NASA’s DART mission

NASA’s DART mission

Subject – Science and Tech

Context – On November 24, at around 11.50 am (IST), NASA will launch the agency’s first planetary defence test mission named the Double Asteroid Redirection Test (DART)

Concept –

• The main aim of the mission is to test the newly developed technology that would allow a spacecraft to crash into an asteroid and change its course.
• The spacecraft will be launched on a SpaceX Falcon 9 rocket from Vandenberg Space Force Base in California.
• The target of the spacecraft is a small moonlet called Dimorphos (Greek for “two forms”). It is about 160-metre in diameter and the spacecraft is expected to collide when it is 11 million kilometres away from Earth.
• Dimorphos orbits a larger asteroid named Didymos (Greek for “twin”) which has a diameter of 780 metres.
• The asteroid and the moonlet do not pose any threat to Earth and the mission is to test the new technology to be prepared in case an asteroid heads towards Earth in the future.
• The spacecraft will navigate to the moonlet and intentionally collide with it at a speed of about 6.6 kilometres per second or 24,000 kilometres per hour. The collision is expected to take place between September 26 and October 1, 2022.
• It is a suicide mission and the spacecraft will be completely destroyed.
• The spacecraft also carries about 10 kg of xenon which will be used to demonstrate the agency’s new thrusters called NASA Evolutionary Xenon Thruster–Commercial (NEXT-C) in space.
  • NEXT has very high fuel efficiency and flexible operations making it ideal for many classes of science missions.

Why Dimorphos?

• Didymos is a perfect system for the test mission because it is an eclipsing binary which means it has a moonlet that regularly orbits the asteroid and we can see it when it passes in front of the main asteroid.
• Earth-based telescopes can study this variation in brightness to understand how long it takes Dimorphos to orbit Didymos.
• The timing for the DART impact is when the Didymos system is closest to the Earth. So the telescopes can really make the most precise measurement possible.