How NASA Is Attempting To Redirect An Asteroid
There is a long list of possible threats that could have a major impact on Earth and the humans living on it. One of these threats includes an impact from a large asteroid. Large asteroids come close to Earth quite often. While the chances are still low for a major impact, NASA is working on technology that could help us if needed. This mission is called DART and stands for Double Asteroid Redirection Test.
There are a few parts of DART that are crucial in attempting to redirect an asteroid. These important features include DRACO, LICIACube, DART spacecraft itself, and additional technologies. All of which are necessary for impacting the asteroid as well as recording invaluable data. If successful, DART could provide reliable and crucial information that could end up having a big impact in the future.
NASA is capable of tracking large asteroids long before they get anywhere near Earth. With so many throughout the galaxy, they often pass by our planet a bit closer than what’s comfortable. This has encouraged NASA to try and figure out if we are capable of slightly changing the direction of an asteroid expected to hit Earth. This is the main goal of the DART mission.
DART Background
The Double Asteroid Redirection Test is being worked on by many different sections within NASA. DART is a planetary defense system testing the possibility of changing the orbit of an asteroid expected to hit Earth. The asteroid being targeted in the mission is not a threat to Earth. The asteroid DART is targeting is named Didymos. NASA points out that no known asteroid larger than 140 meters in size has a significant chance of hitting Earth within the next 100 years. However, only about 40 percent of those asteroids have been found.
The Didymos primary body is around 780 meters across but the secondary body or moonlet is about 160 meters in size. This is the more typical size of asteroids that could pose the most likely significant threat to Earth. Not only does DART have a lot of technology and features to help record the event, but NASA has very powerful telescopes tracking the asteroid now and when the expected impact happens. The DART spacecraft will be launching into space on top of SpaceX’s Falcon 9 rocket. This is a unique launch because of how far the payload will end up going. SpaceX often launches satellites and other technology into low Earth orbit such as Starlink but this will not be the case for DART. The mission is set to launch on November 24th, 2021, and impact the asteroid around September 2022.
How Does DART Work?
DRACO – The first feature of DART I want to highlight is DRACO. The DART payload consists of a single instrument the Didymos Reconnaissance and Asteroid Camera for Optical navigation or DRACO. This is a high-resolution imager derived from the New Horizons LORRI camera to support navigation and targeting. It’s important to point out that the mission is by no means easy. NASA is working to launch a satellite deep into space and hit a specific asteroid moving extremely fast. To make this possible the agency needed very complex and high-quality technology to track and help ensure DART hits the asteroid. DRACO also measures the size and shape of the asteroid to help determine the impact site and the geologic context. This piece of technology is just one part of the navigation system that is working to ensure DART is a success. However, the DRACO feature is not only for navigation but important data as well. DRACO will be streaming images all the way up until the impact with Dimorphos. This will provide NASA with valuable information and analytics for the mission that will be applied in the future.
LICIACube – The next interesting aspect of DART is the LICIACube. It stands for Light Italian CubeSat for Imaging of Asteroids. The DART spacecraft will deploy LICIACube roughly ten days prior to the expected impact on Dimorphos. Because of the early release prior to the impact, this piece of technology will have a perfect view of the impact. It will have some distance allowing the camera to capture images of not only the collision but the resulting ejecta cloud, and potentially a glimpse of the impact crater. The design is based on two main instruments. The first is a narrow field panchromatic camera meant to acquire images from long distances with a high spatial resolution named LEIA. The second is a wide field RGB camera, allowing a multicolor analysis of the asteroidal environment called LUKE. Together they are planning to provide additional one-of-a-kind images that NASA can use to help determine the effectiveness of this test along with even more information.
DART Spacecraft – Another part of the DART mission that I want to mention is the spacecraft itself. NASA has worked to make the DART spacecraft low-cost. The main structure of the spacecraft is a box with dimensions of roughly 1.2 by 1.3 by 1.3 meters. In addition to the box, there are large solar panels as well. These solar panels roll out after launch and have some unique technology in them. Specifically, the solar panels use flexible and rollable wings which are lighter and more compact than traditional solar arrays. The DART spacecraft will navigate and crash itself into Dimorphos at a speed of 6.6 kilometers a second. Altogether DART weighs around 1340 pounds or 610 kilograms. This extremely high speed along with the heavy mass is expected to slightly change the orbit of an asteroid.
Additional Technology – I mentioned prior a lot of main components of the DART mission. While these are very important there is also a lot of extra technology within the spacecraft that are helping to guide, power, move, and hit the target asteroid. One of these parts is the GNC and SMART Nav. NASA points out that the hardest part of the mission is targeting and then hitting the correct asteroid. This is why there are so many pieces of DART working on this aspect of the mission. Another example of this is the GNC and SMART Nav. This autonomous optical navigation system will identify and distinguish between the two bodies at Didymos and then, working in concert with the other GNC elements, directs the spacecraft toward the smaller body, Dimorphos, all within roughly an hour of impact. Another unique piece of technology is advanced ion propulsion. This is a solar-powered electric propulsion system working to move and speed up the DART spacecraft. The final part of DART I want to mention is the Radial Line Slow Array. This low-cost, high-gain antenna enables high-efficiency communications in a compact, planar form. This offers the unique opportunity to both send and receive data. All of which is necessary for the DART mission.
Conclusion
NASA is constantly tracking asteroids that are anywhere near Earth. Throughout time there have been some that come very close. It’s possible that sometime in the far future, an asteroid is expected to hit Earth. For this reason, NASA is working on the DART mission to launch and hit an asteroid slightly off course. The DART mission consists of DRACO, LICIACube, DART spacecraft itself, and additional technologies. All of which work together to find, capture, target, and hit the asteroid. If successful this mission will provide NASA with extremely valuable information in the future that could help redirect an asteroid headed for Earth.
