Aviation’s Past Indicates Its Future
DESIGN: a hypersonic precooled hybrid air-breathing rocket engine, able to achieve single-stage-to-orbit capability to achieve single-stage-to-orbit capability. In its air-breathing mode, this engine combines a turbo-compressor with a lightweight air precooler positioned just behind the inlet cone. At high speeds this precooler cools the hot, ram-compressed air leading to a very high pressure ratio within the engine. The compressed air is subsequently fed into the rocket combustion chamber where it is ignited along with stored pressure ratio allows the engine to provide high thrust at very high speeds and altitudes. The low temperature of the air permits light alloy construction to be employed and allow a very lightweight engine—essential for reaching orbit. After shutting the inlet cone off at Mach 5.14, 28.5 km altitude, the system continues as a closed-cycle high-performance rocket engine burning liquid oxygen and liquid hydrogen from on-board fuel tanks.
This paragraph defines a seemingly impossible task, creating a single powerplant which functions both in the high density air of the earth’s atmosphere and in the very light air of space. When, not if, it is complete, this engine will be able to travel at 4,000mph. $11 million has been invested in this project, which is expected to produce a demonstrator engine by 2020.
The company, Reaction Engines was founded by Alan Bond, a British engineer has assembled a small team near Oxford. After 20 years of research and design, they have created the concept and may critical working elements of a Synergetic Air-Breathing Rocket Engine (Sabre).
Even the greatest optimist may be incredulous that such an amazing invention can begin testing in four short years.
HISTORY SAYS THAT SUCH NEGATIVITY IS RIGHT; IN FACT IF ALAN BOND IS THE
SIR FRANK WHITTLE OF TODAY, SABRE WILL BE A REALITY
DESIGN: A turbine which converts most of the heat energy into propulsive force in the same way as a rocket, by the kinetic energy of hot gases escaping at high speed from the tailpipe. This engine would essentially be a duct containing a single moving part: a shaft with a compressor at one end driven by a turbine at the other, itself powered by the energy from fuel burned in a combustion chamber between them.
A young test pilot, turned graduate of RAF engineering school and at the University of Cambridge used this description, or a reasonable facsimile thereof, as a proposal to the British Air Ministry, which ridiculed the visionary’s idea as “impractical.” He joined a small company, Power Jets Ltd. where they took the concept and made it into a workable engine. It was mounted in the fuselage of a Gloster E.28/39 airframe. Thankfully, Sir Frank’s vision and dedication resulted in a plane which participated in World War II. Sir Frank Whittle eventually moved to Columbia, MD.
Starting with the Wright Brothers, aviation has progressed because they pursued its visions over the horizon. Bet on 2020 and commercial flight through space in its early test stages.