The Double Asteroid Redirection Test (DART), NASA's impact spacecraft, is entering the preliminary design phase after NASA's approval on June 23.

Famous disaster films such as Armageddon illustrate potential dangers of asteroid collisions, but DART's goal is to ensure asteroids are never given the chance to 'don't want to miss a thing.'

"Since we don't know that much about their internal structure or composition, we need to perform this experiment on a real asteroid," said Andy Cheng of The Johns Hopkins Applied Physics Laboratory in Laurel, Maryland, the DART investigation co-lead. Cheng also said DART can show us how to protect Earth from asteroids with a kinetic impactor by knocking the hazardous object into a different flight path away from the planet.

DART's Target

NASA, in an official press release, said the target asteroid Didymos (Greek for twin) will approach Earth in 2022 and 2024. Didymos is an asteroid binary system consisting of two bodies designated by Didymos A and Didymos B. DART will collide with Disymos B.

Tom Statler, Program Scientist for DART, said a binary asteroid is the perfect natural laboratory for the test.

"The fact that Didymos B is in orbit around Didymos A makes it easier to see the results of the impact, and ensures that the experiment doesn't change the orbit of the pair around the sun," said Statler.

DART In Action

DART's onboard autonomous targeting system will pinpoint Didymos B and collide with the asteroid at 3.7 miles per second, about nine times faster than a bullet.

The impact will be visible from observatories enabling scientists to gain a greater understanding of kinetic impact as an asteroid mitigation strategy. Slightly lowering the asteroid's speed well before the predicted impact will alter its path. It's a small push that slowly snowballs into a big shift.

Rarity Of Collisions With Earth

NASA established its Planetary Defense Coordination Office (PDCO) in 2016 to find, track and characterize potentially hazardous objects approaching Earth with the assistance of supercomputer simulations

While meteoroids the size of a football come around every 2,000 years, Earth is bombarded with more than 100 tons of dust and sand sized particles daily. Small asteroids almost never reach beyond the upper atmosphere and many others fly by. Nintey three percent of the more dangerous asteroids have already been found, according to NASA.

"DART is a critical step in demonstrating we can protect our planet from a future asteroid impact," said Cheng.