Airbus may have left Boeing in the dust with 16 times more worth in confirmed contracts—a whopping $44 billion worth—at the Paris Air Show this week, but the real draw for audiences was the unveiling of the new heir to the Aerospatiale-BAC Concorde. Airbus' parent company, European Aeronautic Defense and Space (EADS) presented its concept plane, ZEHST last Sunday.
The name stands for Zero Emission Hyper Sonic Transport, and it will reach speeds of 3,125 mph fueled by a mix of liquid hydrogen and oxygen. The plane intends to carry 100 passengers, launch from a regular runway and though it performs a very steep takeoff (see video below,) it will not have the sonic boom of the Concorde. How nice. Imagine taking off from JFK in a silent rocket and an hour later landing at Heathrow. Spending a weekend in Sydney could be a simple three hour jaunt.
The plane will work on a three-tier propulsion system. The first stage, at takeoff, the plane's air breathing engines (similar to conventional aircraft jets) will run on biofuel (to be made from algae) to climb to the first 16,000 feet. Hydrogen and oxygen will power rocket engines for for the steep ascent to 75,000 feet reaching speeds of Mach 2.5. In the third and final phase two hydrogen-fueled ramjets (ramjets are currently used in missiles) will take the plane to an optimum speed in terms of fuel consumption, most likely beyond Mach 4 (which means four times the speed of sound.) By this point the plane is zooming above the atmosphere.
All of this is supposed to feel pretty much like a regular everyday flight, with passengers feeling nothing more than 1.2 G. To put that in perspective, however, cruising speed for regular planes is about 6 miles up. Transitioning between the three systems will be the technical challenge, but EADS is confident to be flying by 2050. Perhaps it's also necessary to add to the proposed timeline of 40 years, billions of dollars as well.