(CNN) — The aviation industry is in crisis, there’s a global push to cut carbon emissions, and many of us haven’t stepped on a plane or hugged far-flung loved ones in more than a year.
Reviving the supersonic dream that died with Concorde’s retirement nearly two decades ago seems, at first, like an outrageous fantasy.
The British-French airliner Concorde, one of only two supersonic jets to have operated commercially, flew from 1969 to 2003 and was ludicrously expensive and an environmental disaster.
But now a fresh bunch of start-ups are working on supersonic and hypersonic…
