ESA asteroid mission Hera gears up for launch

Led by the European Space Agency (ESA), Hera is scheduled for launch on a SpaceX Falcon 9 rocket at 15.52 UK time. Its mission will see it fly by Mars in March 2025, before rendezvousing with the asteroid Dimorphos 177m km from Earth in December 2026. There, Hera will study the aftermath of NASA’s Double Asteroid Redirection Test (DART) probe, which slammed into Dimorphos in September 2022.

Hera is part of the international effort to establish a plan to counter an asteroid on a collision course with Earth. We currently know of more than 35,000 asteroids whose orbits are potentially threatening to Earth. Of those, around 1,600 are on ESA’s Risk List. Although none of the 1,600 are large enough to be considered ‘planet killers’, many are large enough to destroy a city.

To mitigate against this threat, DART became humanity’s the first ever attempt to change an asteroid’s orbit. It was deemed a huge success, but the mission raised as many questions as it answered, including the full effects of DART’s 6.1 km/s impact, the size of the crater, and the current mass and makeup of the asteroid. Hera will attempt to answer these questions, revisiting Dimorphos to gather close-up data about the deflected body and turn DART’s experiment into a potentially repeatable planetary defence technique.