Never thought I'd see an article from the Daily Star (basically the UK National Enquirer) on Hacker News [edit: link changed by mods]
Further links here explaining the theory behind the hypersonic engine and hinting the main reason for Boeing producing this concept art (which doesn't have any theoretical specs to back it up) is to draw a bit more attention to its hypersonic military projects which might be a very early starting point for the development of big hypersonic passenger aircraft, maybe, if the economics ever look remotely sane. https://www.popularmechanics.com/flight/a21948533/boeing- https://www.flightglobal.com/news/articles/boeing-unveils-lo...