Attempts Are Underway To Build Hypersonic Passenger Plane---European Space Agency

When Concorde was decommissioned in 2003, supersonic air travel became a thing of the past. But work has begun on a passenger aircraft that could go further and faster, flying from Europe to Australia in four hours. Will it ever become a reality? The European Space Agency’s goal is to create a hypersonic passenger plane, one that flies more than five times faster than the speed of sound and six times faster than a standard airliner.
It’s not the first time hypersonic flight has been attempted. In 1960, tests took place on the X-15 - half plane, half missile - which carried one pilot and flew for 90 seconds before its rocket fuel burnt out.
Its creators thought it would herald a new era of high-speed civil aviation but more than 50 years later, a hypersonic passenger plane has yet to be tested or even built. Now a team led by the European Space Agency, known as Lapcat, are working on an aircraft called the A2, which could take up where the X-15 left off. The technology involved in exceeding the speed of sound - Mach 1 - is extremely complex. “Mach number is the key,” says aerodynamics expert at Imperial College London, Paul Bruce. When you go below Mach 1, so flying slower than the speed of sound, and then go above Mach 1, the physics changes, he says. “When you go to Mach 5 or 6 the laws start changing once again.” At hypersonic speeds, gasses and metals behave very differently. Airliner engines that work at subsonic speeds - about Mach 0.85 or 913km per hour - won’t work.