NASA Launches Asteroid Redirection Test(DART)

The Double Asteroid Redirection Test (DART) is aimed at learning how to neutralize a potential threat from a wayward asteroid.

The DART mission launched atop SpaceX's Falcon 9 rocket (at 0620 UTC, Nov. 24, 2021) from Space Launch Complex 4 here at Vandenberg Space Force Base in California.

The Falcon 9 booster returned to Earth -- nearly 9 minutes after liftoff -- to an upright landing on SpaceX's 'Of Course I Still Love You' drone ship which was stationed in the Pacific Ocean. The landing marked the 95th time that the company has recovered an orbital class rocket booster.

The DART spacecraft will use a "kinetic impact technique," to alter the orbit of an asteroid. It will impact a "moonlet" called Dimorphos that orbits around a much larger asteroid Didymos and the mission teams aims to shorten its orbit around Dimorphos by several minutes.

DART will intercept the Didymos system between Sept. 26 and Oct. 1, 2022, intentionally slamming into Dimorphos at roughly 4 miles per second. Scientists estimate the kinetic impact will shorten Dimorphos’ orbit around Didymos by several minutes. Researchers will precisely measure that change using telescopes on Earth. Their results will validate and improve scientific computer models critical to predicting the effectiveness of the kinetic impact as a reliable method for asteroid deflection.

DART’s one-way trip is to the Didymos asteroid system, which comprises a pair of asteroids. DART’s target is the moonlet, Dimorphos, which is approximately 530 feet (160 meters) in diameter. The moonlet orbits Didymos, which is approximately 2,560 feet (780 meters) in diameter. 

If in the future, a large asteroid were identified to pose an extinction-level threat to Earth, NASA could theoretically send out a spacecraft like DART to smash into it and push it in a different direction.

"It's an intentional crash of a spacecraft into a rock," Thomas Zurbuchen, NASA's associate administrator for the science mission directorate said during a news conference on Monday. "What we're trying to learn is how to deflect a threat."

Neither the asteroid nor its moonlet poses any danger of making their way toward Earth, regardless of the outcome of the test.