Famous UK based company, Reaction Engines Limited, acquired additional funds for development of their futuristic engine, which could be base for future single-stage-to-orbit reusable vehicle.
It is another success of REL after announcing about planned financial engagement of BAE Systems into development process of SABRE on November 2nd, 2015. BAE planned to invest around £20 million in project along with British government which assigned grant of £60 million. Project was also interesting for ESA, which is strongly looking for opportunities to reduce costs of delivering cargo to orbit and would warmly welcome any additional competition of Arianespace. Now we know for sure: ESA announced on July 12, 2016, about investing Reaction Engines Limited with €10 million. It is confirmation of success of previous cooperation between REL and ESA-Agency supported Reaction Engines during design process since 2008, especially in terms of future adopting engine to manufacturing. Joint efforts of REL, UK government, ESA and BEA Systems have one objective: first demonstration test in flight planned for 2020.
Reaction Engines Limited was founded in 1989 by one of designers of HOTOL experimental space planes, Alan Bond; he invented SABRE engine using his own project of RB545 engine, which was created for Rolls-Royce. Unique feature of SABRE is operating in two different modes: jet and rocket. For jet mode, SABRE is utilizing atmosphere oxygen cooled to almost liquid state. In rocket mode, conventional oxidizers are utilized instead of oxygen from atmosphere. Engine is able to work as jet engine and fluently switch to rocket mode after reaching space. Vehicle equipped with such propulsion would be able to operate as ordinary cargo plane; start vertically from runway and reach high altitude, where ordinary jet plane could not operate due the limited amount of oxygen. Next after switching engines to rocket mode, it could easily continue flight to LEO, deploy payload, perform reentry like Space Shuttle and land on runway. This could be possible due the few advantages of SABRE; it saves oxidizer and fuel operating in atmosphere where rocket engines are not as efficient as jet engines. Rockets are wasting most of their oxidizer before they reach space, but vehicle equipped with SABRE is able to take more fuel using oxygen from atmosphere and limiting usage of oxidizer from tanks only to space flight. Of course it makes possible reducing cost of space flight due the resignation from tons of oxidizer; another important thing is, that this engine is reusable and according to REL it is even possible to use same unit hundreds of times. Last fact is using ordinary runway instead expensive launch sites and fact, that plane could be assembled as ordinary jet plane. Ready to flight vehicle could just start and land on designated runway to take payload and deliver it to orbit. At the moment, Reactional Engines Limited is developing own robotic spaceplane called Skylon (on picture above). It planned as long for 83 m with wingspan of 26 m spaceplane able to be use up to 200 times. In equatorial start it would be able to deliver to 600 km orbit 2700 kg of payload or up to 30 passengers to LEO orbit with utilization of special pressurized module.
You can read more about Skylon here.