Spaceship NASA’s Double Asteroid Redirection Test (DART) recently saw for the first time Didymos, the double asteroid system that includes its target, Dimorphos. On September 26, DART will intentionally crash into Dimorphos, the small moon of asteroid Didymos.
Although the asteroid does not pose a threat to Earth, this is the world’s first test of the kinetic impact technique, using a spaceship to deflect an asteroid for planetary defense.
This image of light from the asteroid Didymos and its orbiting moon Dimorphos is a composite of 243 images taken by the Didymos Asteroid Reconnaissance Camera and for optical navigation (DRACO) on July 27, 2022.
From this distance, about 20 million miles from DART, the Didymos system is still very weak and navigation camera experts were not sure if DRACO could detect the asteroid yet. But once the 243 images DRACO took during this observation sequence were combined, the team was able to enhance it to reveal Didymos and pinpoint its location.
“This first set of images is being used as evidence to test our imaging techniques”, said in a statement Elena Adams, a DART mission systems engineer at the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland. “The image quality is similar to what we could get from ground-based telescopes, but it is important to show that DRACO is working properly and can see its target to make any necessary adjustments before we start using the images to guide the spacecraft. on the asteroid autonomously.”
Although the team has already run a number of navigation simulations using non-DRACO images of Didymos, DART will ultimately rely on its ability to view and process images of Didymos and Dimorphos, once they can also be seen, to guide the spaceship towards the asteroid. , especially in the last four hours before impact. At that moment, DART will need to navigate itself to successfully impact Dimorphos without any human intervention.
“By seeing the DRACO images from Didymos for the first time, we can define the best settings for DRACO and fine-tune the software,” said Julie Bellerose, DART navigation lead at the NASA’s Jet Propulsion Laboratory in Pasadena, California. “In September, we will refine where DART is headed by getting a more precise determination of Didymos’s location.”.
Using observations taken every five hours, the DART team will execute three trajectory correction maneuvers over the next three weeks, each of which will further reduce the margin of error for the spacecraft’s required trajectory to impact.
After the final maneuver on September 25, approximately 24 hours before impact, the navigation team will know the position of the Dimorphos target within a radius of 2 kilometers. From there, DART will be on its own to guide itself autonomously to its collision with the asteroid’s small moon.
DRACO subsequently observed Didymos during scheduled observations on August 12, 13, and 22.
Johns Hopkins APL manages the DART mission for the NASA Planetary Defense Coordination Office as a project of the agency’s Planetary Missions Program Office.
DART is the world’s first planetary defense test mission, intentionally executing a kinetic impact on Dimorphos to slightly change its motion in space. While the asteroid poses no threat to Earth, the DART mission will demonstrate that a spacecraft can autonomously navigate to a kinetic impact on a relatively small asteroid and demonstrate that this is a viable technique for deflecting an asteroid on a collision course. with Earth if one is ever discovered. DART will reach its goal on September 26, 2022.