Nasa launches spacecraft in first ever mission to deflect asteroid

Spacecraft heads off on 6.8m-mile journey to crash into moonlet Dimorphos in test to see if asteroids can be diverted from collision with Earth

A spacecraft that must ultimately crash in order to succeed lifted off late on Tuesday from California on a Nasa mission to demonstrate the world's first planetary defence system.

Carried aboard a SpaceX-owned Falcon 9 rocket, the Dart (Double Asteroid Redirection Test) spacecraft soared into the sky at 10.21pm Pacific time from the Vandenberg US Space Force Base, about 150 miles (240km) north-west of Los Angeles.