Brussels to Sydney in less than three hours.

A passenger jet could one day fly halfway around the world in just a few hours. That’s the goal of the High-speed Experimental Fly project (HEXAFLY): going beyond the supersonic realm pioneered by the now-defunct Concorde to reach hypersonic speeds more than five times as fast as sound.

Led by the European Space Agency, the project has now brought on international collaborators to prepare for an early stage test flight planned for 2020.

Professor Andrew Neely is an aerospace expert at UNSW Canberra who is testing models in wind tunnels to help refine the design of the test vehicle.

“The real hypersonic airliner would need to be about the size of an A380,” Andrew says. “The test flight will use a 3-metre scale model. We’re testing small models of that model, about 15 or 20 centimetres long.”

At hypersonic speed, air behaves differently, particularly in how it transfers heat to the plane, and a mistake can mean blowtorching off a tailfin. The details are not yet as well understood as researchers would like, so computer models are still of limited use.

“We use a special wind tunnel at the University of Southern Queensland to get the high speeds,” Andrew explains. Using a small model means they can easily 3D print new ones to test ideas, and the results can still be applied at larger scales.

The larger-scale test flight is planned for 2020. The model vehicle will be hurled into the upper reaches of the atmosphere on a Brazilian rocket, then glide back to the ground with a top speed of around seven times the speed of sound.

Banner image: Hypersonic vehicles could be the future of passenger flight. Credit: HEXAFLY