A cube-shaped "impactor" spacecraft, about the size of a vending machine, was scheduled to crash with the asteroid Dimorphos, about the size of a football stadium.
The spaceship will slam with the asteroid at high speeds to see whether they can change its course using kinetic force, with the goal of deflecting it away from Earth.
This is the first time that anybody has ever tried to manipulate the orbit of a celestial body, much alone an asteroid.
When it reaches its destination, the SpaceX rocket that carried the November 2021 launch of DART will pass over control to the autonomous.
The impact scheduled for Monday night will be tracked in real time at the Johns Hopkins University Applied Physics Laboratory (APL) mission .
The asteroid "moonlet" that DART will be aiming for is approximately 560 feet (170 metres) in diameter, and it circles an asteroid named Didymos .