British engineers have begun a crucial series of tests of an experimental engine technology that its designers believe could revolutionise space travel.

The Skylon project is a concept for a spaceplane which could fly from runway to orbit in a single stage.

The key is a unique design for an engine that operates as a jet and rocket motor combined.

The critical component is a specially-designed cooling system to handle the high temperatures of rapidly-flowing air.

David Shukman was given exclusive access to the tests at Culham Science Park in Oxfordshire.