In the past, attempts to design single stage to orbit propulsion systems have been unsuccessful largely due to the weight of an on-board oxidiser such as liquid oxygen, needed by conventional rocket engines. One possible solution to reduce the quantity of on-board oxidizer required is by using oxygen already present in the atmosphere in the combustion process just like an ordinary jet engine.
While this sounds simple, the problem is that in air-breathing mode, the air must be compressed to around 140 atmospheres before injection into the combustion chambers which raises its temperature so high that it would melt any known material. SABRE avoids this by first cooling the air using a Pre-cooler heat exchanger until it is almost a liquid. Then a relatively conventional turbo compressor using jet engine technology can be used to compress the air to the required pressure.
140 atmospheres. To get an idea of that in an engine, consider:
Gasoline engines take in a mixture of air and gasoline and compress it to not more than 12.8 bar (1.28 MPa), then use a spark plug to ignite the mixture when it is compressed by the piston head in each cylinder.
1 atmosphere = 1.01325 bars
This is interesting, first time I've seen it.
I seriously doubt this will make it into commercial passenger jets any time soon, the designs that are needed for the speeds produced by this tech would be pretty tough to apply. Think SR71.
Although, this seems to completely blow every private space plane program way out of the water. Richard Branson is is likely salivating over getting his hands on this engine. They will have immediate sales if they can prove reliability and efficacy.
edit on 30-11-2012 by boncho because: (no reason given)