The DART Spacecraft of NASA Aims for an Asteroid

Sep, 2022 - By SMI

Didymos, the double-asteroid system that contains its target, Dimorphos, was just captured in the first photograph taken by NASA's Double Asteroid Redirection Test (DART) probe. 

On September 26, DART will deliberately crash with Dimorphos, the moonlet of the asteroid Didymos. This is humanity's first attempt to use a spacecraft to divert an asteroid for planetary defense, even though the asteroid presents no threat to Earth.

This composite of 243 photos was created on July 27, 2022, by the Didymos Reconnaissance and Asteroid Camera for Optical Navigation (DRACO) onboard DART. It shows the light from the asteroid Didymos and its orbital moonlet Dimorphos.

The Didymos system is still quite weak from this distance—roughly 20 million miles from DART—and navigation camera scientists weren't sure if DRACO would be able to see the asteroid yet. However, by combining the 243 photos that DRACO captured during this observation series, the team was able to improve it and discover Didymos and identify its precise position.

This initial set of photographs, according to Elena Adams, "is being used as a test to build our imaging methodologies." She is a DART mission systems engineer at the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland (APL). The image quality is equivalent to what we might acquire from ground-based telescopes, but it's important to show that DRACO is working properly and detecting its target before utilising the photos to steer the spacecraft into the asteroid on its own.

In a number of earlier navigation simulations, the researchers employed Didymos images from sources other than DRACO. DART's ability to guide the spacecraft toward the asteroid ultimately depends on its capacity to see and analyse images of Didymos and Dimorphos once it too can be discovered, especially in the last four hours before impact. Then, without assistance from humans, DART must perform its own manoeuvres to successfully crash with Dimorphos.