DARMSTADT — The control team for the European Space Agency's (ESA) Hera mission completed a software upgrade on the spacecraft, followed by two successful reboots. This operation prepares Hera for its mission phase exploring the Dimorphos and Didymos asteroids in autumn.

Hera launched in October 2024 and is traveling across 140 million km of space at more than 12 km per second. There is a nearly eight-minute one-way signal delay between Earth and the spacecraft. Software installation instructions were relayed using 35-meter diameter communication antennas.

Anna Schiavo, Hera Spacecraft Operations Engineer, said: "The success of this more that two week operation leaves Hera finally ready for what we call its 'asteroid phase'." She added: "The update will allow us to commission all of the spacecraft's remaining instruments and to use the autonomous functionality that Hera will rely on to navigate around its target asteroids – along with the inter-satellite links Hera will employ to communicate with the two CubeSats it will deploy early next year."

The spacecraft's onboard computer utilizes parallel processor streams for redundancy during operations. The software underwent testing for a year and a half at ESA's ESOC mission control center in Darmstadt, Germany. The testing campaign required 50 ground test days.

Sylvain Lodiot, Head of ESA's Outer Solar System and Planetary Defence Operations, said: "The testing involved running the software on a functional replica of Hera located at the mission's prime contractor OHB in Bremen, called the 'Bench', flying around simulated models of the asteroids and communicating with actual CubeSat replicas though the inter-satellite links."

Hera is ESA's first planetary defense mission. In the spring following its launch, Hera performed a flyby past Mars. It is scheduled to perform a close-up survey of the impact site on Dimorphos, which orbits the larger Didymos asteroid. NASA's DART spacecraft impacted Dimorphos in September 2022, making Dimorphos the first object in the Solar System to have its orbit changed by human action.