Planes this fast will need new technologies of propulsion, new materials and completely new designs, developed by research and industrial partners from Europe and Japan.
JAXA proposed its long-term vision, “JAXA2025,” to realize its own mission. The vision to demonstrate the technologies for hypersonic aircraft that can cruise at Mach 5 speed and cross the Pacific Ocean within two hours.
JAXA is developing the pre-cooled turbojet engine (PCTJ), which can operate from take-off to Mach 5 continuously. The engine has already demonstrated at ground experiments and a flight experiment up to Mach 1.8. Presently, Mach 5 flight demonstration using hypersonic technology experimental aircraft (HYTEX) is planned.
The greatest technical challenge for realization of hypersonic aircraft engines is to prevent overheating due to incoming air. Flying at Mach 5 will cause the temperature of the incoming air to climb as high as 960°C. Normal turbo jet engines cannot be used in such a high-temperature environment. To solve this challenge, the IAT hopes to use an air precooling system to dramatically expand the operable range of the turbo jet engine. In this system, an air precooler installed upstream of the compressor will cool the hot air captured at the air intake.
Read More: http://arc.aiaa.org/doi/abs/10.2514/6.2014-2790
Conceptual diagram of spaceplane mounted with the precooled turbo jet engine