Even as the Indian Space Research Organisation is attempting to create its own air-breathing engine, BAE Systems on Monday, 2 November, announced that it would invest €20.6 billion in Reaction Engines Limited to produce an air-breathing rocket engine.

Known as SABRE (Synergetic Air-Breathing Rocket Engine), it will have the capacity to pick up five times more the speed of sound from the runway. Then it can adopt rocket speed, close to orbital velocity and equivalent to 25 times the speed of sound in the atmosphere.

This  hybrid rocket or jet engine will let passengers fly anywhere around the world in four hours.

Reaction Engines has already undertaken several large, independent technical evaluations that have verified the engine's feasibility and potential vehicle applications, said an official release.

BAE, who, after investing, will own 20% stake in Reaction, is expected to provide its aerospace technology development and project management proficiency in making the hybrid engine.

The UK government is also expected to offer €60-million funding in SABRE's development as well as examine its applications for space-access vehicles.

Mark Thomas, Managing Director of Reaction Engines, said the announcement has proved the company has come a long way from concentrating on researching and testing technologies for the SABRE engine to researching and testing the engine itself.

"BAE Systems brings industry-leading capabilities in programme delivery and wider engineering-systems integration that will accelerate the development of SABRE as a new engine class and its vehicle applications. This partnership builds on the outstanding technical breakthroughs that Reaction Engines has made and the positive assessments received on the potential of the technology from experts at the European Space Agency and the United States' Air Force Research Laboratory (AFRL)," he explained.

UK-based Reaction Engines has one key challenge to face though: Controlling the hot air that will enter the engine at high speeds. The gases have to be cooled off before those get compressed and burnt with the hydrogen aboard.

For this challenge, Reaction has created a module consisting of a series of very fine piping, which can draw the heat and cool the hot air rushing in to nearly 140 degrees C in just a hundredth of a second. It is very lightweight — approximately 100 times lighter than present technology — permitting it to be used for aerospace purposes for the first time.