Space Exploration

Engineers in the United Kingdom have begun critical tests on a new engine technology designed to lift a spaceplane into orbit.  The proposed Skylon vehicle, featuring the innovative Sabre engine would operate like an airliner, taking off and landing at a conventional runway.

Reaction Engine's Skylon vehicle is an unpiloted, reusable spaceplane intended to provide inexpensive and reliable access to space. Currently in proof-of-concept phase, the vehicle will take approximately 10 years to develop and will be capable of transporting 12 tonnes of cargo into space.

The proposed Skylon would operate like an airliner, taking off and landing at a conventional runway.

Its major innovation is the Sabre engine, which can breathe air like a jet at lower speeds but switch to a rocket mode in the high atmosphere.

Reaction Engines Limited (REL) believes the test campaign will prove the readiness of Sabre's key elements.

This being so, the firm would then approach investors to raise the £250m needed to take the project into the final design phase.

"We intend to go to the Farnborough International Air Show in July with a clear message," explained REL managing director Alan Bond.

"The message is that Britain has the next step beyond the jet engine; that we can reduce the world to four hours - the maximum time it would take to go anywhere. And that it also gives us aircraft that can go into space, replacing all the expendable rockets we use today."

Sabre is part jet engine, part rocket engine. It burns hydrogen and oxygen to provide thrust - but in the lower atmosphere this oxygen is taken from the atmosphere.

The SABRE engine is essentially a closed cycle rocket engine with an additional pre-cooled turbo-compressor to provide a high pressure air supply to the combustion chamber. This allows operation from zero forward speed on the runway and up to Mach 5.5 in air-breathing mode during ascent. As the air density falls with altitude the engine eventually switches to a pure rocket propelling SKYLON to orbital velocity (around Mach 25).

• 1. Pre-cooler

  During flight air enters the pre-cooler. In 1/100th of a second a network of fine piping inside the pre-cooler drops the air's temperature by well over 100C. Very cold helium in the piping makes this possible.

• 2. Jet engine

  Oxygen chilled in the pre-cooler by the helium is compressed and used to fuel the aircraft. In the test run, a jet engine is used to draw air into the pre-cooler, so the technology can be demonstrated.

• 3. The silencer

  The helium must be kept chilled. So, it is pumped through a nitrogen boiler. For the test, water is used to dampen the noise from the exhaust gases. Clouds of steam are produced as the water is vapourised.

A video explaining the Sabre engine is also available here.

To have a chance of delivering this message, REL's engineers will need a flawless performance in the experiments now being run on a rig at their headquarters in Culham, Oxfordshire.


So far the testing has been very successful and Skylon and the breakthrough Sabre engine are proving not to be science fiction, but a real revolution in ground-to-space transport. 



SOURCE  BBC

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