Ogi_UnixNut writes "The Skylon spaceplane is an ambitious project to develop a single-stage-to-orbit craft that can take off and land like a normal airplane. Part of this project requires an engine that can work both as a rocket engine and a normal air-breathing engine (a hybrid approach, essentially). This would reduce the amount of oxidizer required to send stuff into space, and thus greatly reduce the cost. Now, some key experimental parts of the engine have been built, and are to be tested in public at the Farnborough Air Show in the UK in July. The BBC has video of the cooling system being tested."