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The DART mission, to test our ability to assassinate the threat of an incoming asteroid collision, has it’s eye on the moonlet Dimorphos. The idea isn’t to obliterate the hunk of rock, merely bump it hard enough to nudge it safely off to one side. This test objective isn’t close to being a threat to Earth but it is great for target practice. NASA can test the idea and see if it will work when we really need it.
DART has eye on target
DART has it’s electric eye on the moonlet Dimorphos, along with the chunk of space debris it orbits, Didymos. At this point they both look like a single point of light but that’s okay.
The important thing is that the camera can be calibrated to make it more accurate as the kamikaze test probe gets closer. The Double Asteroid Redirection Test craft just phoned home with its first snapshot from the far reaches of space.
Planetary defense is something which the human race only recently started taking seriously. Amateur astronomers playing with equipment which is obsolete by modern standards keep spotting asteroids flying toward us from directions where we haven’t been looking. Some of them could do serious damage.
That’s where DART comes in. The time to find out if a small impact while the incoming threat is still far away is enough to deflect the mass from Earth’s path.
“If proven effective, this spacecraft design could potentially be scaled up to deflect an Earth-bound asteroid.” The image beamed back is actually a “composite of 243 individual images.”
Because it’s on a suicide mission, DART is stripped to the bare basics. The only instrument it has on board is the Didymos Reconnaissance and Asteroid Camera for Optical Navigation. They call it DRACO. This image was taken from 20 million miles away, so the detail isn’t that impressive.
Prove our imaging techniques
According to DART mission systems engineer Elena Adams of the Johns Hopkins University Applied Physics Laboratory in Maryland, this “first set of images is being used as a test to prove our imaging techniques.”
“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.” That is when the fun starts
Once it gets going, “DART will use DRACO to navigate to its impact site completely independently of its Earth-based controllers.” It’s not ready for the training wheels to come off yet though. “For now, humans are in charge.”
The plan for the next three weeks is to take an image every five hours. They can use those to “make a series of three trajectory correction maneuvers.” That will put the asteroid killer “on a precise path to Didymos.” The last 24 hours before impact, the craft will have full autonomous control.
“Seeing the DRACO images of Didymos for the first time, we can iron out the best settings for DRACO and fine-tune the software,” Julie Bellerose, the DART navigation lead at NASA’s Jet Propulsion Laboratory in California, relates.
“In September, we’ll refine where DART is aiming by getting a more precise determination of Didymos’ location.” Set your alerts for September 26 at 7:14 p.m. EDT. That’s when the big finale happens.
