Hypersonics

Rival powers jockey for the lead in hypersonic aircraft

I've spent my career on things flying fast," says Adam Dissel, who heads up the US operations of Reaction Engines.

This British company is building engines that can operate at dizzying speeds, under conditions that would melt existing jet engines.

The firm wants to reach hypersonic velocity, beyond five times the speed of sound, around 4,000mph (6,400km/h) or Mach 5.

The idea is to build a high-speed passenger transport by the 2030s. "It doesn't have to go at Mach 5. It can be Mach 4.5 which is easier physics," says Mr Dissel.

At those kinds of speeds you could fly from London to Sydney in four hours or Los Angeles to Tokyo in two hours.

However, most research into hypersonic flight is not for civil aviation. It originates from the military, where there's been a burst of activity in recent years.