Double Asteroid Redirection Test (DART) mission

Context

The National Aeronautics and Space Administration (NASA) is about to launch its Double Asteroid Redirection Test (DART) mission.

About the Launch

• It is the first Kinetic Impactor Method of planetary defence, where a DART spacecraft will be colliding with the asteroid Dimorphos.
• The Kinetic Impactor Method involves sending one or more large, high-speed spacecraft into the path of an approaching near-earth object. 
• This could deflect the asteroid into a different trajectory, steering it away from the Earth's orbital path.
• Data obtained from DART’s crash will be compared to the data from various computer simulations run by scientists to ascertain whether this kinetic impactor method will remain a viable option in case of an actual threatening asteroid.
• Scientists don’t yet know the exact mass of Dimorphos but it is estimated to be around five billion kilograms. 
• The DART spacecraft weighs around 600 kilograms.

About the DART Mission 

• It is a planetary defence-driven test of technologies for preventing an impact on Earth by a hazardous asteroid. 
• The spacecraft will be launched on a SpaceX Falcon 9 rocket from Vandenberg Space Force Base in California.

Objectives

• DART is the first technology demonstration of the kinetic impactor technique that could be used to mitigate the threat of an asteroid hitting Earth. 
• The kinetic impactor mitigation technique is the impulsive deflection of the asteroid through the sudden addition of momentum. 
• In simpler terms, DART is being sent to collide with an asteroid to change its orbital period.

Targeted asteroid by the DART mission

• It will target Dimorphos, the much smaller “moonlet” of a binary (two-body) asteroid system.
• Dimorphos orbits a larger asteroid named Didymos (Greek for “twin”) which has a diameter of 780 metres. 

Why Dimorphos?

• Didymos is a perfect system for the test mission because it is an eclipsing binary which means it has a moonlet that regularly orbits the asteroid and it can be seen when it passes in front of the main asteroid. 
• Earth-based telescopes can study this variation in brightness to understand how long it takes Dimorphos to orbit Didymos.