Scheduled for lift-off this October, Hera will embark on a two-year journey through space to rendezvous with the Didymos binary asteroid system. The mission's primary focus is the Dimorphos moonlet, comparable in size to the Great Pyramid of Giza, which orbits the larger Didymos asteroid. Hera will study the changes in Dimorphos following NASA's DART mission, which impacted the moonlet and altered its orbit in September 2022. The data Hera gathers will help refine the "kinetic impact" method as a viable planetary defense strategy.

"This is an emotional moment, after a year of intense testing activity," said Paolo Martino, ESA's lead Hera system engineer.

"It feels like a huge accomplishment to have finally concluded the test process because there is always a lot of tension involved in testing, you never be quite sure everything will go to plan. But the best is yet to come, in the shape of the launch itself."

The Hera spacecraft trio was transported overnight to Cologne airport in Germany and will be flown to Cape Canaveral, USA, later today, where they will be launched aboard a SpaceX Falcon 9 in early October.

ESA's Hera team, alongside personnel from European Test Services and prime contractor OHB, witnessed the spacecraft's departure. Paolo Martino noted, "All of us have been working day and night together since the spacecraft got here in August 2023. To make sure we made the tight schedule every moment had to count, and that meant there were no holidays, no nights off or free weekends. Some of the OHB team have had to spend the whole of the last year away from home."

He also highlighted the contributions from Tyvak in Italy, which produced the Milani mineral prospector CubeSat, and Gomspace in Luxembourg, responsible for the Juventas radar mapper. Additional contributions included GMV's work on mission guidance, navigation, and control, OHB Italy's oversight of Hera's power system, Beyond Gravity's solar arrays, and FHP's application of the spacecraft's multi-layer insulation, among others. "It has taken a lot of combined effort to reach this moment," Martino added.

Due to the accelerated timeline of the mission, which saw it move from contract signing to launch readiness in just four years, testing for launch and space environments was combined with functional and software assessments.

As Hera prepared for departure, the team at ESTEC finalized the packing of the spacecraft and completed the necessary documentation for its shipment. Complicating the process was the fact that while some supporting equipment would eventually return from the USA, Hera and its CubeSats would not.

The ESA Hera team will now split into two groups: one heading to Cape Canaveral to oversee final preparations and tests, and the other to ESA's European Space Operations Centre in Darmstadt, Germany, to support Hera's launch and early mission operations.

Hera mission manager Ian Carnelli will bid a brief farewell to the spacecraft as it crosses the Atlantic aboard an Antonov An-124 bound for Cape Canaveral. "This is a significant departure because the very first version of what would later become the Hera spacecraft was worked on here at ESTEC, at our Concurrent Design Facility, nearly two decades ago. It started life as an observer spacecraft called 'Sancho' that was to complement an asteroid impactor spacecraft 'Hidalgo' in ESA's Don Quijote mission concept, which ended up becoming NASA's DART," he explained.

"It's been a long journey, but Hera is almost ready to make history!"

Related Links
Hera at ESA
Asteroid and Comet Mission News, Science and Technology