NASA has announced that SpaceX will fly its Double Asteroid Redirection Test (DART) planetary-defence mission.

 Double Asteroid Redirection Test (DART) is a planned space probe that will demonstrate the kinetic effects of crashing an impactor spacecraft into an asteroid moon for planetary defense purposes

• DART planetary-defence mission will be will launched by the Falcon 9 rocket from Vandenberg Air Force Base in California in June 2021.

• The spacecraft will slam into “Didymoon,” the 540-foot-wide (165 meters) satellite of the near-Earth asteroid Didymos which is located at about 4 million miles from Eart in October 2022.
• Scientists will observe the impact with telescopes and measure the change in the Didymoon’s orbit around the asteroid.

DART won’t be the first spacecraft to wallop an asteroid. Japan’s Hayabusa2 probe smashed a copper cannonball into the space rock Ryugu, to unearth pristine subsurface material for study.