Ars Technica: On Tuesday, UK-based Reaction Engines signed a £10 million contract with the European Space Agency for the development of their Synergistic Air-Breathing Rocket Engine (SABRE). That agreement fulfilled a funding requirement for an additional £50 million from the UK Space Agency. Reaction Engines says that the new funding comes on top of an earlier £20.6 million from BAE Systems and allows the company to develop a ground-based demonstration SABRE engine by 2020. SABRE is a hybrid rocket–jet engine that functions as a jet at low altitudes and as a rocket at high altitudes. The company says the design is possible because of its pre-cooling heat exchanger, which can cool incoming air from 1000 °C to –150 °C in 1 ms (and prevent freezing by injecting methanol into the cooling system). In theory, the engine would be able to power a spaceplane from a horizontal take off all the way to low Earth orbit. This single-stage-to-orbit reusable launch system would be a potentially significant alternative to traditional rockets.
