The US space agency, NASA, has successfully flown an experimental hypersonic plane over California at speeds reaching 5,000 miles an hour, seven times the speed of sound.
The un-piloted X-43A aircraft used what is called a scramjet engine that could one day usher in a new generation of space shuttle propulsion systems.
Scramjets burn hydrogen but take their oxygen from the air, which is forced into the engine at very high speed.
The technology could one day pave the way for faster long-distance air travel and cheaper access to space.
