Hypersonic speed is defined as a velocity of mach 5 or greater. Things that travel at hypersonic speeds in real life include:
Certain kinds of bullets
Certain experiment military aircraft
Intercontinental ballistic missiles
Various spacecraft
Meteors
The earth itself, in its orbit around the sun
In the OBD, anything in the mach double digits range is hypersonic+and anything with a speed of mach 100 or over is defined as massively hypersonic.
Hypersonic speed is one step above supersonic, with the next speed category being relativistic. However, there is a huge gap between the beginning of hypersonic speed and the beginning of relativistic speed, so this term is not very descriptive without more specific information.
A computer model of a Boeing X-43 flying at mach 7
See also:
- FTL
- Speed