A Falcon 9 launches from Vandenberg Space Force Base in California, carrying the DART spacecraft on its terminal mission to the Didymos binary asteroid system. (NASA)
A SpaceX Falcon 9 rocket lifted NASA's Double Asteroid Redirection Test (DART) mission payload out of Vandenberg Space Force Base in California on 24 November 2021, the first tangible mission under the US banner of ‘planetary defense'.
The spacecraft is on a circa10-month journey to cover the 6.8 million miles to the binary asteroid system Didymos, where it will deliberately impact on the 160-m diameter moonlet Dimorphos, orbiting the main Didymos asteroid.
It is anticipated that the 610 kg DART's 6.6 km/s impact will deflect Dimorphos' orbit around Didymos by several minutes, which will be ascertained by terrestrial sensors. This will in turn be verified by a European Space Agency mission named Hera, which is set to launch in 2024 and conduct high-resolution surveys of the Didymos pair from 2026.
This marks the first attempt by humanity to deliberately interfere with celestial bodies and to defend the planet from hazardous impacts.
Neither of the Didymos bodies is in danger of colliding with Earth. The trial is intended to build data on the viability of any future attempt should a dangerous asteroid be detected.