The rumored funding amount is £60Million ($90Million). This would not be full Phase 3 funding. It would help get private cofunding.
The hybrid engine – its name stands for Synergistic Air-Breathing Rocket Engine – is currently being developed by Reaction Engines, based at Abingdon, near Oxford.
Unlike conventional aircraft engines, SABRE switches in flight to become a rocket engine that can boost Skylon to a speed faster than Mach 5, or more than five times the speed of sound.
It works like this. After take-off, SABRE first mixes hydrogen with air it sucks in. Then it switches to rocket mode, using oxygen carried in its own tanks to accelerate into space.
The breakthrough in the engine’s development came when SABRE engineers showed they can cool the incoming airstream from a temperature of over 1,000 C to -150 C in less than a hundredth of a second without the engine frosting up.
Skylon’s 82-metre long fuselage will be built from carbon-fiber reinforced plastic with a black ceramic skin to protect against the heat of re-entry. It will be powered by two SABRE engines.
Fine Tubes manufactured over 2000km of tubing for Skylon, with each tube at a wall thickness of just half the diameter of a human hair. Reaction Engines’ objective is so challenging that a lot of goals had to be met; the tubes had to be lightweight, highly heat and pressure resistant, and have a strength that could cope with thermal expansions. The resulting heat exchangers are 100 times lighter than existing technologies and enable the cooling of airstreams from over 1000°C to -150°C in less than 1/100th of a second.
Reaction Engines will continue towards the next phase of testing in building the prototype of a fully functioning engine.
After this testing success, the technologies involved in Skylon’s SABRE engine are now being applied to other projects, for example the second phase of the LAPCAT (Long-term Advanced Propulsion Concepts and Technologies) project. This will have mach 5 commercial jets that can go across the Pacific in 4 hours.