The Didymos Reconnaissance and Asteroid Camera for Optical navigation (DRACO) aboard NASA’s Double Asteroid Redirection Test (DART) spacecraft has captured the new images of the binary, near-Earth asteroid system Didymos, composed of the roughly 780-m- (2,560-foot) diameter Didymos and the smaller, approximately 160-m- (530-foot) size moonlet Dimorphos. On September 26, 2022, DART will impact Dimorphos to change its orbit within the binary system.
This image of the light from asteroid Didymos and its orbiting moonlet Dimorphos is a composite of 243 images taken by the DRACO camera on board NASA’s DART spacecraft on July 27, 2022. Image credit: NASA / JPL / DART Navigation Team.
“This first set of images is being used as a test to prove our imaging techniques,” said DART mission systems engineer Dr. Elena Adams, a researcher at the Johns Hopkins Applied Physics Laboratory.
“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.”
The new image of the Didymos asteroid system is a composite of 243 images taken by the DRACO camera on July 27, 2022.
From this distance — about 32 million km (20 million miles) away from DART — Didymos is still very faint, and navigation camera experts were uncertain whether DRACO would be able to spot the asteroid yet.
But once the 243 images DRACO took during this observation sequence were combined, Dr. Adams and her colleagues were able to enhance it to reveal Didymos and pinpoint its location.
“Seeing the DRACO images of Didymos for the first time, we can iron out the best settings for DRACO and fine-tune the software,” said DART navigation lead Dr. Julie Bellerose, a researcher at NASA’s Jet Propulsion Laboratory.
“In September, we’ll refine where DART is aiming by getting a more precise determination of Didymos’ 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 target Dimorphos within 2 km (1.2 miles).
From there, DART will be on its own to autonomously guide itself to its collision with the asteroid moonlet.
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This article is based on text provided by the National Aeronautics and Space Administration.
Source link: https://www.sci.news/astronomy/didymos-images-11174.html
