Here’s another cool concept airliner. The Zero Emission Hyper Sonic Transport ( ZEHST) is a supersonic concept passenger airliner that is expected to fly at over Mach 4 on bio-fuel made from seaweed and by oxygen/hydrogen.
The aircraft will feature 3 different types of propulsion systems. The ZEHST will have two high-power, low-bypass turbojet engines without afterburners that will be used for take-off and to fly up to Mach 0.8. This will make the ZEHST no more noisy than any other passenger jet on takeoff and landing. It will then use 2 small and one big liquid hydrogen/liquid oxygen powered booster rocket engines to accelerate up to Mach 2.5. Finally, there will be two air breathing hydrogen fueled under-wing supersonic ramjets that will accelerate the aircraft beyond Mach 4.
Imagine flying from Paris to Tokyo in about two and a half hours compared to around 12 hours on a regular commercial jet. The first flight of the ZEHST is planned for sometime around 2020. Now we just need someone to develop an affordable GA aircraft capable of flying at around Mach 1 on bio-fuel .