From this distance—about 20 million miles away from DART—the Didymos system is still very faint, and navigation camera experts were uncertain whether DRACO would be able to spot the asteroid yet. However, 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 a test to prove our imaging techniques,” said Elena Adams. She is the DART mission systems engineer at the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland. “The quality of the image is similar to what we could obtain from ground-based telescopes, but it is important to show that DRACO is working properly and can see its target to make any adjustments needed before we begin using the images to guide the spacecraft into the asteroid autonomously.”
A number of navigation simulations using non-DRACO images of Didymos have already been conducted by the team. However, DART will ultimately depend on its ability to see and process images of Didymos and Dimorphos, once it too can be seen, to guide the spacecraft toward the asteroid, especially in the final four hours before impact. At that point, DART will need to autonomously self-navigate to impact successfully with Dimorphos without any human intervention.
“Seeing the DRACO imagery of Didymos for the first time allowed us to determine the optimal settings for DRACO and fine-tune the software,” said Julie Bellerose, director of DART navigation at NASA’s Jet Propulsion Laboratory in Pasadena, California. “In September, we will refine DART’s goals by more precisely pinpointing the location of Didymos.”
Using observations made every five hours, the DART team will perform three trajectory corrections over the next three weeks. Each of these will further reduce the margin of error for the spacecraft’s desired trajectory impact. After the final maneuver on September 25, about 24 hours before impact, the navigation team will know the location of the target Dimorphos within 2 kilometers (1.2 miles). From there, DART will guide itself to intercept the asteroid moon. DART will hit Dimorphos at 4 miles (7 kilometers) per second.
DRACO subsequently observed Didymos during planned observations on Aug. 12, Aug. 13, and Aug. 22.
The Johns Hopkins Applied Physics Laboratory (APL) manages NASA’s Planetary Defense Coordination Office’s DART mission as a program of the agency’s Planetary Mission Program Office. DART, the world’s first planetary defense test mission, deliberately performed kinetic shocks on Dimorphos to slightly alter its motion in space. While asteroids don’t pose any threat to Earth, the DART mission will demonstrate that spacecraft can autonomously navigate to kinetic impacts on relatively small asteroids, and demonstrate that this is a viable technology for colliding with Earth. mid-deflection asteroid. always be found. DART will reach its goal on September 26, 2022.