Is superfast really better? An airliner that can reach six times the speed of sound is being developed, but some worry about its effect on the environment.
2030 forecast: travel goes hypersonic
Whizz kid: Venus Aerospace's Stargazer is powered by a rotating-detonation engine that spins at 20,000 rotations per second. Glossary
Hypersonic - Travelling at speeds of more than five times the speed of sound (Mach 5).
Ramjet - A type of jet engine that draws in air using the forward speed of the vehicle and compresses it for combustion.
Mach - A unit of measurement charting the speed of an object in relation to the speed of sound. Travelling at Mach 1 means travelling at the speed of sound.
Sonic boom - A loud explosive sound caused by shockwaves created when an object travels faster than the speed of sound.
Nasa - The National Aeronautics and Space Administration, responsible for the US space programme.
Prototype - Original or test version of something.
AI - A computer programme that has been designed to think.
Barcelona - A city in Spain's Catalonia region, known for its architecture and art.
