A non-stop flight between London and Sydney has long been seen as the holy grail of air travel. It is a fair description too – not in the sense of a sacred cup, but in that, for as long as humanity has enjoyed the luxury of the jet engine, a direct service between these two great cities on opposite sides of the planet has been both hugely desired and out of reach.

The magic moment is coming closer, though. Last May, Qantas declared that it was on the verge of breaking through what might be described as the final frontier of commercial air travel. It unveiled the plan, somewhat grandiosely, under the name “Project Sunrise”.

The Telegraph London