Well, Starship is a large reusable spacecraft with a large payload capacity and should be able to carry astronauts. It also uses Raptors, so I will say “yes.”

I have often wondered what a shuttle stack using propellant combinations would look like…for instance, an ET filled with LOX, but with a small hydrazine tank.

I’m not sure that I emphasized the importance of simplicity on the reduction in cost for launching rockets. The Russians and Chinese had undercut American rocket launch prices for a couple of decades before SpaceX caught up with them. Although the Russians (Soviets) experimented often with the more complex forms of rocket engines, they tended to use the least expensive ones and the less expensive methods. The Chinese got a lot of their rocket and spacecraft technology from the Russians, so their philosophies match. Americans tended to prefer performance over low cost, using highly complex methods, hoping for better reliability.

Engineering has had the philosophy of “Keep It Simple, Stupid” (KISS) for many decades. Unfortunately, America’s rocket scientists and engineers chose to maximize performance over simplicity and economy, including using expensive materials and hard-to-handle propellants. Government allowed this choice, willing to fund expensive launch vehicles and spacecraft.

SpaceX made a more instructive philosophy: “The best part is no part.” This needs no mnemonic to remember, as it gives a better visual in one’s mind. Add to it a philosophy of, “If you don’t have to put parts back on, you didn’t take off enough parts.” Once again, one hell of a visual, at least in an engineer’s mind.

The result of these philosophies is lower manufacturing cost, lower operating cost, and higher reliability. Manufacturing may also be faster. Reusability allows for more units to be ready for use without increasing manufacturing rates, so it is easier to reach the launch rates necessary for reusability to break even. SpaceX reached that rate several years ago, and now it is launching at a cadence that would shock the rocket industry just a decade ago. Not just that the cadence is insanely high but that the demand for launches is insanely high. Perhaps another shock would be the insanely high manufacturing rate for Falcon upper stages, almost one every other day, a rate that, until this decade, exceeded the entire world’s launches.

In the 1960s, We the People would not have been so surprised that by now we reached such high demand for orbital launches, because we expected it. We had imagined a high usage of space resources, which is why the movie 2001: A Space Odyssey seemed credible, and why the low usage of the Space Shuttle was such a disappointment. We are twice as far from that time as the movie portrayed, and only now are we beginning to use space in a similar way, a way that we had expected to see long ago.

So, should we be blown away by the high launch cadence and the rapid rate at which boosters and fairings are increasing their usage numbers? No, according to the dreams we had in the 1960s, but yes, according to the reality that government space programs performed over the past half century.

Not sure why anyone would be surprised that kerosene and liquid oxygen work. That was proven successful on the Saturns, if not before. The engine cycle does not have a lot to do with the success of the rocket or the large numbers. It is the original design combined with the improvements made over the first few years of operations. SpaceX kept things simplistic so that failures were less likely and made development and operations inexpensive. Even developing Falcon Heavy only cost half a billion dollars. It is likely that SpaceX has already made back that development cost, but the time to reconfigure the launch pad for future Heavies is likely to start eating into the Falcon 9 launches and the lost opportunity costs of a couple of launches that cannot occur during those transitions.

The simplicity of Kerolox over hydrogen saved a lot of money on operational costs, so the price SpaceX charges can be low. A lack of delta-v efficiency was more than made up for in economic efficiency. This drives more business toward SpaceX and less toward Arianespace, as we have seen. It also encouraged hundreds of companies to try starting operating in space, giving SpaceX a larger customer base and even more business than was available in 2010.

It is all that additional business that is responsible for those numbers. If the planet were still launching less than 100 times a year, how long would it take for Falcons to reach those numbers?

“One would think methane would be cleaner.”

Methane didn’t really become a thing until a few years ago, and it was only a couple of years ago that anyone managed to make it to orbit on methane. I think that some of the recent startups have shown us that it is wiser to make your company’s first rocket out of established technology, because developing new technology can put you into bankruptcy. There are some notable exceptions that have done ok, so far, with some new tech, but they risked a lot to do it. Rocket Lab did electrical turbo pumps, which was rare, and Stoke Space is using some unproven technology.
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Richard M,
You wrote: “SpaceX has banged out 5 Falcon 9 launches in the last seven days. (It’s at 6 if you want to include Starship Flight 11.) It’s really just stunning, and I really should be more blown away by it than I feel like I am.”

Maybe you should.

About a decade ago, ULA bragged loudly about how they had just launched two rockets in six days, each on a different coast. Their launch team would have been especially busy. At least for the way that launches were conducted back then.

I’m not sure how SpaceX does it without burning out their launch teams.

Musk already had a sterling track record as a serial entrepreneur before founding SpaceX and – crucially – he had considerable capital at launch and could get more from his coterie of Silicon Valley friends and co-workers. That meant there was no due diligence visit to NASA by anyone involved. Thus the agency had no opportunity to try scaring off Musk’s investors as it had been uniformly wont to do with other potential investors in prior would-be space launch start-ups.

But there was also some luck involved – most of it bad. As I’ve noted here before, NASA went from killing off potential Shuttle competitors as a matter of policy to suddenly needing such people badly in the wake of the Columbia disaster. NASA’s bad luck transformed SpaceX’s founding moment into a lucky stroke of timing in less than a year.

P.S. Still loving the update for the rankings for the most reflights of a rocket, Bob.

Could that be due to Merlin being open cycle and having lower chamber pressure?

One would think methane would be cleaner.

On biofilms and waste.
https://phys.org/news/2025-10-sticky-cell-problem-bioreactors-industries.html

https://phys.org/news/2025-05-germ-hospital-plastic.html

As both Dennis Prager and William Bennett wrote in several books: “”America – still the last, best hope.””

Only in America could SpaceX happen the way it has developed.

If people with some stones follow in President Trump’s footsteps, we may yet have a chance.

Anent vehicle reuse records, B1067 has flown seven times already this year, averaging about six weeks between successive reuses. So it will almost certainly fly at least once more this year and perhaps even twice. In the first case, it will be sniffing at Atlantis’s heels by year’s end. In the second case, it will have pulled even. If B1067 flies with comparable frequency next year, it will catch Discovery about a year from now and surpass it comfortably by next year’s end.

In addition to being reused, of course, the Shuttle orbiters were also vehicles – Challenger and Columbia notably excepted – that survived re-entries from LEO to Earth’s surface the same number of times they flew. Falcon boosters re-enter, but not from LEO velocity, so the first SpaceX vehicle to best all of the Shuttle orbiters in this more difficult category of achievement will be some yet-to-be-built Starship – most likely a V4 tanker version. Given the virtual certitude that annual Starship flight ops will exceed those of the Falcons as soon as 2027 or 2028, we may have no more than an additional two years or so to wait until said future Starship hits the 40 launch and 40 LEO re-entry marks.