transmitted orally, person to person.
That is why the loss of industrial jobs is so important. The US has literally forgotten how to build things.
Bob Sykes’ comment is interesting. I agree about the importance of oral transmission of knowledge, but there is a counter example. I understand that South Korea built some of its industrial infra-structure with virtually no tradition of industrial know-how. They used textbooks, even in things like road-building. It can’t have been easy.
Steel became unsexy when Lawyer Central Command decided to shiv real industrial production (dirty and manly) and replace it with computer-based pixel-pushing makework (clean and feminine).
If you’re looking for the real locus of power, by the way, avert your eyes from the clown show on television and start eyeballing the American Bar Association, National Conference of Commissioners on Uniform State Laws (a.k.a. Uniform Law Commission), American Law Institute, National Judicial College, Harvard Law School, Yale Law School, University of Chicago Law School, and so on.
Did you know that substantially every judge in the U.S.A. is trained at one facility in Reno, Nevada? It’s true.
South Korea was built on the experience of 40 years of industrialization by the Japanese. They had plenty of roads, railroads, and ports, built by Korean workers and Japanese (and later Korean) engineers.
Seoul National University of Science and Technology traces its origin to a public vocational school founded in 1910. And Keijo Imperial University (renamed to Seoul National after the war, the Harvard of Korea) had an engineering department in 1938.