Son of Concorde? Great-great-grandchild, more like, given that the original supersonic airliner was based on 1950s technology, and the Zehst is not scheduled to rip through the skies until a century later. But even if you are confident that you will be alive, wealthy and inclined to foreign travel in 2050, don't bet on stepping on board.
The Anglo-French Concorde was a hyper-expensive misadventure. BA could not make the sums add up, so the plane flew into glorious oblivion eight years ago.
Speed is seductive. But a far cheaper and more pragmatic solution is to enhance the journey, with on-board Wi-Fi or innovative high-density-business-class configurations that can put flat-bed comfort within reach of travellers like you or me. That is the real cutting edge of air travel.