Nasa makes final steps to launch asteroid deflection test

Dart mission is designed to spot an asteroid on collision course with Earth and deflect its path

Nasa is in final preparations to launch the world's first planetary defence mission. The Double Asteroid Redirection Test (Dart) is scheduled to launch on 23 November and is a joint mission with the Johns Hopkins Applied Physics Laboratory.

Dart is designed to collide with the asteroid Dimorphos and change its orbit as a test for spotting an asteroid on collision course with Earth and deflecting its path.