Boom Supersonic, which officially launched last fall, says it is developing the next generation of supersonic plane, which it intends to start flying in the early 2020s (while it plans the first flight of its demonstrator plane, the XB-1 next year). Last November, the company said Richard Branson’s Virgin Group had taken options on its first 10 planes. But today, Boom said it has struck deals with five (unnamed) airlines on the sale of 76 planes–and says those carriers have committed to “tens of millions in non-refundable payments.” Boom’s special sauce is a design that is expected to make the plane economical enough for passengers to buy tickets at about the price of today’s business-class tickets, and that promise led an industry analyst to predict that airlines will eventually buy on the order of 1,300 of the $200 million planes. And on the strength of that, the company said in March it had raised $33 million in new funding. Whether anyone will ever step onto one of these planes is unknown, but at this stage, at least, all the signals point to the resumption of one of aviation’s most romantic and exciting eras, not to mention the ability to get from New York to London in less than 3 1/2 hours.