The team overseeing ESA’s Hera asteroid mission for planetary defence pose with the spacecraft behind them in its ESTEC Test Centre cleanroom in the Netherlands.

They are joined in this photo by representatives from Tyvak International in Italy and GomSpace in Luxembourg – makers of the Milani and Juventas CubeSats respectively, which will join Hera on its journey into deep space – as well as Cheryl Reed of the Applied Physics Laboratory of Johns Hopkins University in the US – seen in the centre – who served as programme manager of NASA’s predecessor planetary defence mission DART (Double Asteroid Redirect Test).

Also represented is ISISpace in the Netherlands, manufacturer of the Deep Space Deployers that will store the miniature CubeSats during their journey to Didymos and deploy them upon arrival.

Hera and DART were conceived together and implemented as the international Asteroid Impact and Deflection Assessment (AIDA) international collaboration. Both missions are supported by a common community of planetary scientists.

On 26 September 2022 the van-sized DART spacecraft impacted the Dimorphos asteroid at around 6.1 km/s. This first test of the ‘kinetic impact’ method of planetary defence succeeded in modifying the orbit of the target asteroid around the larger Didymos body.

This October Hera will commence a two-year odyssey to the Didymos binary asteroid system to perform a close-up asteroid survey, gathering crucial missing information to turn DART’s grand-scale experiment into a well-understood and potentially repeatable planetary defence technique.