SABRE aircraft could fly Auckland to London in less than 5 hours 'by 2030s'

Flying between Auckland and London in just a few hours is a step closer as scientists at the UK-based Reaction Engines now say their hypersonic engine will be being used by the 2030s.

The Synergetic Air-Breathing Rocket Engine (SABRE) is being designed to cruise at speeds of Mach 5.4 with a commercial flight and Mach 25 outside the atmosphere on space flights.

Cruising a Mach 5.4 means cruising at 5.4 times the speed of sound, or nearly 6700km/h.

"When we have brought the SABRE rocket engine to fruition, that may enable us to get to Australia [from London] in perhaps as little as four hours," Graham Turnock, head of the UK Space Agency, told CNN.

"This is technology that could definitely deliver that. We're talking the 2030s for operational service, and the work is already very advanced."

Travelling at hypersonic speeds can cause dangerously high engine heat levels, but SABRE has developed a pre-cooler heat exchanger. That extracts the heat through fine tubes that are fed with chilled helium and then uses the heat to power the engine.

"The main thing with SABRE is it's like a hybrid of a rocket engine and an aero engine, so it allows a rocket to breathe air," said Shaun Driscollof Reaction Engines.

"Rockets really haven't progressed in 70 years, whereas aero engines have become very efficient, so if you can combine an aero engine and a rocket you can have a very lightweight efficient propulsion system and basically create a space plane."

Reaction Engines' SABRE project is now being supported by the UK Space Agency and the Australian Space Agency in an agreement dubbed a "world-first Space Bridge".

That agreement was announced recently at the UK Space Conference 2019.