Hypersonic passenger planes -- and one-hour flights from New York to London -- have been touted for around 60 years. The question is not whether some military or private aircraft will achieve this goal, but when -- or if -- Joe and Jane Carryon will commute on one.
In his 1986 State of the Union address, U.S. President Ronald Reagan called for the development of an ''Orient Express,'' a plane that could jet from New York to Tokyo in two to three hours. The planned Rockwell X-30, a single-stage-to-orbit (SSTO) passenger space liner, was kiboshed before reaching the prototype stage [source: Sanger].
Supersonic flight might return, but probably not soon. In 2012, one contender under development is the Zero Emission Hypersonic Transportation (Zehst) system, the seaweed-biofuel-powered brainchild of a collaboration between EADS and Japan, who plan to roll out the craft around 2040 or 2050 [sources: Jones; Wall]. Zehst will travel at double Concorde's speed and altitude, at a ticket price of around €6,000 ($8,500) [source: Lichfield].
If successful, Zehst will carry 50-100 people between Paris and Tokyo in 2.5 hours (compared to the current 11) using three propulsion systems. Two turbofans will propel the plane on a steep climb to around Mach 0.8, after which two rocket boosters will take over, accelerating the vehicle to Mach 2.5 -- fast enough for ramjets to kick in and boost the plane to around Mach 4. Approaching its destination, the plane would glide in, with its turbofans kicking on again, and land under power [source: Wall].
Airbus' main competitor, Boeing, abandoned its supersonic Sonic Cruiser to develop the subsonic 787 Dreamliner, but you can never count the company out completely -- particularly given its military contracts, which keep it firmly in the high-speed aircraft game. Despite its dodgy test record, the technology behind Boeing's X-51A WaveRider -- which flies on its own shock wave and has broken Mach 5 multiple times -- could form the foundation for eventual space or commercial applications [sources: Bartkewicz; Boeing].
Meanwhile, European aeronautical company HyperMach has announced SonicStar, a sonic-boom-less plane designed to fly twice as fast as Concorde. According to HyperMach, SonicStar will cruise at Mach 3.6 at an altitude of 60,000 feet (18,300 meters) and carry 10-20 passengers between New York and Dubai in two hours, 20 minutes. The company believes it can get the plane flying by June 2021 [source: Jones].
Taking a suborbital approach, California-based aerospace firm XCOR is working on Lynx, a two-seat commercial aircraft designed for high-altitude, supersonic flight. If successful, Lynx will cruise at more than 2,500 mph (4,000 kph) to an altitude of 62 miles (100 kilometers), then descend, minimizing troublesome atmospheric drag, friction and turbulence [source: Waldron].
All things considered, exchanging the hypersonic dream for hyperbolic flight might make practical sense.