There is a growing interest in the airline industry to bring back supersonic passenger air travel. We have seen several companies backed by industry heavyweights like Airbus, Boeing, and even NASA showcase their concepts and prototypes in the recent past. However, there is a UK-based company that is building a completely new type of engine that will be capable of propelling an aircraft to speeds nearing Mach 5.5 (5.5 times the speed of sound). Reaction Engines Ltd (REL), the company behind the novel engine, says an aircraft equipped with the propulsion unit can travel from London to Sydney in about four hours – a journey that usually takes close to 20 hours. The engine is named SABRE (Synergetic Air-Breathing Rocket Engine) and the European Space Agency (ESA) and the UK Space Agency (UKSA) recently took a look at the preliminary design for it, giving it a nod for key demonstration and testing.
The Sabre engine will not only be used in aircraft propulsion for rapid travel inside the atmosphere, but it will also be used in powering re-usable space vehicles to reach straight to the orbit without the need for multiple propellant stages. The Sabre is designed to operate like an air-breathing jet engine from standstill to Mach 5.5 inside the atmosphere and then transition to rocket mode at high altitude, with the capability of reaching 25 times the speed of sound to get into space. For this extremely complicated design to work, it uses a compact pre-cooler heat-exchanger that can take an incoming airstream in the region of 1,000C and cool it to -150C in less than 1/100th of a second. “The positive conclusion of our Preliminary Design Review marks a major milestone in Sabre development,” ESA’s head of propulsion engineering Mark Ford told the BBC. “It confirms the test version of this revolutionary new class of engine is ready for implementation.”