The Double Asteroid Redirection Test (DART) is no longer a concept. It’s now moving into a design phase, which could make it the first ever demonstration of asteroid deflection.
“DART would be NASA’s first mission to demonstrate what’s known as the kinetic impactor technique — striking the asteroid to shift its orbit — to defend against a potential future asteroid impact,” said Lindley Johnson, planetary defense officer at NASA Headquarters in Washington. “This approval step advances the project toward an historic test with a non-threatening small asteroid.”
An asteroid known as Didymos will be DART’s first target. It makes a distant approach to Earth in October 2022, and then again in 2024. Didymos is greek for “twin”, aptly named as the asteroid is a binary system of two bodies: Didymos A, about one-half mile (780 meters) in size, and a smaller asteroid orbiting it called Didymos B, about 530 feet (160 meters). DART’s target will be the smaller of the two asteroids.
DART will achieve kinetic impact with Didymos at a speed of approximately 6 km/s, guided by it’s onboard cameras. The hope is that, “The collision will change the speed of the moonlet in its orbit around the main body by a fraction of one percent, enough to be measured using telescopes on Earth.”
DART is powered by theNASA Evolutionary Xenon Thruster – Commercial (NEXT-C), it’s a highly advanced system that will decrease the cost of the launch vehicle for leaving Earth. It was previously used on the Dawn spacecraft propulsion system and was developed at NASA’s Glenn Research Center in Cleveland, Ohio.
“DART is a critical step in demonstrating we can protect our planet from a future asteroid impact,” said Andy Cheng of The Johns Hopkins Applied Physics Laboratory in Laurel, Maryland, the DART investigation co-lead. “Since we don’t know that much about their internal structure or composition, we need to perform this experiment on a real asteroid. With DART, we can show how to protect Earth from an asteroid strike with a kinetic impactor by knocking the hazardous object into a different flight path that would not threaten the planet.”