The ‘Double Asteroid Redirection Test’ (DART) is the first mission to test technologies for preventing a hazardous asteroid impacting Earth.

DART will reach its target asteroid in late September 2022; the asteroid in question, known as Didymos, is not considered a threat to Earth.

Nasa wants to find out whether 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.

The spacecraft is expected to collide at roughly six kilometres per second and the collision will change the speed of the moonlet in its orbit around the main body by a fraction of 1 per cent.

The craft will also house a cubesat that will separate from it a few days prior to impact, so that it can take photos of Didymos and study changes to the asteroid’s course following the impact.

The space agency’s Launch Services Program, based at Kennedy Space Centre in Florida – the multi-user spaceport in the US – is managing the launch.

Once it has escaped Earth’s atmosphere, the spacecraft will separate from its launch vehicle – a SpaceX Falcon 9 rocket – and will deploy its ‘Roll Out Solar Arrays’ (ROSA) to provide the solar power needed for DART’s electric propulsion system and for the spacecraft operations.

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

“Not only is the DART mission a planetary defense demonstration, but so much of the spacecraft itself is new technology demonstration and being a part of a mission of firsts is stimulating,” said Julie Schneringer, Nasa launch site integration manager.

Next year, researchers from the University of Colorado, Boulder, and Lockheed Martin are planning to launch two small satellites that will be sent to two pairs of binary asteroids to study how these curious space objects evolve and burst apart over time.

In December 2020, the Japanese space program JAXA successfully retrieved a sample of the Ryugu asteroid for scientific study.