Though it’s still only a concept, Reaction Engines believes its SABRE — Synergistic Air-Breathing Rocket Engine — is the way of the future for both spaceplanes and conventional, commercial jetliners. With a secret new engine concept and support from the European Space Agency, Reaction Engines is coming ever closer to producing its engine and realizing its beliefs.
The engine would actually revolutionize modern day flight as we know it, being able to switch from in-atmosphere travel to space flight. SABRE has two modes, so to speak. First, the engine would allow a plane to fly to an altitude of 15.5 miles (25km) at around five times the speed of sound. At that height, the plane would only be around 20% of the way to space, so the engine would switch to rocket mode, allowing the plane to gain enough speed and altitude to fly the remaining distance towards space.
If used for conventional, suborbital flight, the engine could allow a plane to travel to any destination on the planet in under four hours. Reaction Engines is so sure of its belief in the conceptual engine that it actually hasn’t even patented special technology used in the design, keeping the ideas as closely guarded as possible.
If Reaction Engines’ concept becomes a reality, not only will the speed of air and space travel change, but it could replace rockets, becoming a more efficient reusable engine. It would be the first engine in history to take a vehicle into space without having to use disposable, multi-stage rockets. We wonder what Elon Musk and SpaceX’s reaction will be.
The engine couldn’t be installed into any plane, and the one that would house it, dubbed the Skylon, is also only a concept, and also kept secret. When SABRE is in plane mode, air must be compressed before being put into the combustion chambers. However, because the air would normally be hot enough to melt the engine, Reaction Engines had to think of a way to quickly cool the air before it went into the engine. If they used a conventional method, it would create frost and cause problems. With the creation of a new heat exchanger, Reaction Engines managed to cool air from 1,832 degrees Fahrenheit (1000C) to -238 (-150C) in 10 milliseconds. Reaction Engines isn’t revealing any details on the new method, calling it the company’s “most closely guarded secret.”
The European Space Agency has been acting as an independent auditor on Reaction Engines’ test program, and on Wednesday gave the project its nod of approval. At the moment, Reaction Engines feels that SABRE is the only engine of the kind in development, and estimates it’d need around $400 million over the next three years to build a smaller version of the engine, which it could have on the market in ten years. If Reaction Engines has its way, the air and space flight industry will be radically different only a handful of years from now.