In an age of rapid, multifaceted technological development, aerospace organizations continue to investigate practical solutions to issues that the cosmos, specifically asteroids, may impose on our planet. Among these fascinating developments, a collection of scientists from NASA and John Hopkins University’s Applied Physics Laboratory made a headlining breakthrough with their Double Asteroid Redirection Test (DART), surfacing global news in September 2022. Tasked with creating a device to mitigate the paths of near-Earth objects (NEOs) in November 2021, the team devised a plan to collide a human-made spacecraft into a nearby asteroid and observe if the impact yielded significant changes.
Didymos, meaning “twin” in Greek and hence the derivation of “double” within the DART mission, was the ideal target for the inaugural redirection experiment. The binary system encompassed Didymos, an asteroid measuring 760 meters, and its moonlet, Dimorphus, spanning roughly 150 meters. The difference in size enabled Dimorphus to assume a shorter orbital period, making observations more accessible and quantifiable.
After establishing a target, the DART scientists honed in on designing a spacecraft with technologies capable of altering Dimorphous’s path, creatively labeled the DART impactor. The DART Impactor weighed a mere 580 kilograms, carrying hydrazine propellant and xenon within its 1.8-meter by 1.9-meter by 2.6-meter frame to precisely maneuver the spacecraft into Dimorphus. Equipped with an imager, the Didymos Reconnaissance and Asteroid Camera for Optical navigation (DRACO) aimed to capture the spacecraft’s impact and broadcast it to Earth in high-resolution images.
On September 26, 2022, after rigorous testing and calculations, the DART impactor was set to collide with Dimorphus, seven million miles away from the Earth. Accelerating to a max speed of 6.1 kilometers per second, or 3.2 miles per second, the 580-kilogram DART impactor slammed itself into the five-billion-kilogram Dimorphus. The DRACO captured the entire event, broadcasting the successful impact to news networks millions of miles away. Alongside the impressive footage, the DART team dually noted that the impactor shortened Dimorphus’ orbital period by thirty-three minutes, a roughly five percent alteration from an impactor ten million times lighter. Upon this revolutionary discovery, the DART mission concluded that kinetic impactors can successfully alter the course of an asteroid.
The extent of DART’s impact goes beyond a literal one. In a chaotic deep space environment, asteroids assume sporadic paths that potentially end with a planetary impact. Prior to the DART mission, scientists could identify the asteroid courses dangerously near to Earth. However without any deflection technology, Earth remained defenseless against these bodies. Now, scientists possess adequate technology for the outer space equivalent of a “search and destroy” mission, locating and deflecting asteroids that pose a threat to the planet. In terms of the mission’s outcome, the Double Asteroid Redirection Test, literally and metaphorically, hit the bullseye on a planetary defense solution.
