CLARKSBURG, W.Va. (WBOY) — NASA’s latest mission seeks to answer the question “Can we protect the earth from life-threatening asteroids?”
Below you can see the final images taken from the DART mission in its last moments before impact. If you want to learn more about NASA’s first mission to redirect an asteroid, you can read the full article below.
DART or Double Asteroid Redirection Test, is mankind’s first attempt at altering the trajectory of an asteroid. On Monday, DART successfully made contact with the asteroid, but we won’t know the extent of the change in Dimorphos’ orbital trajectory for a few more weeks.
The target of this experiment was the double asteroid Didymos, more specifically its moon Dimorphos. Didymos is about as tall as the world’s tallest building, the Burj Kalifa, weighing in at a modest 52.7 billion kilograms, but the target Dimorphose measures in at around 520 feet across. DART’s objective, is to slightly shift the orbital path of Dimorphos around its parent asteroid as a proof of concept and test for asteroid redirection techniques.
Dimorphos is approximately 6.7 million miles from earth, making it a prime candidate for this experiment — far enough not to pose any risk to earth, but close enough to monitor any changes to its orbit from observatories on earth.
According to Eric Ianson, Deputy Director of Planetary Science at NASA headquarters, work on this project began over eight years ago in partnership with the Italian Space Agency. The actual spacecraft, DART was launched in November of last year.
DART is being accompanied by a smaller “Cubesat,” designed by the Italian Space Agency, that separated from the main craft about two weeks ago, and will attempt to capture footage and photographs of the impact and debris. The European Space Agency is also planning a follow-up mission to observe the subsequent crater and DART’s effect on the asteroid.
At the moment of impact, DART will be traveling at approximately four miles (or six kilometers) per second, way too fast for any human control over the craft to be feasible. Because of these insane speeds, DART will be using a first-of-its-kind, onboard and autonomous navigation system called SMART Nav that will allow the craft to make decisions and course correct on its own based on a set of algorithms.
“With SMART Nav, it’s no longer about just keeping the spacecraft in a prescribed orientation or carrying out correction maneuvers. It’s about conducting the entirety of the last four hours of the mission without any human intervention”, said Mark Jensenius, a guidance and navigation control engineer on the SMART Nav team at the Johns Hopkins Applied Physics Laboratory.
While it sounds high-tech, the actual SMART Nav unit is about as powerful as an original Playstation from 1994 and pales in comparison to the smartphone or computer you’re reading this story on. The reason being the more complex you make your computer chip, the more likely it is to be affected by radiation out in space.
In order to make its adjustments, SMART Nav uses a camera called the Didymos Reconnaissance and Asteroid Camera for Optical navigation, or DRACO to its friends. DRACO essentially functions as the eyes for DART by locating the asteroids and sending images of them to SMART Nav, which then uses those images to make any necessary adjustments to achieve an impact.
However, in order for DART to be able to collect data prior to its impact with Dimorphos, such as where exactly DART hits, the craft will have to stop maneuvering two minutes before impact. This is because when the thrusters are active, they cause movement in the craft, causing the DRACO camera to produce blurry images that are good enough for SMART Nav, but not great for scientific observation.
Unfortunately, when dealing with speeds upwards of 14,000 mph, even the slightest movement could cause DART to miss entirely.
“It’s as if we were over the Indy 500 when we stop maneuvering, and then we simply have to coast all the way to Baltimore, and we have to land inside Camden Yards,” Jensenius said.
So why are we bothering to attempt this experiment if it’s far enough away that it isn’t a threat?
Eric Ianson said in an interview with 12 News that over 100 tons of extraterrestrial material fall to earth daily, and while a lot of it is dust or gets burned up entering earth’s atmosphere we do get larger objects as well. There are currently about 1,000 objects near (relatively) earth that are considered hazardous, more than one kilometer across. About half of them have been identified and are not a threat, but the other half, the unidentified half, are the ones that could be dangerous.
“Maybe one every 20,000 years hits earth, but it doesn’t run on a clock. It’s not like, say, ‘we had one 15,000 years ago so we have another 5,000 years to go,’ it doesn’t work that way, it could be any time. So while we’re not concerned that there’s an imminent threat, we also want to be prepared in case a situation does present itself.”
Ianson said the biggest challenge to the project has been its sheer complexity. Despite all the work that has been done up to this point, Dimorphos is dim enough and far away enough that we still have no idea what it even looks like; we only know it’s there because of the dimming on the main asteroid Didymos.