Here is a glimpse of the future. By 2050, seaweed-powered space-liners will fly from London to Tokyo in two-and-a-half hours, at a cruising altitude of 20 miles and generating no significant pollution.
This is not the speculative vision of a latter-day Jules Verne but the confident prediction of the Airbus parent company, EADS, which will unveil its plans for a hypersonic, stratospheric airliner, the Zehst, at the Le Bourget airshow near Paris today.
The Zehst - or "Zero emission hypersonic transportation" - will fly twice as fast and twice as high as Concorde, if joint European and Japanese development plans come to fruition.
The likely cost of a 90-minute "space flight" from Paris to New York would be NZD$10,500 per passenger. The Zehst, which resembles a lightweight version of the US Space Shuttle, would carry up to 100 passengers at speeds of up to 4800kph.
The aircraft would have three different forms of propulsion in order to eliminate noise problems and meet future ecological constraints. The plane would take off using quiet turbo-reactors powered by a biofuel made from seaweed or algae.