A British firm has recently revealed it is working on a commercial jet engine that would be able to fly 300 passengers around the world at five times the speed of sound, or Mach 5.

Reaction Engines is working on SABRE, the Synergetic Air-Breathing Rocket Engine, which can fly passengers from Europe to Australia, for example, in about four hours, according to Tech Times.

The way it will work is by cooling the engines by more than 1,000 degrees Celsius in .01 seconds, without causing any ice blockages, said Alan Bond, chief engineer at Reaction Engines, Business Insider reports. 

Bond said the ability to cool faster allows the engine to run at higher speeds than existing engines.

The most unique aspect of this process is that the engine "breathes" in atmospheric air, according to iflscience.com.

It accomplishes this by the use of several thin pipes, which are arranged in a swirl pattern. The pipes help extract heat from the air, by the condensed helium filled in the pipes, and cool it down to -150 degree Celsius.

This means that 250 tons of oxygen can be captured from the atmosphere and then used in the combustion process. This helps reduce the amount of oxygen that needs to be carried in propellant tanks.

The ultimate benefit of this process is that it overcomes previous limits of aircraft design by decreasing the weight of the craft.

But the uses for such an engine can expand beyond commercial flights.

The firm creating SABRE will be installing it in the reusable spaceplane SKYLON.

The plane can take off from a runway, transform into a rocket to fly into orbit and then return for a runway landing. Test flights are planned for 2019.

The company is also considering using the craft to transport passengers into space, possibly for a ticket price of around $435,000. But it would be without a view since the craft will not have windows.