DART: What is NASA’s mission to drill asteroids?

NASA is ready to launch its long-awaited mission to test whether it is possible to deflect an incoming asteroid.

But what does the DART mission entail? When will it launch and how long will it take?

Here you will find everything you need to know about the DART mission.

What is DART?

the DART mission seeks to launch a specially designed rocket to alter the trajectory of an asteroid.

In simple terms, it means hitting an asteroid with a rocket with enough speed to change its direction by a fraction of a percent, although NASA has also described it as essentially a “pillow fight in microgravity.”

The technology involved includes what is called the “kinetic impactor” technique, which should be able to change the motion of an asteroid in space.

A spacecraft will crash directly into an asteroid at a speed of around 6.6 kilometers per second, which should force it to change the speed of its orbit. It will only change it by a fraction of a percent, but it is enough to be observed and measured by astronomers with telescopes.

It is the first attempt at demonstration of the kinetic impactor technique.

An artist’s rendering of the cosmic collisions surrounding a sun-like star. (credit: REUTERS / Gemini Observatory / Jon Lomberg / Handout MR / CP)

Which asteroid is the objective of the mission?

DART is set to fly Didymos binary asteroid system. This system consists of two asteroids, 65803 Didymos, which is around 780 meters in diameter (twice the size of the Empire State Building), and Dimorphos, which is around 170 meters in diameter (about the size of the Washington Monument). Of the two, Dimorphos will be the specific target.

There is no risk of Didymos or Dimorphos hitting Earth anytime soon, and their orbit around the sun does not cross Earth’s orbit. As such, it is an ideal test.

What is the DART spacecraft?

The DART craft itself is relatively simple and inexpensive when it comes to spacecraft.

The spacecraft is essentially a 1.2 x 1.3 x 1.3 meter box, with other structures extending it. In total, it measures 1.8 meters wide, 1.9 meters long and 2.6 meters high. Its solar panels will stretch it even further, as each one measures 8.5 meters.

The spacecraft has a mass of about 610 kilograms, but on impact it will have a mass of 550 kilograms. It carries around 50 kilograms of thruster for maneuvering and attitude control and 60 kilograms for propulsion, although it will use only 10 kilograms of the latter.

It has a single instrument known as the Didymos Reconnaissance and Asteroid Camera for Op-nav (DRACO), which is designed to help the spacecraft navigate and provide images. However, it also comes equipped with Roll-Out Solar Arrays (ROSA), which will be used to power NASA’s Evolutionary Xenon Thruster – Commercial (NEXT-C) solar electric propulsion system.

It will be launched by a SpaceX Falcon 9 rocket, from where it will eventually separate.

Why do we need the DART mission?

Simply put, asteroids are dangerous.

An asteroid impact is one of the biggest possible natural disasters that could occur. The danger of even the smallest is well known to experts, and space agencies around the world monitor potential catastrophic impacts, as well as investigating possible means to stop them.

    An asteroid is seen crashing into Earth in this artist's rendering of an asteroid impact.  (credit: PIXABAY) An asteroid is seen crashing into Earth in this artist’s rendering of an asteroid impact. (credit: PIXABAY)

NASA tracks all near-Earth objects (NEOs) that are detected, with particular attention to those considered potentially Hazeroud asteroids (PHAs), all of which are at least 140 meters in diameter. These are the ones that could cause catastrophic damage to the planet after impact.

But even the little ones can be dangerous.

The last known significant impact of an asteroid was on February 15, 2013, when an asteroid exploded in midair over Chelyabinsk, Russia. This asteroid was only 17 meters wide, and while it did not cause casualties, the shock wave from the explosion shattered windows in six different Russian cities and caused 1,500 people to need medical attention.

The older ones pass the planet frequently; some have even gotten very close.

Is DART defective?

One big problem with DART is how long it took for the mission to take off. As such, it could mean a tighter time frame when dealing with impending disaster.

Are there other options besides DART?

Technically, yes.

As for deflection, the Airbus company proposed another model in July 2021. Essentially, this method is a more ad hoc means of deflecting asteroids.

It relies on reusing television satellites in orbit around the planet, essentially hijacking them and using them to deflect incoming asteroids, should the need arise.

The science behind this method seems solid, although it also has its flaws, such as being able to deflect the asteroid when it is far enough away from the planet, which could hypothetically be more than six months away.

Other methods focus on disruption: that is, destroying the asteroid, especially with a nuclear weapon. This is the type of method most commonly seen in pop culture and is a staple of science fiction movies. However, it has many problems and it is one of the main things that the DART Mission is trying to avoid.

It was often feared that the use of nuclear weapons would cause fragments of the asteroid to fall on Earth and cause serious damage anyway, although some recent studies have shown that this may be a better alternative than previously thought. However, it would also take time.

    Asteroid impact: how can we prevent one from happening?  (credit: PIXABAY) Asteroid impact: how can we prevent one from happening? (credit: PIXABAY)

The fragments would then spread out in a cloud of fragments and, if not completely deviated from their course, would head into Earth’s atmosphere at speeds of around Mach 60.

But this is where Earth’s atmosphere kicks in, as entering the atmosphere at such a high speed causes it to experience severe levels of heat and pressure. These stresses, in turn, would cause the fragments to explode even more, creating a kind of sonic boom.

This may seem scary to some, because, as the scientists involved in the study pointed out, it would appear similar to a thermonuclear bomb explosion. But it would only be a large, harmless “sound and light” show, so there is no risk of nuclear radiation. The dust might still be present, but it would not be catastrophic enough to cause a global climate disaster scenario.

When is the DART mission launched?

DART is currently scheduled to launch at 1:20 am EST on November 24, 2021.

Stay tuned to find out more!


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