NASA’s DART to change the course of an asteroid – and history

24 Nov 2021

Illustration of DART and LiciaCube prior to impact with Dimorphos. Image: © NASA/Johns Hopkins APL/Steve Gribben

NASA’s DART spacecraft launched today will collide with an asteroid to see if its orbit can be changed.

For the first time, humans are trying to change the course of an asteroid to see if potential collisions with Earth can be prevented in the future. Leading the way is NASA with its Double Asteroid Redirection Test (DART), which launched early this morning (24 November).

DART, riding with a one-way ticket on SpaceX’s Falcon 9 rocket, left from California and is now heading towards a 160-metre space rock called Dimorphos. The aim is to collide with the asteroid and slightly change its orbit.

Dimorphos is not considered a threat to Earth and is being used merely as an experiment. If successful, the mission will prove that it is possible to change the collision course of an object that may be headed towards Earth in the future.

“DART is turning science fiction into science fact and is a testament to NASA’s proactivity and innovation for the benefit of all,” said NASA administrator Bill Nelson. “In addition to all the ways NASA studies our universe and our home planet, we’re also working to protect that home.”

While there are no known asteroids on a collision course with Earth in the near future, even objects a few hundred metres in diameter could cause worldwide damage upon impact. Changing an object’s course by even a tiny bit can prevent a collision.

“Our goal is to find any possible impact, years to decades in advance, so it can be deflected with a capability like DART that is possible with the technology we currently have,” said Lindley Johnson, planetary defence officer at NASA.

European contribution

About 10 days before DART makes contact with Dimorphos, a small Italian satellite called LiciaCube will be deployed from the spacecraft to capture images of the impact and the resulting cloud of ejected matter. LiciaCube is a cubesat developed by the Italian Space Agency.

The European Space Agency (ESA) will have a role to play in the endeavour, too. Four years after DART’s impact with Dimorphos, the ESA’s Hera project will dart to the same asteroid to conduct detailed surveys.

“At its core, DART is a mission of preparedness, and it is also a mission of unity,” said Thomas Zurbuchen, associate administrator for the Science Mission Directorate at NASA, speaking of the international collaboration between NASA, Italy’s space agency and the ESA.

Hera, named after the Greek goddess of marriage, will focus on the crater left by DART’s collision and attempt to determine the internal structure and precise mass of Dimorphos post-impact. Hera is expected to launch in November 2024 and begin its work in late 2026.

“I’m extremely happy to see the DART mission on its way,” said Ian Carnelli, project manager of Hera. “Great work from NASA, SpaceX and the Applied Physics Laboratory teams – they make it look easy!”

The Hera spacecraft is currently being built in Germany while some of its other essential parts, such as its navigation system and radar, are being built and tested in Spain and the Netherlands.

“It is an indescribable feeling to see something you’ve been involved with since the ‘words on paper’ stage become real and launched into space,” said Andy Cheng, one of the investigation leads at Johns Hopkins Applied Physics Laboratory who came up with the idea of DART.

“This is just the end of the first act, and the DART investigation and engineering teams have much work to do over the next year preparing for the main event – DART’s kinetic impact on Dimorphos. But tonight, we celebrate!”

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Vish Gain is a journalist with Silicon Republic