NASA’s robots for deep space exploration are engineering marvels that are often built to last. you have. , dancing around the sun, wielding an epic heat shield that will keep it running for years. and Lucy, on a mission to visit a handful of space rocks over the next 12 years.
Then you have DART.
DART (Double Asteroid Redirection Test) is not destined by decades of solar system science. The spacecraft was launched in November 2021, and by this week, it won’t be.
DART is NASA’s pilot for a planetary defense system that aims to push incoming asteroids away from Earth – by literally smashing spacecraft into them.
Asteroids ranging in size from refrigerators to cars,. Fortunately, they are not very dangerous because most of the rocks burn in the Earth’s atmosphere. But about 66 million years ago, as you might remember, the dinosaurs were wiped out by a massive space rock by the name of Chicxulub.
The goal of the DART mission is simple: NASA wants to understand if we can collide with an asteroid to prevent such a catastrophe from eliminating humans as well.
As a proof of principle, on Monday, September 26, the spacecraft will hit a small asteroid called Demorphos that orbits a larger asteroid, Didymus. The DART spacecraft is preparing to navigate autonomously toward and collide with Dimorphos when it is about 7 million miles from Earth – its closest point to Earth. The target asteroid is as large and tall as the Washington Monument, and upon impact the team behind DART hopes that the rocks’ path and speed will change.
This floating rock does not pose a threat to our planet. But if DART keeps Demorphos off a bit, we’ll know we might have a practical one-day tactic to fend off truly dangerous asteroids.
Acquired Target: Dimorphos
Sailing across our solar system is a gray space rock about half a mile wide known as Didymus, which, with the gentle force of gravity, keeps a companion asteroid on a leash. This second smaller segment that revolves around Didymus is the target of DART: Dimorphos.
The scientists behind DART chose Demorphos for testing because its orbit around Didymus simulates how potentially threatening near-Earth asteroids orbit the Sun. Asteroids are gravitationally bound to our star, which could put it on a collision course with Earth.
But Demorphos’ orbit is not confined to Earth or the Sun, but to Didymus. This makes it an ideal testing ground for NASA. They can try to smash DART into the little rock and see how that changes its orbit around its larger companion.
NASA predicts that the crash will be powerful enough to adjust the orbital period of Demorphos by a few minutes. Calculations show that the effect will bring Dimorphos closer to Didymus.
The message we’re taking home is that this is a technical demonstration — a way for NASA to get valuable data on how we might one day shove a very scary asteroid onto a collision course with Earth. The scientists behind the mission want to know how much we can affect the orbits of the asteroids by crashing a spacecraft just barely pushing the rock.
“Mostly, what we’re looking to do is change the velocity of the incoming object by a centimeter per second or so. That’s not very fast, but if you do it seconds before enough, you can cause it to lose ground completely,” according to a mission review by the Physics Lab. Applied Johns Hopkins University.
This approach – one of many ideas to save humanity from asteroids – is known as ‘Kinetic Collider Deflection’. According to the team, this is the first time the method has been used between galaxies.
“This technology is believed to be the most technologically mature approach to mitigating the impact of a potentially dangerous asteroid,” Lindley Johnson, NASA’s planetary defense officer, said in a statement. “Planetary defense experts will help improve computer models of the kinetic coincidence of planets, giving insight into how to transform potentially dangerous NEOs in the future.”
The way it works is very intuitive.
Quick, throw something at him!
Let’s say your friend is riding a skateboard very fast and heading towards your dog. One (messy) way for you to save your dog is to bump into your skater friend. When you bump into your friend, the energy you built changes its direction and reduces its speed. You have just become a motion effect, designed to throw your skateboarding friend off the track and save your dog.
DART works in a similar way, but it’s not trying to protect any canines, it’s just trying to get the skater off course. The spacecraft, which is about the size of a school bus, will fly to Demorphos at about 4.1 miles per second. That’s roughly 14,760 miles per hour (23,760 kilometers per hour).
NASA says that upon impact, the orbital velocity of the small asteroid or small moon should change by a fraction of a percent, resulting in an orbital period that is several minutes slower.
Although Dimorphos poses no threat to Earth, ground-based telescopes can easily classify the impacts of the outcrop, because at just 7 million miles away, the impact is close enough for scientists to notice any changes in the rock’s orbit around its companion. This will help scientists master future planetary defense weapons based on valuable information retrieved from the DART prototype.
Courageous specifications of the spacecraft
DART is rather simple. It’s a relatively inexpensive metal box with two power extendable solar arrays, one camera and a smaller satellite, or CubeSat, that will be deployed just before the impact. The limited number of tools makes sense, because the spacecraft is doomed to die on a suicide mission.
Here are some details about the DART spacecraft:
cost: $308 million.
Weight: 1,345 lb (610 kg) at launch / 1,210 (550 kg) at impact.
Box Dimensions: 3.9 x 4.3 x 4.3 feet (1.2 x 1.3 x 1.3 metres).
Solar array dimensions: 27.9 ft (8.5 m).
Additional devices: DRACO camera and CubeSat one.
engine: Ion propulsion technology / xenon drives.
While the payload of the DART spacecraft is extremely small, the programming of the team behind the course is very advanced. That’s because the brave little craft will act independently throughout the mission.
To the end, DART
The spacecraft’s tools may be few, but they are essential. The Didymos Camera for Reconnaissance and Asteroid Camera for Optical Navigation, or Draco, is an ultra-high-resolution camera that can measure the size, shape, and composition of geological asteroids in their vicinity.
DART also contains a metal oxide semiconductor and an image processor that helps the spacecraft determine the exact location of the Dimorphos and stream information back to Earth in real time via an antenna attached to the device.
In addition, DART will be equipped with a suite of navigational tools with the latest directional coding, including a star tracker, my favorite NASA tool, to make sure it hits Demorphos at just the right moment – ding, ding: 7 million miles (11 million km) barrier . Ten days before DART hits its target, it will send a CubeSat. This branch will maintain the kinetic effect record long after DART has been reduced to rubble.
DART will do its duty to the end. NASA hopes to get the exciting details of the collision before, during, and after the impact, so “in its final moments,” says the Johns Hopkins University overview, “DART’s DRACO camera will help characterize the impact site by providing high-resolution scientific images of Dimorphos’ surface.”
This piece was originally published when DART was launched in November 2021.