Aren't we getting a bit ahead of ourselves here with talk of hypersonic services from London to Sydney?
This thing is only an engine, and a very experimental one too. The last time they tried to get it going I seem to remember it all ended in tears (probably tears of molten metal)
We are about as far from anticipating 2 hr flights to Oz as Herr Otto was from predicting a Super Constellation on the day he first tried to start his gas engine in 1880-whenever-it-was.
Still, hope it goes OK this time.