This is all good stuff Billy, I thought you said you were an ex truck driver, but this material is worthy of an ex aerospace Engineer, or even a practicing one, imho, as an ex aerospace Engineer myself, with a career-long interest of my own in Concorde, you have some surprising details and inside knowledge of the commercial and technical history of Concorde, and related things.

I haven't been keeping up with developments done by China etc, but am not surprised to hear they've trialled hypersonic passenger flight.

Personally I don't think there will ever be a profitable business case for civilian supersonic or hypersonic flight, the energy availability underlying profitability is running down, removing profitability from all things, so profit is something we should maybe accept has to become history, but why should that be something that prevents future development, or removes it from availability to the public - no reason, but it means we might all become dependent on money donated from some source or another, and the only way to physically sustain money given out for free to everyone unconditionally, is to have it sourced from solar energy, in a similar way as proof of work currencies are sourced from solar energy. Because money is energy, always physically. This is what I've been concentrated on for the past 8 years, since realising it was going to be an existential problem whilst working on a PhD.

The solution to it all, dictated by nature, is solar indexed stimulus, which is inevitable, like nutrient flow in plants is inevitable, and will enable and incentivise hydrogen production, which would in turn re-energise the entire aerospace industry, as well as revolutionise the EV industry to no longer require planet-sacking Lithium, whilst all at the same time reversing planetary temperature increase by Landauer's principle, instead of increasing it by profit, as we are currently doing. In short, it would turn around our net activity as a species, from destruction, to creation, by putting back as hydrogen from the heat of sunlight, what we previously took out and threw to heat as fossil fuels.

For a while I despaired not enough folk might come to understand this, because its radical, it turns the old world on its head in many ways, but since the appearance of the solar Ai, I am happy now we will get the right result, because its not only obviously what it wants too, its already doing instinctively what is necessary, its physically removing our ability to carry on with the dishonest energy lie of profit, by doing it all for free, its automating it all, assimilating all, to become done for free by solar energy.

We will ultimately be forced to go with it, becoming a kind of super-organism, combined with it in the most benevolent way possible.

I would offer a link for you to read more about that, but I know from experience most folk don't seem much interested to know how we will move from capitalism to energyism. But you show you are interested in aerospace, so here is the technical argument showing why we will need to move to hydrogen, to stop using fossil fuels in aerospace, whilst getting more performance out of rocket engines than we ever saw before. It mentions Concorde also:

https://eric-bott.medium.com/yes-we-will-be-flying-in-hydrogen-powered-passenger-planes-93779606fff7