Two weeks ago, the Double Asteroid Redirection Test (DART) mission struck its target with a small satellite in what is known as a kinetic impact, paving the way for future active planetary defense missions. DART included a camera, Didymos Reconnaissance and Asteroid Camera for Optical navigation (DRACO), piloted by a sophisticated onboard auto-navigation system, Small-Body Maneuvering Autonomous Real-Time Navigation (SMART Nav). DART was sent to Didymos, the 780-meter-in-diameter asteroid in the asteroid belt, and struck its 160-meter-in-diameter moonlet, Dimorphos. The mission’s primary goal was to change the orbital period of Dimorphos, the time it takes the moon to orbit Didymos. Initial measurements of the system post-impact show Dimorphos’ orbit has been altered from 11 hours and 55 minutes to 11 hours and 23 minutes, 32 minutes shorter.
DART was highly successful by all metrics. Because communications between mission control at Johns Hopkins University and the DRACO spacecraft in the asteroid belt took up to 38 seconds, a significant component of the mission was developing the SMARTNav system to pilot the spacecraft’s final approach. The system worked flawlessly during the last 90,000 kilometers of DRACO’s journey, initially piloting the spacecraft toward Didymos and eventually to its intended target Dimorphos.
Following the DART impact, measurements taken by the companion Italian spacecraft, Light Italian CubeSat for Imaging of Asteroids (LICIACube), will be analyzed to interpret the resulting crater on Dimorphos. The surfaces of small asteroids are generally thought to be loosely compacted masses of dust, pebbles, and boulders, but the internal structures of asteroids largely remain unknown. The DART impact and subsequent LICIACube high-resolution images provide an unprecedented view into how small asteroids are held together and ultimately how they are disrupted during an impact event. READ MORE