I think the talk of hypersonic civilian transport is basically a fig leaf. I don’t think in a world with video conferencing and lie-flat business class, that t

I think the talk of hypersonic civilian transport is basically a fig leaf. I don’t think in a world with video conferencing and lie-flat business class, that there is a commercially viable hypersonic transport. Even the Concorde struggled and hypersonic transport is likely to have more even more fuel and space trade offs. And the Carbon output per passenger mile is likely to be astronomical. Now the military has a completely different set of trade offs and hypersonic vehicles and weapons have enough tactical and strategic importance that cost is not a huge limiting factor. At the same time, there are people that will feel bad about supporting/working for a pure military company, so having at least the possibility of civilian transport soothes a lot of consciences.