<p>A comet flying in the sky</p>

A comet flying in the sky

Nasa to test Earth’s defences against killer asteroids by slamming spacecraft into a rock

Andrew Griffin
Tuesday 23 November 2021 09:54
Comments

Nasa is to slam a spacecraft into an asteroid in a test of whether it would be able to keep humanity safe from a killer object coming to Earth.

This week, it will launch the mission that will see the spacecraft attempt to redirect in an asteroid – as preparation for a time when such a precaution might be needed.

The double asteroid redirection test (Dart) will test defence technologies for preventing a hazardous asteroid impacting Earth.

It aims to prove that a spacecraft can autonomously navigate to a target asteroid and intentionally collide with it - called a kinetic impact - at roughly four miles per second (six kilometres per second).

The collision will change the speed of the moonlet in its orbit around the main body by a fraction of 1%.

But this will change the orbital period of the moonlet by several minutes - enough to be observed and measured using telescopes on Earth.

Dart’s target is not a threat to Earth, and is the asteroid moonlet Dimorphos (Greek for two forms), which orbits a larger asteroid named Didymos (Greek for twin).

Nasa says this system is a perfect testing ground to see if intentionally crashing a spacecraft into an asteroid is an effective way to change its course, should an Earth-threatening asteroid be discovered in the future.

While no known asteroid larger than 140 metres in size has a significant chance of hitting Earth for the next 100 years, only about 40% of those asteroids have been found as of October 2021.

Dart is scheduled to launch no earlier than 6.20am on November 24 on a SpaceX Falcon 9 rocket from Vandenberg Space Force Base in California, in the US.

Once launched, Dart will deploy roll out solar arrays (Rosa) to provide the solar power needed for its electric propulsion system.

The spacecraft will demonstrate the Nasa evolutionary xenon thruster - commercial (Next-C) solar electric propulsion system as part of its in-space propulsion.

The system is based on the Dawn spacecraft propulsion system, and was developed at Nasa‘s Glenn Research Centre in Cleveland, Ohio, in the US.

By using electric propulsion, Dart could benefit from significant flexibility to the mission timeline.

Additional reporting by Press Association

Register for free to continue reading

Registration is a free and easy way to support our truly independent journalism

By registering, you will also enjoy limited access to Premium articles, exclusive newsletters, commenting, and virtual events with our leading journalists

Please enter a valid email
Please enter a valid email
Must be at least 6 characters, include an upper and lower case character and a number
Must be at least 6 characters, include an upper and lower case character and a number
Must be at least 6 characters, include an upper and lower case character and a number
Please enter your first name
Special characters aren’t allowed
Please enter a name between 1 and 40 characters
Please enter your last name
Special characters aren’t allowed
Please enter a name between 1 and 40 characters
You must be over 18 years old to register
You must be over 18 years old to register
Opt-out-policy
You can opt-out at any time by signing in to your account to manage your preferences. Each email has a link to unsubscribe.

Already have an account? sign in

By clicking ‘Register’ you confirm that your data has been entered correctly and you have read and agree to our Terms of use, Cookie policy and Privacy notice.

This site is protected by reCAPTCHA and the Google Privacy policy and Terms of service apply.

Join our new commenting forum

Join thought-provoking conversations, follow other Independent readers and see their replies

Comments

Thank you for registering

Please refresh the page or navigate to another page on the site to be automatically logged in